COVER SHEET FOR PROPOSAL TO THE NATIONAL SCIENCE FOUNDATION PROGRAM ANNOUNCEMENT/SOLICITATION NO./CLOSING DATE/if not in response to a program announcement/solicitation enter NSF 04-23 NSF 05-527 NSF PROPOSAL NUMBER 03/11/05 FOR CONSIDERATION BY NSF ORGANIZATION UNIT(S) FOR NSF USE ONLY 0530756 (Indicate the most specific unit known, i.e. program, division, etc.) CMS - NEES RESEARCH DATE RECEIVED NUMBER OF COPIES DIVISION ASSIGNED FUND CODE DUNS# FILE LOCATION (Data Universal Numbering System) 009214214 EMPLOYER IDENTIFICATION NUMBER (EIN) OR TAXPAYER IDENTIFICATION NUMBER (TIN) IS THIS PROPOSAL BEING SUBMITTED TO ANOTHER FEDERAL AGENCY? YES NO IF YES, LIST ACRONYM(S) SHOW PREVIOUS AWARD NO. IF THIS IS A RENEWAL AN ACCOMPLISHMENT-BASED RENEWAL 941156365 NAME OF ORGANIZATION TO WHICH AWARD SHOULD BE MADE ADDRESS OF AWARDEE ORGANIZATION, INCLUDING 9 DIGIT ZIP CODE Stanford University 651 Serra Street Stanford, CA. 943054125 Stanford University AWARDEE ORGANIZATION CODE (IF KNOWN) 0013052000 NAME OF PERFORMING ORGANIZATION, IF DIFFERENT FROM ABOVE ADDRESS OF PERFORMING ORGANIZATION, IF DIFFERENT, INCLUDING 9 DIGIT ZIP CODE PERFORMING ORGANIZATION CODE (IF KNOWN) IS AWARDEE ORGANIZATION (Check All That Apply) (See GPG II.C For Definitions) TITLE OF PROPOSED PROJECT MINORITY BUSINESS IF THIS IS A PRELIMINARY PROPOSAL WOMAN-OWNED BUSINESS THEN CHECK HERE NEESR-SG: Controlled Rocking of Steel-Framed Buildings with Replaceable Energy Dissipating Fuses REQUESTED AMOUNT PROPOSED DURATION (1-60 MONTHS) 1,600,000 $ SMALL BUSINESS FOR-PROFIT ORGANIZATION 48 REQUESTED STARTING DATE 10/01/05 months SHOW RELATED PRELIMINARY PROPOSAL NO. IF APPLICABLE CHECK APPROPRIATE BOX(ES) IF THIS PROPOSAL INCLUDES ANY OF THE ITEMS LISTED BELOW BEGINNING INVESTIGATOR (GPG I.A) HUMAN SUBJECTS (GPG II.D.6) DISCLOSURE OF LOBBYING ACTIVITIES (GPG II.C) Exemption Subsection PROPRIETARY & PRIVILEGED INFORMATION (GPG I.B, II.C.1.d) INTERNATIONAL COOPERATIVE ACTIVITIES: COUNTRY/COUNTRIES INVOLVED or IRB App. Date HISTORIC PLACES (GPG II.C.2.j) (GPG II.C.2.j) SMALL GRANT FOR EXPLOR. RESEARCH (SGER) (GPG II.D.1) VERTEBRATE ANIMALS (GPG II.D.5) IACUC App. Date PI/PD DEPARTMENT PI/PD POSTAL ADDRESS Civil & Environmental Engineering PI/PD FAX NUMBER 240 Terman Engineering Center Stanford, CA 943054020 United States 650-723-7514 NAMES (TYPED) HIGH RESOLUTION GRAPHICS/OTHER GRAPHICS WHERE EXACT COLOR REPRESENTATION IS REQUIRED FOR PROPER INTERPRETATION (GPG I.E.1) High Degree Yr of Degree Telephone Number Electronic Mail Address ph.d 1988 650-723-0453 [email protected] PhD 1997 650-723-4125 [email protected] PhD 1988 612-626-8225 [email protected] PI/PD NAME Gregory G Deierlein CO-PI/PD Sarah L Billington CO-PI/PD Jerome F Hajjar CO-PI/PD CO-PI/PD Page 1 of 2 Electronic Signature B. PROJECT SUMMARY Our built infrastructure needs to be made less vulnerable and easier to repair after a major earthquake. Of particular concern are certain conventional systems, such as concentrically braced steel frame buildings, which are quite prevalent and designed with excessive reliance on inelastic deformations – often more than they can provide. In the most extreme cases, this can result in a serious life safety risk and, in many other cases, can result in damage that is very expensive to repair. Performance-based earthquake engineering provides an objective means both to assess the performance of conventional systems and to design innovative new seismic resisting systems that can meet the economic and safety needs of modern society. The proposed research aims to develop a new structural building system that employs rocking action and replaceable structural fuses to provide safe and cost effective resistance to earthquakes. The system combines desirable aspects of conventional steel-braced framing (or equally valid, of reinforced concrete walls) with two alternative and complementary fuse concepts – shear panel fuses and axial column fuses. Materials that will be investigated for implementing the fuses are high-performance fiber reinforced cementitious composites and ductile buckling restrained steel components. Guided by performance-based capacity design principles, the fuses are easily replaceable and can be tuned to provide optimal performance. Through controlled rocking of the structure, concerns about damage to foundations and primary structural elements are avoided. The research will take full advantage of complementary features of the NEES MAST facility and Japan’s E-Defense shaking table. With one of the key objectives being to validate the proposed seismic system for reliable use in engineering practice, the E-Defense facility provides the unique capabilities to perform dynamic shake table tests of a nearly full-scale building prototype. Intellectual Merit: The proposed research will lead to seminal advances in concepts, techniques, and models for the design of controlled rocking mechanisms for steel building systems using replaceable energy dissipating fuses. The fuses utilize novel materials and components, including combinations of high-performance fiber reinforced cementitious composite shear panels fuses, low-yield steel shear panel fuses, and buckling-restrained axial column fuses. This combined computational and experimental research investigates both component and complete system response, synthesizing the results through a methodology for performance-based design that directly assesses life safety and life-cycle economic factors. The proposed concept emphasizes damage prevention to foundations and other structural elements that are difficult to repair; inelastic energy dissipation in structural fuses that are easy to replace; story drift control so that nonstructural damage is reduced; and sufficient safety against collapse. The research involves an international NEES/E-Defense collaboration, leveraging U.S. and Japanese facilities and resources. Large-scale experiments will be carried out to validate the systems, coupled with the development of new computational models on the NEESgrid for the novel materials involved. The project team is committed to fully utilizing the simulation, visualization, and collaboration tools of the NEESgrid to dramatically increase the rate of data assimilation, comprehension, and learning, within the context of a distributed international project. Broader Impact: The proposed research is expected to have a major impact on engineering practice, providing the opportunity to design and construct damage tolerant, easy-to-repair, and cost effective structural systems. A detailed data sharing and archiving plan for these complex large-scale tests and parametric simulations will advance the state-of-art in model-based simulation and data archiving. The project leadership team is comprised of co-PI's who are diverse in gender, age, and specialty, and who are geographically well distributed at a non-NEES equipment site and a NEES equipment site. The project has a natural engineering education component through the research participation of graduate and undergraduate students. Diversity initiatives for high school, undergraduate, and graduate students will leverage associations with outreach programs at two major universities and the education program of an NSF-funded EERC. TABLE OF CONTENTS For font size and page formatting specifications, see GPG section II.C. Total No. of Pages Page No.* (Optional)* Cover Sheet for Proposal to the National Science Foundation Project Summary (not to exceed 1 page) 1 Table of Contents 1 Project Description (Including Results from Prior NSF Support) (not to exceed 15 pages) (Exceed only if allowed by a specific program announcement/solicitation or if approved in advance by the appropriate NSF Assistant Director or designee) 20 References Cited 5 Biographical Sketches (Not to exceed 2 pages each) Budget 10 16 (Plus up to 3 pages of budget justification) Current and Pending Support 6 Facilities, Equipment and Other Resources 3 Special Information/Supplementary Documentation 2 Appendix (List below. ) (Include only if allowed by a specific program announcement/ solicitation or if approved in advance by the appropriate NSF Assistant Director or designee) Appendix Items: *Proposers may select any numbering mechanism for the proposal. The entire proposal however, must be paginated. Complete both columns only if the proposal is numbered consecutively. D. PROJECT DESCRIPTION D.1 - Project Participants Table 1. Project Participants Name and Title Gregory G. Deierlein Professor Affiliation Stanford University Principal Investigator Sarah Billington Asst. Prof. Stanford University Co-Principal Investigator Jerome F. Hajjar, Professor University of Minnesota Expertise Role in Project Research management, performance-based earthquake engineering, nonlinear analysis, design of steel and composite steel-concrete structures, development of building code provisions. Design and behavior of structural concrete and HPFRCC materials and systems, computational modeling of cementitious composites. Large-scale structural testing ; nonlinear structural analysis and design; performance-based earthquake engineering. Co-Principal Investigator Helmut Krawinkler Professor Stanford University Performance-based earthquake engineering assessment and design, experimental and analytical simulations. Building Research Institute (Japan) Seismic design and behavior of steel structures, large-scale testing and shake table simulations, Japanese building code standards Other Senior Personnel Mitsumasa Midorikawa Research Coordinator of Building Technology Other Senior Personnel D-1 Project coordination (PI); schematic design and planning of building systems; planning and design of shake table test at EDefense, coordination of education and outreach activities. Time Commitment (mos./year) 2-2-2-2 Planning, design, modeling and testing of HPFRCC shear dissipation panels, collaboration on system test at MAST and EDefense; summer REU advising. 1-1-1-0.5 Planning, design and execution of medium- and large-scale quasistatic system tests; data archiving and curation to NEES repository; project website; education and outreach activities. Design and seismic performance assessment of rocking wall systems, building system studies, coordination of wall-frame system test at E-Defense and large-scale test at UMN. Project coordination of Japanese collaborators, development of braced-frame rocking systems following Japanese construction practice, planning and design of shake table test at E-Defense. 0.75-0.750.75-0.75 0.5-0.50.5-0.5 1-1-1-1 D.2 - Utilization of NEES Equipment Resources, E-Defense and Stanford Experimental Facilities Major testing will be conducted at the NEES Multi-Axial Subassemblage (MAST) Large-Scale Testing System at the University of Minnesota (UMN) and the E-Defense shake table in Japan. In addition, material and small component testing will be conducted in the structural engineering laboratory at Stanford University. Section I (Facilities, Equip., and Other Resources) includes further details on the capabilities at these facilities and Table 2 shows the planned occupation at each site. Table 2. Scheduling for NEES and Major Equipment Site Usage (* = 1 month) Site 10/1/05 – 9/30/06 10/1/06 – 9/30/07 *** UMN Mast *** *** *** *** *** *** 10/1/08 – 9/30/09 *** *** E-Defense Stanford 10/1/07 – 9/30/08 *** *** *** UMN MAST Laboratory: The MAST system will be used to conduct the three-dimensional large-scale quasi-static cyclic tests of the controlled rocking structural systems investigated in this research. These tests will characterize the progressive damage and inelastic response of the structure and will validate the qualities of the system. With the MAST system, six degree-of-freedom control technology is employed to manipulate a stiff steel crosshead that can statically apply combined axial load, shear, overturning moments, and torsion. The system can accommodate structural subassemblages as large as 6.1 m (20 ft.) square in plan and 7.6 m (25 ft.) high. The MAST facility has unique capabilities to apply large gravity loads to the test specimen combined with unified overturning moments and shears that may be applied in a cohesive, coupled fashion to separate bays of the test specimen, thus being able to apply precise loads and displacements to the optimal locations in this frame system to investigate the controlled rocking motions proposed in this research. E-Defense Shake Table: The large 15 x 20 m shake table at the E-Defense facility in Japan will be used to conduct dynamic tests of a large (near full-scale) building system with a hybrid rocking bracedmoment frame system with structural fuses. The E-Defense shake table is required to accommodate the large-scale testing which is critical to investigate the energy dissipating fuse mechanisms and the hybrid braced-moment frame system at a realistic scale. The large scale is necessary to accurately simulate the behavior, which is necessary both from a scientific point of view (accurate representation and understanding of the behavior) and to demonstrate the validity of the new rocking fuse system to engineers and other stakeholders. Apart from its large size, the E-Defense facility provides other benefits. The lab is developing an inertial system to apply gravity loads and seismic mass in multi-story building models. This inertial frame will simplify the shake table test setup and make the test more economical. Another benefit is that this proposed project will leverage financial and intellectual resources of a companion Japanese project that will be funded by the Japanese government (see supporting letter from Dr. Nakashima, Director of E-Defense). STANFORD Structural Engineering and Materials Lab: The Structural Engineering and Materials Lab at Stanford University has a strong floor and several loading frames that can be used for development testing of the shear panel fuses. The laboratory is equipped with loading actuators, measurement transducers, and data acquisition systems. The lab also houses equipment for fabrication, curing and testing of high performance fiber reinforced cementitious composite (HPFRCC) materials. For materials testing there are two MTS testing machines; one is an 89 kN (tension/compression), fatigue rated machine with hydraulic grips, the second is a 245 kN (tension/compression), fatigue rated machine with a 1 x 2 meter loading table. This facility has access to the high-speed Internet-2 and can be used for internet-based collaboration (e.g. telepresence) and NEES data archiving for this project. D-2 D.3 - Strategic Research Vision Introduction: Recent advancements in performance (or consequence) based earthquake engineering have provided objective means for assessing the performance of conventional structural systems, but equally or more importantly, they provide effective techniques for developing and assessing new innovations that will make our future stock of buildings less vulnerable to earthquake damage and easier to repair after a seismic event. In conventional seismic systems reliance is placed on the primary structural components deforming inelastically and thereby dissipating the energy imparted to a structure by a major seismic event. Very often, insufficient attention is paid in conventional designs to balancing initial costs with life cycle considerations, which include estimation of direct losses due to structural and nonstructural damage, downtime losses, and repair of structural damage, in addition to life safety considerations. The work proposed here addresses all these issues in the contexts of developing and testing innovative fused rocking (pivoting) systems that limit the extent of structural damage and provide for quick, efficient, and cost effective repair. The concept of structural fuses is not new, but it has not been sufficiently developed because of past inability to provide an objective assessment of their costs and benefits. Now the means for an objective assessment exist, and the emphasis of research needs to shift to the development of cost-effective design improvements. There are two ways to approach future system design. One is to improve incrementally on conventional systems. The second, which is the approach taken in this proposal, is to devise new systems that provide higher performance with greater resiliency. Let us use braced steel frames as an example. They are known to be vulnerable because of questionable post-buckling behavior of braces (which may fracture) and because of great difficulties in designing brace connections and column base plates that can sustain significant inelastic deformations (see Section D.4.1). Improvement to conventional braced frames will help, but a more effective design solution is to avoid all the conditions that create undesirable behavior of braces and connections. This is where the fuse concept comes to bear, as its implementation intends to prevent undesirable behavioral modes. The fuse concept has several objectives, including the following: • Provide story drift control so that drift sensitive nonstructural damage is reduced • Provide floor acceleration control so that acceleration sensitive nonstructural and content damage is reduced (e.g., in a hospital or a museum) • Provide controlled structural damage that can cost effectively be repaired after a major earthquake • Prevent damage to foundations and other elements that are difficult to repair, and • Provide sufficient safety against collapse. Proposed Braced-Frame Fuse System: As illustrated in Fig. 1, the proposed research focus is on the development of a seismic force resisting system that combines desirable aspects of conventional steel-braced framing (or equally valid, of reinforced concrete walls) with two alternative and complementary fuse concepts – shear panel fuses and axial column fuses. The framing configurations shown are two examples of possible Figure 1 – Pivoting Braced Frame (a) single bent with shear variants that can be envisioned with this dissipating panels, (b) dual bent with shear dissipating panels and system. The underlying concept of the axial dissipating strut system utilizes controlled rocking (pivoting) and a capacity design approach to concentrate inelastic deformations in the fuse components. The configuration of Fig. 1a demonstrates the application of a shear panel fuse, where energy is dissipated D-3 through the large shear strains developed across the shear panel between the braced frames. For a given story drift, the magnitude of shear strain energy dissipated in the panel is proportional to the ratio of the dimensions of the braced panel to the shear panel, i.e., the dimensions B/A shown in Fig. 1a. Thus, by altering the geometry, one can achieve large amplifications in shear deformations, whereby large amounts of energy can be dissipated at low drifts. Ideally, the shear panels should have a large elastic stiffness, a well defined yield point, and large energy dissipation capacity. Two materials that will be investigated for the shear panels are high-performance fiber reinforced cementitious composites (HPFRCC) and lowyield steel plates. The panels are connected to the frame with bolts (or dowels) and are designed for easy access and replacement. This is in contrast to conventional systems, such as eccentrically braced steel frames or coupled shear walls, where the shear links are integral with the structural system and difficult to repair once they are damaged. Likewise, the inelastic hinge regions of moment frames are integral to the structural frame and difficult to repair. The configuration shown in Fig. 1b demonstrates the use of axial column fuses, which can either be designed to work on their own or in combination with the shear dissipation panels. The axial deformations of a fuse are related to the bay width by the ratio of bracing panel width to story height (A/H). One way to implement the axial column fuses is through the use of buckling-restrained columns (BRCs), similar in concept to buckling-restrained braces (BRBs) that have been successfully introduced into design practice over the past ten years [1]. Like their BRB counterparts, the BRCs would be designed to dissipate energy through large inelastic deformations of a steel core, which is prevented from buckling by some type of housing (often a steel tube filled with concrete). Another candidate for the axial column fuse is a yielding base plate, such as Midorikawa et al. [2] have studied. The configuration of Fig. 1b demonstrates where it may be advantageous to employ both axial column and shear panel fuses, so as to improve response or redundancy of the systems. For optimal building performance, the fused bracing systems (Fig. 1) are intended for use with a parallel system that provides an elastic restoring force. As suggested by the framing plan in Fig. 2, we envision that the parallel system to be a flexible moment resisting steel frame. The combination of the stiff fused braced frame and the flexible frame offers several advantages over conventional systems or either system acting alone. By balancing the strength, stiffness, and inelastic deformation characteristics of the two systems, the goal is for the moment frame to remain essentially elastic under the design earthquake, thereby providing a restoring force that will reduce (or even eliminate) residual drifts. This is in contrast to conventional dual systems, where both systems are expected to deform inelastically and their interaction is unknown. After large earthquakes, when the fuses may be damaged, the moment frame will stabilize the system while the fuses are removed and replaced. Figure 2 – Schematic framing plan for hybrid system: energy dissipating braced frames with elastic moment frames Performance-Based Design: Recent advances in performance (or consequence) based assessment and design [3-7] have made it possible to assess the benefits of various design enhancement techniques objectively by incorporating increases in up-front construction costs and projected benefits in terms of reduced losses (direct losses and downtime losses) and increased (or collapse) safety. D-4 Illustrated in Fig. 3 is the Hazard Structural System Domain method that will be employed Domain to assess the value of the proCollapse Hazard Curves Mean IM-EDP Curves posed braced system with fuses Fragility Curves for Design Alternatives for Design for Design Alternatives [8]. This method will address E ( EDP | IM & NC ) Alternatives the issues of losses in nonγ=0.2 γ=0.1 T =0.9 sec. γ=0.3 λ(IM) P(C | IM ) γ=0.2 γ=0.1 T =1.8 sec. γ=0.3 structural drift sensitive subSa(T )/g Sa(T )/g Sa(T )/g Sa(T )/g systems (NSDSS), nonstructural acceleration sensitive subsystems (NSASS), the T =0.9sec. structural subsystem (SS), and T =1.8sec. the issue of losses due to collapse. Provided that intensity measure (IM) hazard P(C|Sa(T )/g) IDRavg. FAavg. µavg. curves and mean loss– λ(Sa(T )/g) engineering demand parameter NSDSS NSASS SS (EDP) curves of the Expected subsystems are known (or can Total $Loss (in millions) be estimated), this figure illustrates how various structural systems can be EDP=Avg. of max. EDP=Avg. of max. EDP=Avg. of max. story drift ratios, evaluated using the mean IMfloor accelerations, stories ductilities, IDR FA (g) µ EDP curves of structural E ( $ Loss | EDP & NC ) E ( $ Loss | C ) systems without and with fuses. $Loss Curves $Loss Value As alternative configurations (No Collapse) (Collapse) are tested, the properties of the structural system can be tuned $Loss Domain such that the system’s IM-EDP Figure 3. Illustration of conceptual performance-based design process curve shows explicitly how much can be gained by utilizing the fuses, measured in terms of loss reduction and improved collapse safety. Use of the fuses will come at a cost whose benefits can be assessed from the reduction in losses. 1 1 1 1 1 1 2.0 2.0 2.0 2.0 1.5 1.5 1.5 1.5 1.0 1.0 1.0 1.0 0.5 0.5 0.5 0.5 1 1 0.0 0.005 0.01 0.015 0.02 0.025 Expected Subsystem $Loss ( in millions) 10/50 2/50 0. 5 0.0 0.5 1.0 1.5 2.0 2.0 4.0 6.0 0% 50% 100% 1 12.0 12.0 12.0 10.0 10.0 10.0 8.0 8.0 8.0 6.0 6.0 6.0 4.0 4.0 4.0 2.0 2.0 2.0 0.0 0.0 0.005 0.01 0.015 0.02 0.025 avg. 0.0 0.5 1.0 avg. 1.5 2.0 Expected Total $Loss at Collapse ( in millions) 50/50 1 2.0 4.0 6.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 avg. These concepts for performance-based design are an extension of performance-assessment tools, which have been developed through research supported by the NSF (e.g., the Pacific Earthquake Engineering Research Center, http://peer.berkeley.edu, the Mid-America Earthquake Center, http://mae.ce.uiuc.edu), FEMA (e.g., FEMA 273 and ATC 58), and other organizations. NEES/E-Defense Collaboration: The proposed research will be an international collaboration between US and Japanese participants and will utilize the NEES MAST and the E-Defense facilities. With one of the key objectives being to validate the proposed system for use in engineering practice, the E-Defense facility provides the unique capabilities to perform dynamic shake table tests of a nearly full-scale building prototype. The research topic is of mutual interest to the Japanese researchers and industry. A team under the leadership of Dr. Midorikawa (Research Coordinator of Building Technology at the Japanese Building Research Institute) has been identified; and, as indicated in the attached letter from Dr. Nakashima (Director of E-Defense), funding for Japanese collaborators has been secured. The co-PI’s have a long history of collaboration with Japanese researchers, and over the course of developing this proposal we have corresponded extensively with Dr. Nakashima and Dr. Midorikawa. They both are enthusiastic about collaborating with us on this project, and we have included Midorikawa as a co-leader to direct the proposed collaborative testing at the E-Defense facility. Should this proposed be funded, we also expect that the Japanese will become involved in the proposed testing at the NEES MAST facility and send visiting researchers to the U.S. D-5 D.4 - Background and Literature Review D.4.1 Seismic Design and Performance of Steel Braced Frame Systems The performance of braced frames in earthquakes has been a major concern for researchers and engineers for many years. Until 1985, there was no specific requirement in the UBC to design bracing connections for anything but a 25% increase in the code seismic design forces. Since then, code requirements have tightened and the present requirements are to “design the connection for the maximum force, indicated by analysis, that can be transferred to the brace by the system” [9]. But recent earthquakes and laboratory experimental studies have shown that this general requirement does not safeguard sufficiently against post-buckling fracture of braces or against brittle failure modes in brace-to-brace, brace-to-column/beam, and columnto-base plate connections. Undesirable behavior has recently been demonstrated in tests of a steel braced frame that was designed according to current seismic design standards (AISC 2002). As shown in Fig. 4 [10], not only did the inelastic deformations concentrate in one story, but they further localized in local buckles that led to premature fracture under cyclic loading. Other studies have raised similar concerns Figure 4. Brace Buckling Failure Observed in Lab [11,12] as have many local and global failures of braced frame structures in recent earthquakes [13, 14], see Fig. 5. The brittle connection failures have a multitude of sources, including fracture of net sections, impact loads due to straightening of slender members, out-ofplane buckling of gusset plates, fracture at weldments due to gusset plate buckling, or fracture in very thick base plates such as those of the Oviatt Library in the 1994 Northridge earthquake [13, 15]. Clearly much research has yet to be done to evaluate and quantify each failure mode and its consequences, and building code detailing provisions should be revised considerably, to safeguard against all failure modes that may significantly affect the safety of braced frame structures. Moreover, it is very likely that postelastic behavior in braces and their connections in an earthquake will require extensive and costly repair actions. For these reasons it should be a most attractive alternative to avoid all these undesirable failure modes by designing braces and connections such that they respond elastically, and calling upon controlled energy dissipation modes in which the dissipative mechanisms are predictable, reliable, and easily replaceable. This is the objective of the proposed work. D.4.2 Controlled Rocking (Pivoting) Seismic Systems Figure 5. Collapse of a Braced Frame, Kobe Earthquake, 1995 One of the two energy dissipating fuse mechanisms to be investigated is that associated with controlled rocking (or pivoting) at the base of a braced frame. In concept, this mechanism can be represented by adding a rotational base spring whose yield moment and elastic and post-elastic stiffness provide the mechanism for controlling the force transfer into the structure. If the spring yield moment is zero, the consequence is unrestrained pivoting. Analytical studies (see Section D.4.6) will identify what spring properties best serve the objective of achieving desirable performance. Knowing the desired characteristics, the challenge is to achieve these through energy dissipating pivoting mechanisms that are (a) cost effective, (b) reliable, and (c) easily replaceable after a damaging event. D-6 The pivot point itself may consist of a mechanical (true) pivot, or more likely a compact region of steel that is designed to undergo cyclic rotations without damage. Most of the energy dissipation is expected to come from devices inserted between the chords of the braced frame (or wall) and the foundation. Potentially attractive devices are buckling restrained columns and other steel elements that dissipate energy effectively in bending or shear (or in friction in case of friction damping devices). As one example Midorikawa [2] has conducted shake table tests of a rocking braced frame that employs a flexural fuse in the base plate (Fig. 6). Tipping Mar Associates, a Bay Figure 6. Rocking base fuse by Midorikawa et al. [2]. Area Consulting Firm, is proposing to use a similar system, with plate bending in steel angle sections to dissipate energy at the base of a rocking braced frame and prestressed cables along the chord members as a self-centering mechanism [personal communication]. There are many options for cost effective and replaceable energy dissipation devices at the base of pivoting braced frames (or walls) that can and will be explored in this work. The concept of improving performance through either controlled or even uncontrolled rocking is not new. Already Housner looked into the potential benefits of rocking [16]. Meek [17] conducted analytical investigations into the behavior of a flexible single-degree-of-freedom system (inverted pendulum) on an unbonded rigid foundation mat. He concluded that a reduction in base shear, upwards of 20%, is evident during tipping when compared to a bonded system. Shaking table tests performed at the University of California, Berkeley on a 9-story steel frame without tension tie-downs [18] experimentally demonstrated that there is a distinct reduction in system base shear during transient uplift. They recorded a 30% reduction in base shear and corresponding overturning moment in the test frame due to rocking. Other important fundamental work on modeling rocking and/or foundation uplift is published in [19, 20]. An interesting and related concept of a sliding concave foundation was recently introduced in [21]. Ajab et al. [22] performed an analytical study in which rocking of wall-frame structures was augmented with supplemental tendon systems to enhance damping. These and other studies (such as those performed on rocking of bridge piers [e.g., 23, 24]) will form the background on which the proposed project will build. The literature review has disclosed that in appropriate configurations rocking indeed is a beneficial mechanism that can be taken advantage of to improve seismic performance. The review has also disclosed that the proposed mechanisms, which rely on shear dissipating panels made of HPFRCCs and on axial dissipation mechanisms, have not been a subject of thorough study. The potential benefits of such mechanisms are illustrated in Section D4.6. D.4.3 Buckling Restrained Braces As mentioned previously with respect to Fig. 1b, components similar to buckling restrained braces BRBs are envisioned as an attractive way to implement the axial column fuses in the lowest story of a braced frame. Buckling restrained braces consist of a steel core (e.g., a plate or tube) surrounded by steel tubes, concrete confined by an external tube, or other arrangements that enable the steel core to yield symmetrically in tension or compression, in particular without buckling while in compression. The great advantage of these elements is that they have already found widespread application in the US, Japan and Taiwan, that they are commercially available, and that much experimental research has been performed on their cyclic behavior and their application as bracing elements. Recent research on buckling-restrained braced frames provides an excellent foundation for understanding strength, stiffness, and ductility of these components. Many component and system studies of BRB frames have been conducted [e.g., 25-35] and have shown that systems designed with braces such as are currently available can provide high levels of D-7 ductility and can be designed for large drifts. These components show stable, symmetric hysteretic response, as illustrated in Fig. 7 from a typical experimental test. D.4.4 High Performance Fiber Reinforced Cementitious Composites High Performance Fiber-Reinforced Cementitious Composites (HPFRCC) are an example of a damage-tolerant, energy dissipating material that that will be investigated for use as shear panels between the proposed rocking braced frames. The HPFRCC we will investigate exhibits fine, multiple Figure 7. Cyclic response of a BRB [25] cracking and a strain hardening response in direct tension. The material is micromechanically designed to achieve this response using a small volume fraction of polymeric fibers, typically less than 2% by volume [36].When HPFRCC is reinforced with steel, the two materials exhibit compatible deformation where both reach several percent strain when yielding [37]. As a result, bond stresses are low and typical failures due to bond splitting and spalling are not observed. Additionally, overall strength is increased (because the HPFRCC unlike concrete, can carry tension to large strains) and larger portions of the steel can yield than is the case with traditional reinforced concrete, allowing for larger hysteretic energy dissipation. HPFRCC materials have been investigated recently for several applications for seismic resistance [38-44]. In all cases, a consistent finding has been the extreme damage-tolerance of the material, in that the multiple fine cracks close almost completely upon unloading, after large cyclic lateral displacements (e.g. 10% drift) and no spalling is observed in compression. HPFRCC can be precast or cast-in-place in large volumes. Most closely related to this proposal is the research on shear behavior [45-47] and infill panel applications [40] using HPFRCC materials combined with mild steel reinforcement. Shear stress vs. strain results from Ohno shear beam tests [48] are shown in Fig. 8. Only the reinforced concrete specimen contained mild steel. The HPFRCC systems (mix 1 with metal fibers and mix 2 with polymeric fibers) performed very well in comparison with the concrete and traditional FRC specimens despite having no conventional shear reinforcement. These results demonstrate how different HPFRCC mix designs can be used to give different properties whether it be higher strength or higher ductility. Furthermore, a recent study on infill panels subjected to a lateral shear load demonstrated that reinforced HPFRCC could result in over 60% larger hysteretic energy dissipation than a reinforced concrete panel with the same reinforcement ratio (Fig. 9) [40]. Finally, connection details of these infill systems have verified the ability of the material to be connected using pre-tensioned bolts and withstand cyclic loading [46, 49]. This establishes HPFRCC panels as replaceable components on a story-by-story basis. However, alternative details such as using Applied Load (kN) 60 Actuator HPFRCC mix 1 HPFRCC Panel Reinforced concrete HPFRCC mix 2 40 20 0 -2.50% -1.50% -0.50% 0.50% 1.50% -20 Plain concrete -40 HPFRCC-1 HPFRCC-2 Reinf. Concrete -60 Figure 8 Shear stress vs. strain cement-based materials [45] Figure 9 Hysteretic response of infill panels [40] D-8 2.50% Drift (%) low strength steel on either side of the HPFRCC panel to form a sandwich system may prove attractive. Prior research by Hossain and Wright [50] has shown ductile monotonic response of composite infill wall systems that use corrugated metal deck with infill concrete. Zhao and Astaneh [51] have proposed a steel plate shear wall system with reinforced concrete attached to one side of the steel plate with bolts to help mitigate shear buckling of the plate. The system showed excellent ductile response. Based upon alternative details such as those seen in prior research, in this work, the most cost-effective, ductile, and replaceable use of HPFRCC shear panels will be explored. D.4.5 Nonlinear Modeling and Simulation of Seismic Response Nonlinear analyses that accurately simulate the inelastic response of structures are essential for performance-based earthquake engineering assessment and design, particularly with regard to simulating the initiation of damage up to the onset of collapse. Our plan is to utilize OpenSees [52] which is well suited to this research and has recently been adopted as a computational simulation component of NEESgrid. OpenSees provides a versatile object-oriented framework, with modeling capabilities to capture large-deformation stiffness and strength degrading response of structures subjected to large earthquake ground motions [53-54]. Matlab prototyping tools [55] available through NEESgrid provide the ability to conveniently develop and test new models, such as will be required to simulate the HPFRCC shear panel fuses. In previous research, the PI and his students have implemented element and material models to simulate inelastic behavior and large deformation response in beam-columns and beam-column joints [5758]. Other researchers have applied OpenSees to (a) exercise emerging performance-based assessment techniques to evaluate the performance of real buildings and bridges [59], (b) simulate the response of a pseudo-dynamic test of a full-scale composite frame [60], and (c) simulate shake table tests of a steel frame with fracturing connections [61]. D.4.6 Performance of Pivoting Braced Frame with Energy Dissipation The concepts of performance assessment for tuning the properties of braced frames with fuses to produce desirable behavior have been illustrated in Fig. 3. Using braces with base fuses as part of a braced frame – moment frame hybrid system, the following parameters can be varied to tune the behavior: moment frame stiffness and base shear strength, braced frame stiffness and strength assuming a fixed base, and pivoting rotational stiffness of the braced frame. It is the combination of these six global system parameters that will govern the quality of performance. The following simple example, a study of four structures subjected to a suite of 40 ground motions scaled to a high earthquake hazard, illustrates the effect of these variables. The base structure, designated as “frame” in Fig. 10, is a 9-story moment-resisting frame with a first mode period of 1.8 sec. and a base shear capacity of 0.1W (details of the frame are presented in [63]). This frame is the common element in three other dual moment-braced frame systems. In all three combinations the braced frame stiffness is equal to twice the moment frame stiffness. The variant called “fixed” in Fig. 10 has an infinitely strong braced frame with a fixed base. The other two cases have a rotational spring at the base. The case called “pin” has zero rotational stiffness, whereas the cased called “fuse” has a rotational stiffness comparable to the frame and a yield moment equal to 0.13WH. The first mode periods of the four configurations are 1.8 sec. for frame and pin, 1.26 sec. for fuse, and 0.96 sec. for fixed. The median roof drift ratios of the four configurations are 1.5%, 1.4%, 1.1%, and 0.9%, respectively for frame, pin, fuse and fixed. Median values of pertinent response parameters are compared in Figs. 10a-c. The story drift profiles clearly show the benefit of stiffening with braced frames. The benefit of adding an energy dissipating fuse, is comparable to that achieved by adding a fixed base braced frame, except in the lower stories. Hinging the braced frame at the base, pin, forces the interstory drift to be rather uniform over the height, with the maximum interstory drift of about 60% of that of the moment frame. Consistent patterns are observed also for story shear force and overturning moment demands. Both are increased by the addition of braced frames, by a very large amount for the fixed base braced frame, and by much smaller amounts by letting the base pivot freely or providing an energy dissipating fuse. D-9 The conclusion suggested by this study is that the widespread use of fixed base braced frames (or shear walls) is an often ineffective way of achieving desirable performance. It requires the transfer of large shear forces and overturning moments within the structure and to the foundation, and is not very effective in reducing interstory drifts, with the possible exception of lower stories. This makes a strong case for exploring hinged braced frames (or shear walls) and braced frames with energy dissipating fuses. In the analytical studies, this will be investigated, with the objective being to provide definitive design guidelines for selecting relative strength and stiffness properties to achieve desired performance with in the context of the performance criteria illustrated in Fig. 3. Additional performance objectives are ease of replacement of damaged fuses, and self-centering of the structural system due to the elastic strain energy stored in the moment frame after removal of damaged fuses. z/H z/H z/H Maximum Interstory Drift Profiles (Medians) The shear force and over1 turning moment demands on the fixed base braced (a) 0.75 frame are large and imply the need for “inelastic” de0.5 fixed sign and reliance on large frame 0.25 “ductility” capacity. This fuse pin raises challenges associated frame fixed pin; 0 with inelastic response of 0 0.005 0.01 0.015 0.02 0.025 0.03 fuse Max IDR conventional braced frames, Maximum Story Shear Profiles (Medians) Maximum Floor Over Turning Moment Profiles (Medians) ranging from undesirable 1 1 post-buckling behavior of (b) (c) 0.75 braces, to difficulties in de0.75 signing gusset plates and 0.5 0.5 base plates so that they perframe fixed fixed form well when braces 0.25 0.25 frame buckle or columns get fuse pin pin fuse 0 overloaded, to great diffi0 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 0.6 Max Shear / W culties in repairing foundaMax OTM / WH tion and structural damage Figure 10. Median Story Responses of 9-story Structures (a) Interstory Drifts, (b) after a strong earthquake. Story Shears, (c) Story Overturning Moments All these difficulties can be mitigated by employing the proposed fuse concepts, which concentrate inelastic behavior in the replaceable fuses and shelter the braced frame from excessive force demands. D.5 Objectives and Research Outcomes Objectives: The primary objective of the proposed research is to advance the state-of-art in the research and practice of earthquake engineering, through the rigorous performance-based development of an innovative new concept of pivoting braced systems with energy dissipating fuses. Included within this overall vision are the following specific objectives: 1. Develop new strategies for the seismic design of building systems that are guided by explicit focus on the performance objectives of damage control under moderate to large earthquakes and collapse safety as well as economical repair under major earthquakes. 2. Mitigate earthquake life safety and economic risks to society by the introduction of new structural systems that utilize new materials and design concepts, based on advanced understanding of structural response gained through complementary computational and physical simulation. 3. Advance understanding related to the seismic design of hybrid structural systems that combine inelastic energy dissipating components with elastic restoring systems. D-10 4. Increase our knowledge and use of high-performance fiber reinforced cementitious composite materials and low-yield steels for inelastic fuse applications in seismic design. 5. Revitalize earthquake engineering education to emphasize innovative design through the introduction of new materials and system innovations. Expected Outcomes and Original Contributions: Our research vision is conceived to provide seminal advances in earthquake engineering research, education and engineering practice. To successfully impact all three of these areas, the proposal will explore new concepts, which while quite novel in concept are readily amenable to implementation with construction materials and methods that have received comprehensive testing at the component level and initial successful use in other related seismic applications. Expected outcomes and original contributions include: 1. Development of a new approach to seismic design, suitable for all seismic zones, predicated on controlled rocking of steel building systems coupled with replaceable energy dissipating fuses. Through controlled rocking, foundation construction costs associated are reduced, and energy dissipation occurs in replaceable components that ensure cost-effective and safe structures. These systems will be developed within the context of a new methodology for performance-based design that directly addresses the losses to structural as well as non-structural components (e.g., through control of story drifts and floor accelerations). The final deliverable will synthesize this research with related past work to propose appropriate design provisions suitable for adoption in practice. 2. Adoption of new materials and components, including HPFRCC, low-yield strength steel, bucklingrestrained columns, and braced-frame pivots, being used to their best advantage for practical construction applications that help mitigate serious seismic deficiencies in conventional construction. Both constitutive modeling and large-scale testing of these materials and components will underpin the validation testing conducted in the NEES facilities and E-Defense. 3. Creation of the NEES/E-Defense initiative, whereby new collaborations will be forged with Japanese partners at E-Defense with mutual investigation of these systems through integrated computational and physical simulation, including testing that imposes three-dimensional loading at both US and Japanese facilities, one through quasi-static cyclic testing, the other through dynamic shake table testing. These facilities thus enable premier validation of the rocking fuse structural systems so as to expedite their acceptance into practice. D.6 Strategic Research Plan As illustrated in Fig. 11, the research plan is organized around a central spine of activities that integrate the data and results of the experimental simulations into a coherent systems design approach, culminating in the development of design implications and recommendations for the new structural framing systems. The details associated with each task are described later in sub-sections of Section 7.1. Briefly, the main features of the plan are the following: Task 1 – Schematic Design of Prototype Systems: Much like in engineering design practice, the research will begin with a detailed schematic design effort to articulate and quantify the important issues and parameters for the subsequent experimental and analytical studies. Performance-based design thinking will guide this effort with consideration given to life-cycle and post-earthquake repair costs. Task 2- Computational Simulation: As schematic designs are developed, computational models will be created and tested to simulate the nonlinear seismic response of the structures. Included will be development of models to simulate unique features of the rocking behavior and inelastic fuses, utilizing existing data on low-yield and BRB steels (from previous research) and HPRFCC panels (obtained from Task 3). Task 3 – Characterization and Design of HPFRCC Panels: Guided by sizing and performance parameters identified through the schematic design effort of Task 1, this task will focus on the development of HPRFCC panels. Data from HPRFCC material and panel testing and computational modeling will D-11 provide input to characterize the panels response in the macro-simulations (Task 2) and large-scale validation tests at MAST (Task 4). A complementary effort (upper right box of Fig. 11) will synthesize data on BRBs and low-yield strength steel for energy dissipation. Task 4 – Development and Large-Scale Validation of Energy Dissipating Rocking Frames (MAST): This task integrates data from the schematic designs, computational simulation results, HPFRCC shear panel study (Tasks 1 to 3), low-steel shear panel and BRC elements, to design and test the rocking braced frame subassembly and fuses. Quasi-static tests will be conducted at large scale in the MAST facility, with the primary goals to (a) Figure 11 – Strategic Research Plan characterize the shear panel and axial column fuses, and (b) validate that the system and components (e.g., the brace pivot) work as intended. Task 5 – Parametric Design and Performance Evaluation of Building Systems: Building upon the schematic designs (of Task 1), the simulation models (Task 2), and the experimental simulation data (Tasks 3 and 4), the parametric design studies pull together the information to conceive and assess a number of alternative designs. One outcome of this task will be data to plan and design the shake table specimens to be evaluated at E-Defense (Task 6). The other outcome will be information feeding into the design implications and recommendations of Task 7. Task 6: Large-Scale Shake Table Simulation (E-Defense): Data, models and knowledge gained from Tasks 1-6 will be synthesized and validated through the planning, design and simulation testing of a large-scale frame on the E-Defense shake table. The frame will be designed as a test bed to permit simulation of alternative fuse concepts and will be a focal point of US-Japan research collaboration. Task 7 – Design Implications and Recommendations: The data and information collected and made accessible through NEES-grid will provide a unique opportunity to accelerate research dissemination on rocking braced systems with fuses into engineering practice. Design implications and recommendations will be developed with the participation of professional engineering organizations. D6.1 Detailed Project Tasks Task 1: Schematic Performance-Based Design of Prototype Systems -- Input and participation from engineering practitioners will be applied in the structural design of a variety of prototype building systems that utilize the fuse details. These will serve as prototypes for computational and physical simulations in subsequent tasks. The structures will be hybrid systems that involve the energy dissipating braced-frames acting in combination with moment frames. The plan configurations and number of stories will be varied as needed to cover the range of likely building applications. Likewise, the merits of alternative braced frame-fuse configurations will be evaluated. At least 20 prototype structures will be designed and documented, using a performance-based approach, for the desired performance targets. For comparison with conventional practice, the resulting designs will be compared to the strength and stiffness requirements of existing design provisions for standard concentrically and eccentrically braced steel frames. The number of stories will be varied from 2 to 20 to cover D-12 the full range of configurations for which the proposed rocking braced-frames designs may be economically feasible and structurally effective. The schematic frame designs will be analyzed using the nonlinear computational simulation models described under Task 2 in order to provide an initial performance evaluation in terms of the global engineering demand parameters (peak and residual interstory drifts, peak floor acceleration) and local cumulative damage indices in the fuses. Task 2: Computational Simulation of Energy Dissipating Rocking Braced Frame Systems -- The research will make extensive use of nonlinear analysis to simulate the inelastic response of the building framing systems, including braced frames, moment frames, and the inelastic fuses. Computational simulations will be conducted using OpenSees (http://opensees.berkeley.edu/), the features of which were described previously in Section D.4.5. In addition to creating and analyzing building system models using existing features of OpenSees, this research will include the development, implementation, and calibration of component models to simulate the inelastic hysteretic properties of the various fuse types. The fuse mechanisms will be implemented as concentrated multi-degree of freedom springs. Development and implementation of the models will be coordinated and validated through the other tasks dealing with system and component (braced frame and fuse) performance. Building system response will be evaluated using nonlinear static (pushover) and inelastic time history analyses. The latter will be conducted using a strategy termed “incremental dynamic analysis”, where key parameters of the system response are evaluated under increasing intensities of earthquake ground motions [62, 64]. The analyses will make use of reliability tools in OpenSees to characterize the sensitivity of the building performance to uncertainties and design variations of the input parameters – particularly those associated with the relative stiffness of the braced-frame to moment-frame in the elastic and inelastic response realms. A Task 3: Characterization and Design of HPFRCC Energy Dissipating Shear Panels -- To develop the energy-dissipating shear panels for the large-scale rocking braced frame tests will require HPFRCC Shear Panel two main research tasks: (1) Finite element (FE) modeling to identify optimal HPFRCC properties and their combination with steel reinforcement, and (2) Reduced-scale panel testing to evaluate panel properties and verify connection detail A-A A behavior. FE modeling will be used to identify the Figure 12 Shear panel test set-up trade-offs of stiffness, strength and energy dissipation with various materials and reinforcement details. For instance, as the percentage of fine aggregate in HPFRCC is increased, the stiffness will increase but the ductility will decrease, thus reducing the ability of the HPFRCC-steel combination to dissipate significant hysteretic energy. The finite element modeling will build upon recent research on modeling HPFRCC materials under cyclic loading [40, 41, 44, 65, 66], including rate dependent tests on HPFRCC that are currently underway at Stanford. Based on the finite element modeling, various combinations of reinforcement and HPFRCC mix design will be investigated under quasi-static cyclic shear loading to verify strength, stiffness, ductility and damage to the shear panels. The reduced-scale panels will be tested as shown in Fig. 12. The experiments will also serve to validate again the robustness of the bolted connections. A sandwich panel design using HPFRCC will also be investigated for potential advantages in reduced damage and ease of replacement. Task 4: Development and Large Scale Validation of Energy Dissipating Rocking Braced Frame Components (MAST) -- A series of experiments will be conducted in the MAST Laboratory to investigate the cyclic performance of the braced-frame rocking system and components. Figure 13 shows a typical configuration of the test specimen for a multi-story, multi-bay braced frame system with HPFRCC shear panels, low-yield steel shear panels, BRC energy dissipating fuses, and structural pivots D-13 at the base of the system. The dimensions will reflect those of the braced bent in the lower stories of the prototype structures studied in Task 1, modeled at approximately one-third to one-half scale. This setup will permit testing of several configurations of HPFRCC shear panels, the low-yield steel shear panels, the axial column fuses, the pivots at the base connections, and the connections of these components to the braced frame. The crosshead will be attached to pinned loading attachment points for each individual braced frame to permit more independent motion of each frame, as shown in the figure. Quasi-static loading will be primary in-plane (including gravity loading) with modest out-of-plane (orbital) loading to simulate the realistic loads and deformations that would be experienced in a real building. The purpose of these tests is to document the progressive inelastic response and damage in the complete rocking system, with a primary focus on assessing the detailed response and robustness of the fuses, the pivot assembly of the braced frames, and the connections of the fuses (both the HPFRCC and low-yield steel shear panel fuses and BRC axial column fuses) to the braced frames. Because the energy dissipating fuses are replaceable, several tests will be conducted using the braced frame system. The shear panel fuses will be tested without axial column fuses, as well as with pairs of column fuses as shown in Fig. 13, or with four column fuses as shown in Fig. 1. The specimens will be heavily instrumented so as to provide comprehensive information for Task 7 on performance-based design of this structural system. The Krypton system will also be ideal for documenting both the rocking component of the motion and the shearing response of the HPFRCC and/or low-yield steel panels. Telepresence Plan at MAST: The MAST Laboratory provides premier capabilities for remote teleparticipation for the other project participants, including those in Japan. Teleobservation will be achieved through a set of ten remotely-controllable digital video cameras with directional audio microphones and eight remotely-controllable high-resolution digital still image cameras spaced around the perimeter of the specimen, and through an array of sensors (e.g., strain gages, displacement sensors, and rotation sensors). Each video and still image camera is mounted on a robotic arm that can be extended vertically to increase the coverage of the camera. Integrated teleoperation is provided for all cameras and the robotic towers so that project participants may interact directly with the viewing environment. It is envisioned that the project participants will work as a team during the experiments to study the response and make decisions about the appropriate loading protocols. This is critical for this project, as it permits the contributions of each researcher to this project to be brought to bear on the execution of these pivotal tests. All sensor, video, audio, and still image information is streamed out over Internet2 for both private clients (i.e., project participants and other interested researchers) and public clients (see discussion in Section D.7 on education and outreach). Interfaces have been developed and integrated into NEESgrid for use of these MAST-specific features, providing a content rich environment to facilitate detailed scientific interactions during these experiments. Task 5: Parametric Design and Performance Assessment of Energy Dissipating Rocking Braced Frame System -- Performance evaluation of the complete structural system is a key aspect of the proposed research. The performance evaluation will be conducted using the basic framework methodology, originally developed within the PEER Center and now being translated into design guidelines through the ATC 58 effort. The primary engineering performance metrics will be those related to reparability (as inferred from residual drifts and damage accumulation in the fuses) and safety (as inferred through the mean annual frequency of collapse). The engineering demand parameters (EDPs) will be processed through D-14 Figure 13. Schematic Test Specimen of Steel Braced Frame with Replaceable Energy Dissipating Devices for MAST Laboratory fragility (loss) curves to determine generalized decision variables, such as annualized losses to structural and nonstructural systems and building content. A matrix of performance criteria will be established, which will serve as the basis for an objective evaluation of various design options, including conventional braced frame and moment frame designs and appropriate energy dissipating rocking systems. The performance will be evaluated using incremented nonlinear time history analyses using the OpenSees platform, including statistical evaluation of response data at various levels of intensity. The variables that will receive attention in this parametric design and performance evaluation include: • • • • Building configuration variables, such as plan size and number of stories Relative strength and stiffness of energy dissipating braced frame and elastic moment frame Systems with alternative fuse types and configurations, including single versus multiple fuses Ground motion variables (intensity, frequency content, near-fault effects, etc.) Task 6: Large Scale Validation of Energy Dissipating Rocking Braced Frame System (E-Defense) -The large-scale frame tests planned for the E-Defense shake table in Japan will integrate the results from Tasks 1 to 5 and serves as a focal point to facilitate international research collaboration. The shake table simulations, representing salient features of the complete structural system, will provide unprecedented understanding of the interactive effects of braced frame rocking, energy dissipative fuses, and the elastic restoring frame system. Conducting the tests at full-scale (or near full-scale) is important to accurately represent the interactive behavioral effects of components and systems in the structural frame, the fuses and their connections to the frame, and the slab/concrete floor deck. Our schematic design for the fourstory test frame (see Fig. 14) is configured to provide a versatile test-bed that can be used to evaluate multiple types of fuse dissipaters. Aside from its large size and capacity, the E-Defense facility is developing an innovative inertial mass system, which will dramatically simplify and reduce the cost of the shake table test. As one of the important outcomes of the large-scale test is validation of our computational simulation models, detailed response prediction analyses will be conducted prior to testing (using OpenSees) and we will encourage outside researchers to make blind predictions of the response. The E-Defense facility is uniquely suited to perform this ultimate validation test. It is the only one available, worldwide, that permits closeto-full-scale shake table testing of a comprehensive assembly that replicates all important interactions taking place between all the components of a complete structure. Such a validation test cannot be accomplished elsewhere, and it comes at a small cost because of the great interest and extensive complementary efforts of the Japanese project collaborators. Task 7: Design Implications and Recommendations -The combined experimental and analytical studies of Tasks 1 to 7 will result in a wealth of data and quantitative information that need to be synthesized to become of direct use to the engineering professions in the US and Japan. The targeted audiences for these design recommendations are code committees, guideline writers, professional organizations, and individual practicing engineers. We will D-15 Figure 14. Schematic Steel Frame Specimen for E-Defense Shake Table Test present concepts for these design implications and recommendations at least once per year to our external advisory board, which will include several leading structural and earthquake engineering practitioners. In particular, working committees of ongoing guideline development efforts, such as ATC 58, BSSC, and the SEAOC Seismology Committee will be consulted during the course of this research and invited to teleparticipate in testing. The PI (Deierlein) is a member of the ATC 58 committee, co-PI’s Hajjar and Billington are active in other organizations that create standards (ASCE, ACI, FEMA, etc.). Midorikawa, our Japanese counterpart, is active in building code committees of the Architectural Institute of Japan. D6.2 Project Implementation Team Organization, Management Plan, and Schedule: The project leadership team is diverse; led by a PI from a non-NEES equipment site, with co-PI’s from both NEES and non-NEES sites; faculty are at different stages in their careers, of different genders, and with different specialties (structural materials, computational simulation, and earthquake engineering); our external advisory board of practicing structural engineers will have strong input; and our Japanese collaborator is assembling a complementary research team in Japan. The organizational chart for our project is shown in Fig. 15. The management is divided between four major initiatives, three of which encompass the major research task, with the fourth being education and outreach (described in Sec. D.7). All the investigators and students will work integrally on the project, with each of the co-PI’s having a lead responsibility in one of the major thrusts. Within each initiative are specific sub-tasks, which are the primary responsibility of the individuals listed. The project will support three PhD students, each of whom will have the lead role on one component of the research with supporting roles on other tasks. A functional budget for the overall project is provide in Sec. D6.5, which is supplemented by further details in the full budgets and budget justifications presented later. The schedule of the proposed tasks (as described in Figure 15 – Project Management Organization the previous section) is summarized in Table 3. During the development of this proposal, the co-PI’s have solicited input from practicing engineers and developed effective working relationships, which they look forward to continuing throughout the project. Input from a group of practicing structural engineers and building constructors will be formalized through the creation of an external advisory board to whom the co-PI’s will provide with periodic updates and meet with annually. The co-PI’s are already making regular use of commercial teleconference and webmeeting facilities, and they look forward to utilizing the enhanced collaboration technologies offered Table 3 - Timing and Scheduling of Research Tasks Proposed Task Task 1 – Schematic Designs Task 2 – Comp. simulations Task 3 – HPFRCC Panels Task 4 – Braced Bent w/Fuses Task 5 – Parametric Designs Task 6 – Braced Frame w/Fuses Task 7 – Design implications Report and Paper Publication 10/05 – 3/06 ****** *** ****** 4/06 – 9/06 ** ****** ****** *** *** D-16 10/06 – 3/07 ** ****** ****** ****** ****** ** 4/07 – 9/07 Dates 10/07 – 3/08 ** ****** ****** ****** *** ** ****** ****** ****** ****** ** ** 4/08 – 9/08 10/08 – 3/09 ** ** ****** ** ** ****** ****** ** ****** ****** ** 4/09 – 9/09 ***** ****** ****** through the NEESgrid. Interaction between the co-PI’s and sites is expected to be an on-going activity, with formally scheduled web-meetings occurring at least once per quarter over the course of the project, with at least one in-person meeting each year. Risk Mitigation: All of the co-PI’s and senior personnel have experience with large projects involving multiple organizations, large-scale testing, and international collaboration. As such, they appreciate the challenges and risks to successful completion of the project. Details of a formal risk management plan will be established upon the project award. Briefly, our primary strategy for risk mitigation will be through (a) careful planning of the research activities, (b) paying careful attention to activities that can be impacted by external factors (e.g., lab delays) and are on the critical path, (c) continuous monitoring of our own progress, and (d) effective communication with team members, equipment sites, NEESinc, contractors, and others whose work progress will affect the overall project schedule. Budgeting of large tests is another concern. We have been in contact with the UMN-MAST and E-Defense facilities, and we think we have an accurate assessment of the testing expenses built into our budget. In the event of unforeseen cost over-runs (e.g., larger than expected bids from contractors to build the specimens) we do have contingency plans to reduce test specimen sizes and modify the testing scope if necessary. Use of NEESGrid Resources: NEESgrid resources are integrated into this research and education plan in four fundamental ways: • Telepresence activities as discussed in Task 4 (with similar expectations for Task 6 at E-Defense) • Data sharing and archiving plans as discussed in Section D.6.3 • Education and outreach plans, specifically through the establishment of a public telepresence website as discussed in Section D.7 • Extensive utilization and model development for the OpenSees platform [Tasks 2, 5], which has been adopted as part of NEESGrid. D6.3 Data Sharing and Archiving Plan and Dissemination to Earthquake Engineering Community The MAST Laboratory provides outstanding facilities related to archiving of all sensor data (including resistance strain sensors, displacement and rotation sensors, and 3D deformation data measured by a Krypton LED-based system), video and audio data, and still image data. This data is synchronized and archived on site at the MAST Laboratory during the experiment. Subsequent to the test, curation of the data to the NEES national data repository is enabled with assistance from the MAST Laboratory staff. The investigators have been leaders in advising on the establishment of data models and policies for data curation within NEES (Hajjar sits on both the NEES Information Technology Committee and the NEES Data Sharing and Archiving Committee; Deierlein and Krawinkler are on the NEES Board of Directors, which has reviewed and approved these policies). It is our intent that this project serve as a model for data curation, data sharing, and documentation of the research. Prior to conducting any experiments or substantial analyses as part of this project, we will work with our students and the staff at MAST, EDefense, and NEESit to (1) establish key elements of data and metadata for timely and comprehensive data documentation and curation, and (2) develop algorithms for data analysis and processing, such that processed test data can be viewed and compared to analytical simulations during the tests. These steps will help ensure that the data and metadata is posted to the NEES national data repository, consistent with the policies of the NEES Consortium, Inc. We are committed to the NEES policy of uploading and releasing the processed data to the NEES national data as soon as practically possible, and certainly within the maximum timeframe specified in the data policies set by the NEES Board. Staff and student time at the equipment sites have been budgeted for this effort. A similar archiving of OpenSees data will be executed for all significant structural analyses conducted in this research. Significant findings will be promptly submitted for publication in journals, workshops, seminars and conferences, and comprehensive documentation will be published in report series (such as the proposed NEES electronic journal). All investigators will utilize membership and/or committee services in D-17 professional organizations, such as EERI, ASCE, SEAOC, AISC, ACI, BSSC, and SSRC to communicate findings so as to bring research results to engineering practice in an effective and timely manner. Finally, during the last year of the project, we will hold a small workshop with our advisory board and other invited select experts from academia and practice, where we present our research findings to facilitate technology transfer. D6.4 Payload Projects Payload projects provide excellent opportunities for leveraging the proposed work and for broadening participation. We will actively encourage other researchers, particularly younger faculty and faculty from underrepresented groups, to collaborate. Possible payload projects for this research include: (1) Investigating alternative fuse designs, by re-using the rocking braced frame specimens at the MAST or EDefense facilities; (2) Developing alternative column rocking base connections through additional testing on the MAST specimen; (3) Exploring new technologies for recording and interpreting three-dimensional measurements (e.g., laser-based displacement measuring devices); and (4) detailed 3D continuum modeling to complement testing and macro-analysis to be performed in this project. D6.5 Functional Budget The functional budget of Table 4 provides a breakdown of the allocation of resources between the various categories of research, education/outreach, and data archiving/sharing. All of the figures include indirect charges (i.e., gross charges) and reflect the personnel and other supporting costs associated with each activity. So, for example, in addition to the direct costs of the frame test specimen, the funding allocation to the E-Defense testing includes the portion of salary and travel costs associated with the co-PI and graduate students for time spent planning and conducting the frame test at E-Defense. Specimen Disposal: Budgets for testing include costs for specimen disposal at the MAST and E-Defense facilities (see detailed budget justifications). Table 4 - Functional Budget (Total $) ITEM Experimental Research Stanford NEES-MAST E-Defense Non-Experimental Education and Outreach Data Archiving/Sharing TOTAL Year 1 80,000 62,798 44,000 52,718 32,500 16,250 288,266 Year 2 57,000 194,618 166,140 69,734 33,800 33,800 555,092 Year 3 0 90,372 244,920 107,752 35,152 35,152 513,348 Year 4 0 14,976 100,088 55,114 36,558 36,558 243,293 Cumulative 137,000 362,764 555,148 285,318 138,010 121,760 1,600,000 D.7 Education, Outreach, and Training As indicated in the management organization chart (Fig. 15), plans for education and outreach contribute significantly to project plans. Four major education and outreach components are planned for the project: (1) project website and public teleparticipation, (2) outreach to high-school students, (3) research involvement for undergraduate students, and (4) research involvement for graduate students. Creating opportunities for students from under-represented minority groups is emphasized throughout the plan by leveraging associations with existing programs and initiatives at the participating universities, the participating NEES site, and the Pacific Earthquake Engineering Research (PEER) Center - the latter being facilitated by three of the co-PI’s (Deierlein, Krawinkler, and Billington) involvement in PEER’s research and education programs (see http://peer.ucsd.edu/). All activities will be coordinated and linked with the NEES Consortium education and outreach activities. Website and Teleparticipation: A project website will be created to promote research collaboration among the research team and outreach to other researchers, students, and the public. The site will provide D-18 a schedule of testing, with links to teleparticipation resources at the MAST NEES and E-Defense sites to permit observation of the test and test data as it is being generated through the public client teleparticipation interface. This project-specific website for public telepresence will include content about the research status (particularly ongoing experimental testing) targeted for four different age levels (e.g., primary school, secondary school, the general population and the primary target audience of undergraduates in all fields). Outreach to High School Students: The UMN Civil Engineering Department has an ongoing relationship with four Minneapolis high schools, with large under-represented minority populations (50 to 85%), which teach a nationally certified pre-engineering curriculum, Project Lead the Way (PLTW). The UMN EERI Student Chapter (for which Hajjar serves as advisor) currently engages these schools as well as elementary and middle schools with demonstrations on earthquake engineering, including use of a model shake table. Co-PI Hajjar will invite PLTW high school teachers to the MAST Laboratory for a half-day workshop to help shape an educational module on earthquake engineering research. Involvement of Undergraduate Students: Undergraduate students at the University of Minnesota and will be involved on an ongoing basis as laboratory assistants at the NEES site. Beyond this, the project has targeted plans for participation of under-represented minority groups in an Earthquake Engineering Scholars Course (hosted annually by the educational program of the PEER Center) and summer research internships at one or more of the sites. Funding has been allocated to involve undergraduate summer intern students during each year of the project. Addition funds to support one or two undergraduates from Stanford are likely to be available through a program supported by the Stanford Vice Provost for Undergraduate Education. Student recruitment will be done through existing mechanisms of the Engineering Diversity Program (http://emp.stanford.edu/EDP/) at Stanford University, the PEER Educational Affiliate Program, recruiting visits by the co-PIs to selected schools with large under-represented minorities. Involvement of Graduate Students: This project will provide research support for three PhD students. Our goal is for at least one of these students to be from an under-represented minority group. The co-PI’s are committed to actively recruiting diversity students, through the undergraduate programs described above and through programs offered by the Stanford School of Engineering Diversity Programs (http://soe.stanford.edu/edp/home/index.html), which has dedicated fellowship funding for graduate students from under-represented minorities. D.8. Intellectual Merit and Broader Impacts on Earthquake Engineering Research and Practice Intellectual Merit: The proposed research will lead to seminal advances in concepts, techniques, and models for the design of controlled rocking mechanisms for steel building systems using replaceable energy dissipating fuses. The fuses utilize novel materials and components, including combinations of high-performance fiber reinforced cementitious composites (HPFRCC) shear panels fuses, low-yield steel shear panel fuses, and buckling-restrained axial column fuses. This combined computational and experimental research investigates both component and complete system response, synthesizing the results through a methodology for performance-based design that directly assesses losses in structural and nonstructural components. The proposed concept emphasizes preventing damage to foundations and other structural elements that are difficult to repair; localizing damage in elements that are easy to replace; providing story drift control so that nonstructural damage is reduced; and providing sufficient safety against collapse. The research includes an international NEES/E-Defense collaboration with Japan, leveraging US and Japanese facilities and resources. Large-scale experiments will be carried out to validate the systems, coupled with the development of new computational models on the NEESgrid for the novel materials involved. The project team is committed to fully utilizing the simulation, visualization, and collaboration tools of the NEESgrid to achieve a seminal increase in the rate of data assimilation, comprehension and learning, within the context of a distributed international project. Broader Impact: The proposed research is expected to have a major impact on engineering practice, providing the opportunity to design and construct damage tolerant, easy-to-repair, and cost effective D-19 structural systems. A detailed data sharing and archiving plan for these complex large-scale tests and parametric simulations will advance the state-of-art in model-based simulation and data archiving. The project leadership team is comprised of co-PI's who are diverse in gender, age, and specialty, and who are geographically well distributed at two non-NEES equipment sites and a NEES equipment site. The project has a natural engineering education component through the research participation of graduate and undergraduate students, including three Ph.D. students, undergraduate assistants, and summer undergraduate research scholars. Using mechanisms available both externally and within this project, the co-PIs are committed to attract and involve under-represented minority graduate, undergraduate, and high-school students in various phases of the research. Diversity initiatives for undergraduate and graduate students will leverage associations with the Engineering Diversity Program at Stanford University and the education program of the NSF-EERC PEER Center. Outreach to diversity students at high schools will be facilitated by collaboration with Project Lead the Way at the UMN NEES site. D.9 Results of Prior NSF Support Deierlein, G.G., (CMS-9632502, CMS-9896368, 9/1/96-7/31/00, $240,000) “Seismic Design and Behavior of Composite RCS Frames” Part of the US-Japan Cooperative Research Program on Composite and Hybrid Structures, the outcome of this project were: 1) development of nonlinear analysis methods to evaluate the seismic performance of composite steelconcrete frames, 2) development of improved seismic design requirements for composite construction, and 3) formulation of plans for a large-scale validation test. The project resulted in a methodology to assess the collapse limit state of frame structures that incorporates a cumulative damage index for composite frame components to account for uncertainties introduced by earthquake ground motions. This project culminated in a pseudo-dynamic test of a full-scale three-story composite frame conducted through subsequent collaboration with researchers in Taiwan. One masters student and two PhD students participated in this project, publications include [39, 68, 69]. Billington, S. (CAREER Award, CMS-9984127 and CMS-0342940: July 00-June 04, $276,000.) “Innovative Materials for Civil Infrastructure Education and Research” This project involved course development and research on high-performance fiber-reinforced cement-based composites (HPFRCC) in precast, post-tensioned bridge piers for seismic regions. A course entitled, Structural Materials Testing and Simulation, which combines physical experiments and computational simulation, has been offered 3 times at the undergraduate and graduate levels. Small-scale precast bridge column tests and large-scale column tests using HPFRCC were completed. Pilot creep and shrinkage tests on HPFRCC were performed. A constitutive model for cyclic and seismic 2D nonlinear finite element analysis of HPFRCC was developed. Research on assessing the impact of introducing new structural systems and materials to construction practice through life-cycle cost modeling continues from this project. One Masters student, two PhD students and two Postdoctoral researchers have been supported. Publications include [40, 44, 65] along with twelve conference papers. A. E. Schultz, J. F. Hajjar, and C. K. Shield (CMS-9632506, 9/15/96-8/31/00, $253,896). “Seismic Behavior of Steel Moment-Resisting Frames with Composite RC Infill Walls.” This project included an experimental and computational research program for the study of steel moment-resisting frames with composite reinforced concrete infill walls subjected to seismic excitation. A one-third scale frame was tested quasi-statically to determine the cyclic behavior of steel frame-RC infill composite wall systems. Twelve full-scale cyclic shear specimens, comprised of steel wide-flange sections connected with shear studs to a concrete panel, were tested to quantify the strength of stud connections under cyclic shear and axial tension. Data analysis coupled with linear and nonlinear system analyses and prototype structure design served to establish preliminary analysis and design recommendations. One Ph.D. student and one M.S. student, selected references [70-76]. H. Krawinkler (PEER/NSF Project 3382003, 10/1/2003–3/31/2005, $90,000) “Criteria for Performance-Based Design” In this project the main goal was to develop criteria and procedures for performance-based design (PBD) that permit direct (rather than iterative) design of frame and wall structures for multiple performance objectives associated with limit states of relevance for a subsequent rigorous performance assessment. This involved focusing on discrete performance targets associated with discrete hazard levels and proportion structural systems for strength, stiffness (drift limitations), and ductility based on expected losses and an acceptable probability of collapse. Two Ph.D. students, selected references, [8, 77-84]. D-20 SECTION E – REFERENCES 1. Sabelli, R. (2004). “Recommended Provisions for Buckling-Restrained Braced Frames,” Engineering Journal, Vol. 41, No. 4, pp. 155-175. 2. Midorikawa, M., Azuhata, T., Ishihara, T. and Wada, A. (2003). “Shaking Table Tests on Rocking Structural Systems Installed Yielding Base Plates in Steel Frames,” Proceedings of STESSA 2003 (4th International Conference on Behaviour of Steel Structures in Seismic Areas), pp. 449-454, Naples, Italy, June 9-12, 2003. 3. Cornell C. A., Krawinkler H. (2000). “Progress and challenges in seismic performance assessment,” PEER News, April 2000. 4. Krawinkler, H. (2002). “A general approach to seismic performance assessment,” Proc. International Conference on Advances and New Challenges in Earthquake Engineering Research, ICANCEER Hong Kong, August 19-20, 2002, Vol. 3: 173-180. 5. Deierlein G. (2004). “Overview of a comprehensive framework for earthquake performance assessment,” Proc. International Workshop on Performance-Based Seismic Design – Concepts and Implementation, Bled, Slovenia, 15-26. 6. Krawinkler H, and Miranda E. (2004). Performance-based earthquake engineering,” Chapter 9 of Earthquake Engineering: from engineering seismology to performance-based engineering, CRC Press: 9-1 to 9-59. 7. Abrams, D. P., Elnashi, A. S., and Beavers, J. E. (2001). “A New Engineering Paradigm: Consequence-Based Engineering,” http://cbe.civil.tamu.edu/html/CBEDefinition.html, 12 pgs. 8. Krawinkler, H., Zareian, F., Medina, R.A., and Ibarra, L. (2004). “Contrasting Performance-Based Design with Performance Assessment,” Performance-Based Seismic Design – Concepts and Implementation, Proceedings of an International Workshop held in Bled, Slovenia, June 28 – July 1, 2004, pp. 505-516. 9. AISC (2002). “Seismic Provisions for Structural Steel Buildings” AISC, Chicago, IL. 10. Uriz, P., and Mahin, S. (2004). “Summary of Test Results for UC Berkeley Special Concentric Braced Frame Specimen No. 1 (SCBF-1), CEE Dept., UC Berkeley, http://www.ce.berkeley.edu/~patxi/SCBF/publications/PrelimSCBFtestResults.pdf 11. Kim, H. I., Goel, S. C. (1996). “Upgrading of Braced Frames for Potential Local Failures,” Journal of Structural Engineering, ASCE, Vol. 122, No. 5, pp. 470-475. 12. Tremblay, R., Timler, P., Bruneau, M., and Filiatrault, A. (1995). “Performance of Steel Structures During the 1994 Northridge Earthquake,” Canadian Journal of Civil Engineering, Vol. 22, No. 2, April 1995, pp. 338-360. 13. EERI (1996). “Northridge Earthquake Reconnaissance Report, Vol. 2,” Earthquake Spectra, January 1996. 14. BRI (1996). “A Survey Report for Building Damages due to the 1995 Hyogo-Ken Nanbu Earthquake,” Building Research Institute, Ministry of Construction, Tsukuba, Japan. 15. Oviatt Library Damage, http://library.csun.edu/mfinley/quake.html 16. Housner, G. W. (1963). “The Behavior of Inverted Pendulum Structures During Earthquakes,” Bulletin of the Seismological Society of America, SSA 52(2). 17. Meek, J. W., (1975). “Effects of Foundation Tipping on Dynamic Response,” Journal of the Structural Division, ASCE, Vol. 101, No. ST7. 18. Huckelbridge, A. A and Clough, R. W. (1978). “Seismic Response of Uplifting Building Frame,” Journal of the Structural Division, ASCE, Vol. 104, No. ST8. E-1 19. Priestley, M. J. N., Evison, R. J. and Carr, A. J. (1978). “Seismic Response of Structures Free to Rock on Their Foundations,” Bulletin of the New Zealand Society for Earthquake Engineering, Vol. 11, No. 3, pp. 141-150. 20. Yim, C. S. and Chopra, A. K. (1985). “Simplified Earthquake Analysis of Multistory Structures with Foundation Uplift,” Journal of Structural Engineering, ASCE, Vol. 111, No. 12. 21. Hamidi, M., El Naggar, M.H., Vafai, A., and Ahmadi, G., (2003). “Seismic Isolation of Buildings with Sliding Concave Foundation (SCF),” Earthquake Engineering and Structural Dynamics, Vol. 32, pp. 15-29. 22. Ajrab, J.J., Pekcan, G., and Mander, J.B. (2004). “Rocking Wall-Frame Structures with Supplemental Tendon Systems,” Journal of Structural Engineering, ASCE, Vol. 130, No. 6, pp. 895-903. 23. Palermo, A., Pampanin, S., and Calvi, G. M., (2004). “Use of Controlled Rocking in the Seismic Design of Bridges,” Proceedings, 13WCEE, Paper No. 4006. 24. Sakellaraki, D., Watanabe, G, and Kawashima, K. (2005). “Experimental Rocking Response of Direct Foundations of Bridges,” Proceedings, Second International Conference on Urban Earthquake Engineering, Tokyo Institute of Technology, March 2005, pp. 497-504. 25. Merritt, S., Uang, C. M., and Benzoni, G. (2003). “Subassemblage Testing of Corebrace Bucklingrestrained Braces,” Report No. TR-2003/01, Department of Structural Engineering, University of California, San Diego. 26. Tremblay, R. (2000). “Influence of Brace Slenderness on the Seismic Response of Concentrically Braced Steel Frames,” Proceedings of the STESSA 2000 Conference, Mazzolani, F. and Tremblay, R. (eds.), Montreal, Canada, Balkema, Rotterdam, pp. 527-534. 27. Sabelli, R. (2001). “Research on Improving the Design and Analysis of Earthquake-Resistant Steel Braced Frames,” NEHRP Fellowship Report No. PF2000-9, Earthquake Engineering Research Institute, Oakland, California. 28. Tsai, K.-C. and Huang, Y.-C. (2002). “Experimental Responses of Large Scale Buckling Restrained Brace Frames,” Report No. R91-03, Center for Earthquake Engineering Research, National Taiwan University, Taipei, Taiwan. 29. Aiken, I. D., Mahin, S. A., Uriz, P. (2002). “Large-Scale Testing of Buckling Restrained Braced Frames,” Proceedings of the Japan Passive Control Symposium, Tokyo Institute of Technology, Yokohama, Japan. 30. Bolduc, P. and Tremblay, R. (2003). “Experimental Study of the Seismic Behaviour of Steel Braces with Concrete Filled Tube and Double Steel Tube Buckling Restrained Mechanisms,” Report No. EPM-GCS-2003-01, Department of Civil, Geological and Mining Engineering, École Polytechnique, Montréal, Canada. 31. Fahnestock, L. A., Sause, R., and Ricles, J. M. (2003). “Analytical and Experimental Studies on Buckling Restrained Braced Composite Frames,” Proceedings of the International Workshop on Steel and Concrete Composite Construction (IWSCCC-2003), Report No. NCREE-03-026, National Center for Research in Earthquake Engineering, Taipei, Taiwan, October 8-9, 2003, National Center for Research in Earthquake Engineering, Taipei, Taiwan, pp. 177-188. 32. Sabelli, R., Mahin, S. and Chang, C. (2003). “Seismic Demands on Steel Braced Frame Buildings with Buckling Restrained Braces,” Engineering Structures, Vol. 25, No. 5, pp. 655–666. 33. Uang, C.-M. and Kiggins, S. (2003). “Reducing Residual Drift of Buckling-Restrained Braced Frames as a Dual System,” Proceedings of the International Workshop on Steel and Concrete Composite Construction (IWSCCC-2003), Report No. NCREE-03-026, National Center for Research in Earthquake Engineering, Taipei, Taiwan, October 8-9, 2003, National Center for Research in Earthquake Engineering, Taipei, Taiwan, pp. 189-198. E-2 34. Black, C. J., Makris, N., and Aiken, I. D. (2004). “Component Testing, Seismic Evaluation and Characterization of Buckling Restrained Braces,” ASCE, Journal of Structural Engineering, Vol. 130, No. 6, pp. 880-894. 35. Tremblay, R., Poncet, L., Bolduc, P., Neville, R., and DeVall, R. (2004). “Testing and Design of Buckling Restrained Braces for Canadian Application,” Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, British Columbia, Paper No. 2893, submitted for publication. 36. Li, V.C. and Leung, C.K.Y., (1992). “Steady State and Multiple Cracking of Short Random Fiber Composites,” ASCE J. of Engineering Mechanics, Vol. 118, No. 11, pp. 2246 – 2264. 37. Fischer, G. and Li, V. C. (2002). “Influence of Matrix Ductility on Tension-Stiffening Behavior of Steel Reinforced Engineered Cementitious Composites (ECC),” ACI Structural Journal, Vol. 99, No. 1, pp. 104-111. 38. Parra-Montesinos, G., and Wight, J. K. (2000). “Seismic Response of Exterior RC Column-to-Steel Beam Connections,” Journal of Structural Engineering, ASCE, Vol. 126, No. 10, pp. 1113-1121. 39. Parra-Montesinos, G., (2003). “HPFRCC in earthquake-resistant structures: current knowledge and future trends,” Proceedings of HPFRCC-4, Ann Arbor, Michigan, U S A. June, pp.453-472. 40. Kesner, K. E, and Billington, S. L, (2004). “Investigation of Infill Panels made from Engineered Cementitious Composites for Seismic Strengthening and Retrofit,” ASCE J. Structural Engineering, in press. 41. Horii, H., Matsuoka, S., Kabele, P., Takeuchi, S., Li, V.C., and Kanda, T. (1998). “On the Prediction Method for the Structural Performance of Repaired/Retrofitted Structures,“ in Fracture Mechanics of Concrete Structures Proceedings FRAMCOS-3, AEDIFICATIO Publishers, D-79104 Freiburg, Germany, Oct., pp. 1739-1750.. 42. Fukuyama, H., Iwabuchi, K. and H. Suwada, (2004). “HPFRCC Device for Structural Control of RC Buildings with Soft Story,” Proceedings of BEFIB, Varenna, Lake Como, Italy, Sept., pp1163-1172. 43. Fischer, G., and Li, V. C., (2003). “Intrinsic Response Control of Moment Resisting Frames Utilizing Advanced Composite Materials and Structural Elements,” ACI Structural J., Vol. 100, 2, 166-176. 44. Billington, S. L, and Yoon, J. K, (2004). “Cyclic Response of Precast Bridge Columns with Ductile Fiber-reinforced Concrete,” Journal of Bridge Engineering, ASCE, 9(4): 353-363. 45. Li, V. C., Mishra, D. K., Naaman, A. E., Wight, J. K., LaFave, J. M., Wu, H. C., and Inada, Y. (1994). “On the Shear Behavior of Engineered Cementitious Composites,” Journal of Advanced Cement Based Materials, Vol. 1, No. 3, pp. 142-149. 46. Kanda, T., S. Watanabe and V. C. Li (1998). “Application of Pseudo Strain Hardening Cementitious Composites to Shear Resistant Structural Elements,“ in Fracture Mechanics of Concrete Structures Proceedings, FRAMCOS-3, AEDIFICATIO Publishers, D-79104 Freiburg, Germany, pp. 1477-1490. 47. Xia, Z. M. and Naaman, A. E. (2002). “Behavior and Modeling of Infill Fiber Reinforced Concrete Damper Element for Steel-Concrete Shear Wall,” ACI Structural Journal, Vol. 99, No. 6, NovemberDecember, pp. 727-739. 48. Arakawa, T. and Ono, K. (1957). Transactions of the Architectural Institute of Japan, Vol. 57, pp. 581-584 (in Japanese). 49. Kesner, K. E., and Billington, S. L., (2003). “Experimental Response of Precast Infill Panel Connections and Panels Made With DFRCC,” Journal of Advanced Concrete Technology, 1(3): 1-7. 50. Hossain, M. and Wright, H. D. (2004). “Performance of Double Skin-Profiled Composite Shear Walls – Experiments and Design Equations,” Canadian Journal of Civil Engineering, Vol. 31, No. 2, pp. 204-217. 51. Zhao, Q. H. and Astaneh-Asl, A. (2004). “Cyclic Behavior of Traditional and Innovative Composite Shear Walls,” Journal of Structural Engineering, ASCE, Vol. 130, No. 2, February, pp. 271-284. E-3 52. http://opensees.berkeley.edu 53. Fenves, G. L., Filippou, F. C., and McKenna, F. (2002). “The OpenSees Software Framework for Earthquake Engineering Simulation,” Special Seminar Abstract, Proceedings of the 2001 ASCE Structures Congress, ASCE, Reston, VA. 54. McKenna, F. and Fenves, G. L. (2000). “An Object-Oriented Software Design for Parallel Structural Analysis,” Advanced Technology in Structural Engineering, Proceedings of the 2000 ASCE Structures Congress, ASCE, Reston, VA. 55. Filippou, F. C., “FEDEASLab LT, A Matlab Toolbox for Linear and Nonlinear Structural Analysis,” SEMM Report, pp. 1-29, 2001/07. 56. Kaul, R., Deierlein, G. G. (2002). “Generalized Hinge Models with Strength and Stiffness Degradation,” Proc. of 2002 Structures Congress, Denver, CO, April 2002, ASCE, Reston, VA. 57. Altoontash, A. and Deierlein, G. G., (2003). “A Versatile Model for Beam-Column Joints,” Proceedings of 2003 ASCE/SEI Structures Congress, ASCE, Reston, VA. 58. Deierlein, G. G., Kaul, R., (2002). “Methodology and Simulation Models for Performance-Based Earthquake Engineering,” The Third U.S.-Japan Workshop on Performance-Based Earthquake Engineering Methodology for Reinforced Concrete Building Structures, PEER-2002/02, Pacific Earthquake Engineering Research Center, Richmond, CA. 59. PEER Testbeds, http://www.peertestbeds.net/. 60. Cordova, P., Deierlein, G. G., Chen, C-H, Lai, W-C, Tsai, K-C (2004). “Pseudo-dynamic Testing of a Full-Scale RCS Frame: Part 2 – Analysis and Design Implications,” Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, Canada, Paper 674. 61. Rodgers, J.E., Mahin, S., A. (2004). “Effects of Connection Hysteretic Degradation on the Seismic Behavior of Steel Moment-Resisting Frames,” PEER 2003/13, PEER, Richmond, CA. 62. Vamvatsikos, D., and Cornell, C.A. (2002). “Incremental Dynamic Analysis,” Earthquake Engineering & Structural Dynamics, Vol. 31, No. 3, pp. 491-514. 63. Medina, R., and Krawinkler, H., (2003). “Seismic Demands for Nondeteriorating Frame Structures and Their Dependence on Ground Motions,” John A. Blume Earthquake Engineering Center Report No. TR 144, Department of Civil & Environmental Engineering, Stanford University, and PEER Report 2003/15. 64. Krawinkler, H., Medina, R., and Alavi, B. (2003). “Seismic Drift and Ductility Demands and Their Dependence on Ground Motions,” Engineering Structures, Vol. 25, No. 5, March, pp. 637-653. 65. Han, T. S., Feenstra, P. H., and Billington, S. L. , (2003). “Simulation of Highly Ductile Fiberreinforced Cement-Based Composites under Cyclic Loading,” ACI Structures Journal, Vol. 100, No. 6, pp. 749-757. 66. Kabele, P. (2003). “New Development in Analytical Modeling of Mechanical Behavior of ECC” Journal of Advanced Concrete Technology, Vol. 1, No. 3, pp. 253-264. 67. Mehanny, S. S., and Deierlein, G. G., (2001). “Seismic damage and collapse assessment of composite moment frames,” Journal of Structural Engineering., ASCE, Vol. 127, No. 9, 1045-1053 68. Deierlein, G. G., Noguchi, H. (2003). “Overview of US-Japan Research on the Seismic Design of Composite Reinforced Concrete and Steel Moment Frame Structures,” Journal of Structural Engineering, ASCE, Vol. 130, No. 2, pp. 361-367; 69. Chen, C-H, Lai, W-C, Cordova, P., Deierlein, G. G., Tsai, K-C (2004). “Pseudo-dynamic Testing of a Full-Scale RCS Frame: Parts 1 and 2,” Proc. 13th WCEE, Vancouver, Canada, Papers 674 and 2178. 70. Tong, X., Hajjar, J. F., Schultz, A. E., and Shield, C. K. (2005). “Cyclic Behavior of Composite Steel Frame-Reinforced Concrete Infill Wall Structural System,” Journal of Constructional Steel Research, Vol. 61, No. 4, pp. 531-552. E-4 71. Saari, W., Hajjar, J. F., Schultz, A. E., and Shield, C. K. (2004). “Behavior of Shear Studs in Steel Frames with Reinforced Concrete Infill Walls,” Journal of Constructional Steel Research, Vol. 60, No. 10, pp. 1453-1480. 72. Rassati, G. A., Hajjar, J. F., Schultz, A. E., and Shield, C. K. (2003). “Cyclic Analysis of PR Steel Frames with Composite Reinforced Concrete Infill Walls,” Proceedings of Advances in Structures: Steel, Composite and Aluminum (ASSCA) ’03, Sydney, Australia, June 23-25, 2003, Association for International Cooperation and Research in Steel-Concrete Composite Structures, Sydney, Australia, pp. 1259-1265. 73. Hajjar, J. F., Tong, X., Schultz, A. E., Shield, C. K., and Saari, W. K. (2002). “Cyclic Behavior of Steel Frames with Composite Reinforced Concrete Infill Walls,” Composite Construction in Steel and Concrete IV, Hajjar, J. F., Hosain, M., Easterling, W. S., and Shahrooz, B. M. (eds.), United Engineering Foundation, American Society of Civil Engineers, Reston, VA, 983-994. 74. Tong, X., Hajjar, J. F., Schultz, A. E., and Shield, C. K. (2002). “Cyclic Behavior of Composite Steel Frame-Reinforced Concrete Infill Wall Structural System,” Performance of Structures – from Research to Design, Proceedings of the American Society of Civil Engineers Structures Congress ’02, Denver, Colorado, April 4-6, 2002, ASCE, Reston, VA, pp. 269-270. 75. Schultz, A. E., Hajjar, J. F., Shield, C. K., Saari, W. K., and Tong, X. (2000). “Study of the Cyclic Interaction In Steel Frames with Composite RC Infill Walls,” Paper No. 2727, Proceedings of the Twelfth World Congress on Earthquake Engineering, Auckland, New Zealand, January 30-February 4, 2000, New Zealand Society of Earthquake Engineering, Auckland, New Zealand. 76. Schultz, A. E., Hajjar, J. F., Shield, C. K., Saari, W., and Tong, X. (1998). “RC Infills in Steel Frames as Composite Systems for Seismic Resistance,” Paper No. T186-2, Proceedings of the First Structural Engineers World Congress, San Francisco, California, July 19-23, 1998, Elsevier Science Ltd., Oxford, U.K. 77. Ibarra, L.F., Medina, R.A., and Krawinkler, H. (2005). “Hysteretic Models that Incorporate Strength and Stiffness Deterioration” accepted for publication to International Journal for Earthquake Engineering and Structural Dynamics. 78. Medina, R.A., and Krawinkler, H. (2005). “Evaluation of Drift Demands for the Seismic Performance Assessment of Frames,” accepted for publication in Journal of Structural Engineering, ASCE. 79. Medina, R.A., and Krawinkler, H. (2005). "Strength Demand Issues Relevant for the Seismic Design of Moment-Resisting Frames", accepted for publication in Earthquake Spectra. 80. Ibarra, L.F., and Krawinkler, H. (2004). “Global Collapse of Deteriorating MDOF Systems,” Proceedings of the 13th World Conference on Earthquake Engineering, Paper #116, Vancouver, Canada. 81. Medina, R.A., and Krawinkler, H. (2004). “Influence of Hysteretic Behavior on the Nonlinear Response of Frame Structures,” Proceedings of the 13th World Conference on Earthquake Engineering, Paper #239, Vancouver, Canada. 82. Adam, C., Ibarra, L.F., and Krawinkler, H. (2004). “Evaluation of P-Delta Effects in NonDeteriorating MDOF Structures from Equivalent SDOF Systems,” Proceedings of the 13th World Conference on Earthquake Engineering, Paper #3407, Vancouver, Canada. 83. Krawinkler, H. (2004). “Exercising Performance-Based Earthquake Engineering,” Proceedings of the 3rd International Conference on Earthquake Engineering, Nanjing, China, Oct. 18-20, 2004, pp. 212218. 84. Krawinkler, H., and Ibarra, L. (2004). “Sidesway Collapse of Frames with Deteriorating Properties,” Proceedings of the 2004 SEAOC Convention, Structural Engineers Association of California, Sacramento, August 25-28, 2004, pp. 239-250. E-5 PROPOSAL TO THE U.S. NATIONAL SCIENCE FOUNDATION “NEESR-SG: Controlled Rocking of Steel-Framed Buildings with Replaceable Energy Dissipating Fuses” Submitted for review to: NSF NEES-Research Program on March 11, 2005 REVISED JULY 18, 2005 Principal Investigator: Gregory G. Deierlein, Stanford University (lead organization) Co-Principal Investigators: Sarah Billington, Stanford University Jerome Hajjar, University of Illinois Senior Research Personnel: Helmut Krawinkler, Stanford University Mitsumasa Midorikawa, Building Research Institute (Japan) E-Defense Liaison: Masayoshi Nakashima, E-Defense (Japan) NOTE – This document includes excerpts of the proposal necessary for the NEES compliance check. Since the time that the proposal was submitted, one of the co-PI’s (Hajjar) has moved from the University of Minnesota to the University of Illinois. In conjunction with this move, we are proposing to move some of the testing from the Minnesota-NEES (MAST) to Illinois-NEES. We have modified the plan based on the new testing location; however, there may be some remnant references to the MAST facility in this write-up. These references should be interpreted as now pertaining to Illinois-NEES. Additionally, to accommodate the reduced budget, the research plan will primarily focus on inelastic fuses consisting of HPFRCC panels. Alternative fuses, such as the Buckling Restrained Braces (BRB) which were envisioned in the original proposal will still be considered in the analysis study. However, the extent to which these will be tested in the physical experiments will depend on soliciting donations of pre-qualified BRB dissipation devices from industry sources in the US and Japan. CONFIDENTIAL – NOT FOR DISTRIBUTION D-1 D. PROJECT DESCRIPTION D.1 - Project Participants Table 1. Project Participants Name and Title Gregory G. Deierlein Professor Affiliation Stanford University Principal Investigator Sarah Billington Assoc. Prof. Stanford University Co-Principal Investigator Jerome F. Hajjar, Professor University of Illinois Expertise Role in Project Research management, performance-based earthquake engineering, nonlinear analysis, design of steel and composite steel-concrete structures, development of building code provisions. Design and behavior of structural concrete and HPFRCC materials and systems, computational modeling of cementitious composites. Large-scale structural testing ; nonlinear structural analysis and design; performance-based earthquake engineering. Co-Principal Investigator Helmut Krawinkler Professor Stanford University Performance-based earthquake engineering assessment and design, experimental and analytical simulations. Building Research Institute (Japan) Seismic design and behavior of steel structures, large-scale testing and shake table simulations, Japanese building code standards Other Senior Personnel Mitsumasa Midorikawa Research Coordinator of Building Technology Other Senior Personnel D-2 Project coordination (PI); schematic design and planning of building systems; planning and design of shake table test at EDefense, coordination of education and outreach activities. Planning, design, modeling and testing of HPFRCC shear dissipation panels, collaboration on system test at NEES Illinois and E-Defense; summer REU advising. Planning, design and execution of medium- and large-scale quasistatic system tests; data archiving and curation to NEES repository; project website; education and outreach activities. Design and seismic performance assessment of rocking wall systems, building system studies, coordination of wall-frame system test at E-Defense and large-scale test at Illinois. Project coordination of Japanese collaborators, development of braced-frame rocking systems following Japanese construction practice, planning and design of shake table test at E-Defense. Time Commitment (mos./year) 2-2-2-2 0.75-0.75-075 0.5-0.75-0.750.5 0.5-0.750.5 1-1-1-1 D.2 - Utilization of NEES Equipment Resources, E-Defense and Stanford Experimental Facilities Major testing will be conducted at the University of llinois-NEES facility and the E-Defense shake table in Japan. In addition, material and small component testing will be conducted in the structural engineering laboratory at Stanford University. Table 2 shows the planned occupation at each site. Table 2. Scheduling for NEES and Major Equipment Site Usage (* = 1 month) Site 10/1/05 – 9/30/06 10/1/06 – 9/30/07 *** N-Illinois *** *** *** *** *** *** 10/1/08 – 9/30/09 *** *** E-Defense Stanford 10/1/07 – 9/30/08 *** *** *** NEES Illinois Laboratory: The Illinois system will be used to conduct the large-scale quasi-static cyclic tests of the controlled rocking structural systems investigated in this research. These tests will characterize the progressive damage and inelastic response of the structure and will validate the qualities of the system. The proposed testing entails the use of two multi-axial testing boxes mounted on the strong wall, in addition to high-resolution data acquisition systems for measurement and archiving of loads, displacements, strains, and video images. E-Defense Shake Table: The large 15 x 20 m shake table at the E-Defense facility in Japan will be used to conduct dynamic tests of a large (near full-scale) building system with a hybrid rocking bracedmoment frame system with structural fuses. The E-Defense shake table is required to accommodate the large-scale testing which is critical to investigate the energy dissipating fuse mechanisms and the hybrid braced-moment frame system at a realistic scale. The large scale is necessary to accurately simulate the behavior, which is necessary both from a scientific point of view (accurate representation and understanding of the behavior) and to demonstrate the validity of the new rocking fuse system to engineers and other stakeholders. Apart from its large size, the E-Defense facility provides other benefits. The lab is developing an inertial system to apply gravity loads and seismic mass in multi-story building models. This inertial frame will simplify the shake table test setup and make the test more economical. Another benefit is that this proposed project will leverage financial and intellectual resources of a companion Japanese project that will be funded by the Japanese government (see supporting letter from Dr. Nakashima, Director of E-Defense). STANFORD Structural Engineering and Materials Lab: The Structural Engineering and Materials Lab at Stanford University has a strong floor and several loading frames that can be used for development testing of the shear panel fuses. The laboratory is equipped with loading actuators, measurement transducers, and data acquisition systems. The lab also houses equipment for fabrication, curing and testing of high performance fiber reinforced cementitious composite (HPFRCC) materials. For materials testing there are two MTS testing machines; one is an 89 kN (tension/compression), fatigue rated machine with hydraulic grips, the second is a 245 kN (tension/compression), fatigue rated machine with a 1 x 2 meter loading table. This facility has access to the high-speed Internet-2 and can be used for internet-based collaboration (e.g. telepresence) and NEES data archiving for this project. D-3 EXCERPTS FROM PROPOSAL RELATED TO NEES-ILLINOIS TESTS Proposed Braced-Frame Fuse System: As illustrated in Fig. 1, the proposed research focus is on the development of a seismic force resisting system that combines desirable aspects of conventional steelbraced framing (or equally valid, of reinforced concrete walls) with two alternative and complementary fuse concepts – shear panel fuses and axial column fuses. The framing configurations shown are two examples of possible variants that can be envisioned with this system. The underlying concept of the system utilizes controlled rocking (pivoting) and a capacity design approach to concentrate inelastic deformations in the fuse components. The configuration of Fig. 1a demonstrates the application of a shear panel fuse, where energy is dissipated through the large shear strains developed across the shear panel between the braced frames. For a given story drift, the magnitude of shear strain energy dissipated in the panel is proportional to the ratio of the dimensions of the braced panel to the shear panel, i.e., the dimensions B/A shown in Fig. 1a. Thus, by altering the geometry, one can achieve large amplifications in shear deformations, whereby large amounts of energy can be dissipated at low drifts. Ideally, the shear panels should have a large elastic stiffness, a well defined yield point, and large energy dissipation capacity. Two materials that will be investigated for the shear panels are high-performance fiber reinforced cementitious composites (HPFRCC) and low-yield steel plates. The panels are connected to the frame with bolts (or dowels) and are designed for easy access and replacement. This is in contrast to conventional systems, such as eccentrically braced steel frames or coupled shear walls, where the shear links are integral with the structural system and difficult to repair once they Figure 1 – Pivoting Braced Frame (a) single bent with shear are damaged. Likewise, the inelastic dissipating panels, (b) dual bent with shear dissipating panels and hinge regions of moment frames are axial dissipating strut integral to the structural frame and difficult to repair. The configuration shown in Fig. 1b demonstrates the use of axial column fuses, which can either be designed to work on their own or in combination with the shear dissipation panels. The axial deformations of a fuse are related to the bay width by the ratio of bracing panel width to story height (A/H). One way to implement the axial column fuses is through the use of buckling-restrained columns (BRCs), similar in concept to buckling-restrained braces (BRBs) that have been successfully introduced into design practice over the past ten years [1]. Like their BRB counterparts, the BRCs would be designed to dissipate energy through large inelastic deformations of a steel core, which is prevented from buckling by some type of housing (often a steel tube filled with concrete). Another candidate for the axial column fuse is a yielding base plate, such as Midorikawa et al. [2] have studied. The configuration of Fig. 1b demonstrates where it may be advantageous to employ both axial column and shear panel fuses, so as to improve response or redundancy of the systems. D-4 For optimal building performance, the fused bracing systems (Fig. 1) are intended for use with a parallel system that provides an elastic restoring force. As suggested by the framing plan in Fig. 2, we envision that the parallel system to be a flexible moment resisting steel frame. The combination of the stiff fused braced frame and the flexible frame offers several advantages over conventional systems or either system acting alone. By balancing the strength, stiffness, and inelastic deformation characteristics of the two systems, the goal is for the moment frame to remain essentially elastic under the design earthquake, thereby providing a restoring force that will reduce (or even eliminate) residual drifts. This is in contrast to conventional dual systems, where both systems are expected to deform inelastically and their interaction is unknown. After large earthquakes, when the fuses may be damaged, the moment frame will stabilize the system while the fuses are removed and replaced. Figure 2 – Schematic framing plan for hybrid system: energy dissipating braced frames with elastic moment frames NEES/E-Defense Collaboration: The proposed research will be an international collaboration between US and Japanese participants and will utilize the NEES Illinois and the E-Defense facilities. With one of the key objectives being to validate the proposed system for use in engineering practice, the E-Defense facility provides the unique capabilities to perform dynamic shake table tests of a nearly full-scale building prototype. The research topic is of mutual interest to the Japanese researchers and industry. A team under the leadership of Dr. Midorikawa (Research Coordinator of Building Technology at the Japanese Building Research Institute) has been identified; and, as indicated in the attached letter from Dr. Nakashima (Director of E-Defense), funding for Japanese collaborators has been secured. The co-PI’s have a long history of collaboration with Japanese researchers, and over the course of developing this proposal we have corresponded extensively with Dr. Nakashima and Dr. Midorikawa. They both are enthusiastic about collaborating with us on this project, and we have included Midorikawa as a co-leader to direct the proposed collaborative testing at the E-Defense facility. Should this proposed be funded, we also expect that the Japanese will become involved in the proposed testing at the NEES Illinois facility and send visiting researchers to the U.S. D.6 Strategic Research Plan As illustrated in Fig. 11, the research plan is organized around a central spine of activities that integrate the data and results of the experimental simulations into a coherent systems design approach, culminating in the development of design implications and recommendations for the new structural framing systems. The details associated with each task are described later in sub-sections of Section 7.1. Briefly, the main features of the plan are the following: Task 1 – Schematic Design of Prototype Systems: Much like in engineering design practice, the research will begin with a detailed schematic design effort to articulate and quantify the important issues and parameters for the subsequent experimental and analytical studies. Performance-based design thinking will guide this effort with consideration given to life-cycle and post-earthquake repair costs. D-5 Task 2- Computational Simulation: As schematic designs are developed, computational models will be created and tested to simulate the nonlinear seismic response of the structures. Included will be development of models to simulate unique features of the rocking behavior and inelastic fuses, utilizing existing data on low-yield and BRB steels (from previous research) and HPRFCC panels (obtained from Task 3). Task 3 – Characterization and Design of HPFRCC Panels: Guided by sizing and performance parameters identified through the schematic design effort of Task 1, this task will focus on the development of HPRFCC panels. Data from HPRFCC material and panel testFigure 11 – Strategic Research Plan ing and computational modeling will provide input to characterize the panels response in the macro-simulations (Task 2) and large-scale validation tests at Illinois (Task 4). A complementary effort (upper right box of Fig. 11) will synthesize data on BRBs and low-yield strength steel for energy dissipation. Task 4 – Development and Large-Scale Validation of Energy Dissipating Rocking Frames (NEESIllinois): This task integrates data from the schematic designs, computational simulation results, HPFRCC shear panel study (Tasks 1 to 3) and low-steel shear panel, to design and test the rocking braced frame subassembly and fuses. Quasi-static tests will be conducted at large scale in the Illinois facility, with the primary goals to (a) characterize the shear panel and axial column fuses, and (b) validate that the system and components (e.g., the brace pivot) work as intended. Task 5 – Parametric Design and Performance Evaluation of Building Systems: Building upon the schematic designs (of Task 1), the simulation models (Task 2), and the experimental simulation data (Tasks 3 and 4), the parametric design studies pull together the information to conceive and assess a number of alternative designs. One outcome of this task will be data to plan and design the shake table specimens to be evaluated at E-Defense (Task 6). The other outcome will be information feeding into the design implications and recommendations of Task 7. Task 6: Large-Scale Shake Table Simulation (E-Defense): Data, models and knowledge gained from Tasks 1-6 will be synthesized and validated through the planning, design and simulation testing of a large-scale frame on the E-Defense shake table. The frame will be designed as a test bed to permit simulation of alternative fuse concepts and will be a focal point of US-Japan research collaboration. Task 7 – Design Implications and Recommendations: The data and information collected and made accessible through NEES-grid will provide a unique opportunity to accelerate research dissemination on rocking braced systems with fuses into engineering practice. Design implications and recommendations will be developed with the participation of professional engineering organizations. D-6 D6.1 Detailed Project Tasks TASK 3 – TESTING AT STANFORD UNIVERSITY Task 3: Characterization and Design of HPFRCC Energy Dissipating Shear Panels -- To develop the energy-dissipating shear panels for the large-scale rocking braced frame tests will require two main research tasks: (1) Finite element (FE) modeling to identify optimal HPFRCC properties and their combination with steel reinforcement, and (2) Reduced-scale panel testing to evaluate panel properties and verify connection detail behavior. FE modeling will be used to identify the trade-offs of stiffness, strength and energy dissipation with various materials and reinforcement details. For instance, as the percentage of fine aggregate in HPFRCC is increased, A the stiffness will increase but the ductility will decrease, thus reducing the ability of the HPFRCCsteel combination to dissipate significant hysteretic energy. The finite element modeling will build upon recent research on modeling HPFRCC HPFRCC Shear Panel materials under cyclic loading [40, 41, 44, 65, 66], including rate dependent tests on HPFRCC that are currently underway at Stanford. Based on the finite element modeling, various combinations of reinforcement and HPFRCC mix design will be A-A A investigated under quasi-static cyclic shear loading Figure 12 Shear panel test set-up to verify strength, stiffness, ductility and damage to the shear panels. The reduced-scale panels will be tested as shown in Fig. 12. The experiments will also serve to validate again the robustness of the bolted connections. A sandwich panel design using HPFRCC will also be investigated for potential advantages in reduced damage and ease of replacement. TASK 4 – TESTING AT ILLINOIS-NEES Task 4: Development and Large Scale Validation of Energy Dissipating Rocking Braced Frame Components (Illinois-NEES) -- A series of experiments will be conducted in the Illinois Laboratory to investigate the cyclic performance of the braced-frame rocking system and components. Figure 13 shows a typical configuration of the test specimen for a braced frame system with HPFRCC shear panels, lowyield steel shear panels, and structural pivots at the base of the system. The dimensions will reflect those of the braced bent in the lower stories of the prototype structures studied in Task 1, modeled at approximately one-third to one-half scale. This setup will permit testing of several configurations of HPFRCC shear panels, the low-yield steel shear panels, the pivots at the base connections, and the connections of these components to the braced frame. The top of the frame will be attached through pinned fixtures to the NEES Loading and Boundary Condition Boxes for each individual braced frame to permit more independent motion of each frame. Quasi-static loading will be primary in-plane (including gravity loading) with modest out-of-plane (orbital) loading to simulate the realistic loads and deformations that would be experienced in a real building. D-7 The purpose of these tests is to document the progressive inelastic response and damage in the complete rocking system, with a primary focus on assessing the detailed response and robustness of the fuses, the pivot assembly of the braced frames, and the connections of the fuses (both the HPFRCC and lowyield steel shear panel fuses) to the braced frames. To the extent permitted by the budget or otherwise made available through industry donations, vertical Buckling Restraint Column (BRC) fuses will also be investigated. Because the energy dissipating fuses are replaceable, several tests will be conducted using the braced frame system. The specimens will be heavily instrumented so as to provide comprehensive information for Task 7 on performance-based design of this structural system. We would like to explore use of the Close-Range Digital Photogrammetric System (or other optical methods) to document both the rocking component of the motion and the shearing response of the HPFRCC and/or lowyield steel panels. Figure 13. Schematic Test Specimen of Steel Braced Frame with Replaceable Energy Dissipating Devices for Illinois Laboratory Telepresence: The Illinois-NEES Laboratory provides premier capabilities for remote teleparticipation for the other project participants, including those in Japan. Teleobservation will be achieved through a set of remotely-controllable digital video and still image cameras spaced around the perimeter of the specimen, and through an array of sensors (e.g., strain gages, displacement sensors, and rotation sensors). It is envisioned that the project participants will work as a team during the experiments to study the response and make decisions about the appropriate loading protocols. This is critical for this project, as it permits the contributions of each researcher to this project to be brought to bear on the execution of these pivotal tests. All sensor, video, audio, and still image information is streamed out over Internet2 for both private clients (i.e., project participants and other interested researchers) and public clients. Task 5: Parametric Design and Performance Assessment of Energy Dissipating Rocking Braced Frame System -- Performance evaluation of the complete structural system is a key aspect of the proposed research. The performance evaluation will be conducted using the basic framework methodology, originally developed within the PEER Center and now being translated into design guidelines through the ATC 58 effort. The primary engineering performance metrics will be those related to reparability (as inferred from residual drifts and damage accumulation in the fuses) and safety (as inferred through the mean annual frequency of collapse). The engineering demand parameters (EDPs) will be processed through fragility (loss) curves to determine generalized decision variables, such as annualized losses to structural and nonstructural systems and building content. A matrix of performance criteria will be established, which will serve as the basis for an objective evaluation of various design options, including conventional braced frame and moment frame designs and appropriate energy dissipating rocking systems. The performance will be evaluated using incremented nonlinear time history analyses using the OpenSees platform, including statistical evaluation of response data at various levels of intensity. The variables that will receive attention in this parametric design and performance evaluation include: • • • • Building configuration variables, such as plan size and number of stories Relative strength and stiffness of energy dissipating braced frame and elastic moment frame Systems with alternative fuse types and configurations, including single versus multiple fuses Ground motion variables (intensity, frequency content, near-fault effects, etc.) D-8 Task 6: Large Scale Validation of Energy Dissipating Rocking Braced Frame System (E-Defense) -The large-scale frame tests planned for the E-Defense shake table in Japan will integrate the results from Tasks 1 to 5 and serves as a focal point to facilitate international research collaboration. The shake table simulations, representing salient features of the complete structural system, will provide unprecedented understanding of the interactive effects of braced frame rocking, energy dissipative fuses, and the elastic restoring frame system. Conducting the tests at full-scale (or near full-scale) is important to accurately represent the interactive behavioral effects of components and systems in the structural frame, the fuses and their connections to the frame, and the slab/concrete floor deck. Our schematic design for the fourstory test frame (see Fig. 14) is configured to provide a versatile test-bed that can be used to evaluate multiple types of fuse dissipaters. Aside from its large size and capacity, the E-Defense facility is developing an innovative inertial mass system, which will dramatically simplify and reduce the cost of the shake table test. As one of the important outcomes of the large-scale test is validation of our computational simulation models, detailed response prediction analyses will be conducted prior to testing (using OpenSees) and we will encourage outside researchers to make blind predictions of the response. The E-Defense facility is uniquely suited to perform this ultimate validation test. It is the only one available, worldwide, that permits close-to-full-scale shake table testing of a comprehensive assembly that replicates all important interactions taking place between all the components of a complete structure. Such a validation test cannot be accomplished elsewhere, and it comes at a small cost because of the great interest and extensive complementary efforts of the Japanese project collaborators. Figure 14. Schematic Steel Frame Specimen for E-Defense Shake Table Test D6.2 Project Implementation Team Organization, Management Plan, and Schedule: The project leadership team is diverse; led by a PI from a non-NEES equipment site, with co-PI’s from both NEES and non-NEES sites; faculty are at different stages in their careers, of different genders, and with different specialties (structural materials, computational simulation, and earthquake engineering); our external advisory board of practicing structural engineers will have strong input; and our Japanese collaborator is assembling a complementary research team in Japan. The organizational chart for our project is shown in Fig. 15. The management is divided between four major initiatives, three of which encompass the major research task, with the fourth being education and outreach (described in Sec. D.7). All the investigators and students will work integrally on the project, with each of the co-PI’s having a lead responsibility in one of the major thrusts. Within each initiative are specific sub-tasks, which are the primary responsibility of the individuals listed. The project will support three PhD students, each of whom will have the lead role on one component of the research with supporting roles on other tasks. A functional budget for the overall project is provide D-9 in Sec. D6.5, which is supplemented by further details in the full budgets and budget justifications presented later. The schedule of the proposed tasks (as described in the previous section) is summarized in Table 3. During the development of this proposal, the co-PI’s have solicited input from practicing engineers and developed effective working relationships, which they look forward to continuing throughout the project. Input from a group of practicing structural engineers and building constructors will be formalized through the creation of an external advisory board to whom the co-PI’s will provide with periodic updates and meet with annually. The co-PI’s are already making regular use of commercial teleconference and webmeeting facilities, and they look forward to utilizing the enhanced collaboration technologies offered through the NEESgrid. Interaction between the co-PI’s and sites is expected to be an on-going activity, with formally scheduled web-meetings occurring at least once per quarter over the course of the project, with at least one in-person meeting each year. Risk Mitigation: All of the coPI’s and senior personnel have experience with large projects involving multiple organizations, large-scale testing, and international collaboration. As such, they appreciate the challenges and risks to successful completion of the project. Details of a formal risk management plan will be established upon the project award. Briefly, our Figure 15 – Project Management Organization primary strategy for risk mitigation will be through (a) careful planning of the research activities, (b) paying careful attention to activities that can be impacted by external factors (e.g., lab delays) and are on the critical path, (c) continuous monitoring of our own progress, and (d) effective communication with team members, equipment sites, NEESinc, contractors, and others whose work progress will affect the overall project schedule. Budgeting of large tests is another concern. We have been in contact with the Illinois-NEES and E-Defense facilities, and we think we have an accurate assessment of the testing expenses built into our budget. In the event of unforeseen cost over-runs (e.g., larger than expected bids from contractors to build the specimens) we do have contingency plans to reduce test specimen sizes and modify the testing scope if necessary. Use of NEESGrid Resources: NEESgrid resources are integrated into this research and education plan in four fundamental ways: • Telepresence activities as discussed in Task 4 (with similar expectations for Task 6 at E-Defense) Table 3 - Timing and Scheduling of Research Tasks Proposed Task Task 1 – Schematic Designs Task 2 – Comp. simulations Task 3 – HPFRCC Panels Task 4 – Braced Bent w/Fuses Task 5 – Parametric Designs Task 6 – Braced Frame w/Fuses Task 7 – Design implications Report and Paper Publication 10/05 – 3/06 ****** *** ****** 4/06 – 9/06 ** ****** ****** *** *** D-10 10/06 – 3/07 ** ****** ****** ****** ****** ** 4/07 – 9/07 Dates 10/07 – 3/08 ** ****** ****** ****** *** ** ****** ****** ****** ****** ** ** 4/08 – 9/08 10/08 – 3/09 ** ** ****** ** ** ****** ****** ** ****** ****** ** 4/09 – 9/09 ***** ****** ****** • • • Data sharing and archiving plans as discussed in Section D.6.3 Education and outreach plans, specifically through the establishment of a public telepresence website as discussed in Section D.7 Extensive utilization and model development for the OpenSees platform [Tasks 2, 5], which has been adopted as part of NEESGrid. D6.3 Data Sharing and Archiving Plan and Dissemination to Earthquake Engineering Community The NEES-Illinois Laboratory provides outstanding facilities related to archiving of all sensor data (including resistance strain sensors, displacement and rotation sensors, and optical deformation data, video and audio data, and still image data. This data is synchronized and archived on site at the NEES Laboratory during the experiment. Subsequent to the test, curation of the data to the NEES national data repository is enabled with assistance from the NEES Laboratory staff. The investigators have been leaders in advising on the establishment of data models and policies for data curation within NEES (Hajjar sits on both the NEES Information Technology Committee and the NEES Data Sharing and Archiving Committee; Deierlein and Krawinkler are on the NEES Board of Directors, which has reviewed and approved these policies). It is our intent that this project serve as a model for data curation, data sharing, and documentation of the research. Prior to conducting any experiments or substantial analyses as part of this project, we will work with our students and the staff at NEES-Illinois, E-Defense, and NEESit to (1) establish key elements of data and metadata for timely and comprehensive data documentation and curation, and (2) develop algorithms for data analysis and processing, such that processed test data can be viewed and compared to analytical simulations during the tests. These steps will help ensure that the data and metadata is posted to the NEES national data repository, consistent with the policies of the NEES Consortium, Inc. We are committed to the NEES policy of uploading and releasing the processed data to the NEES national data as soon as practically possible, and certainly within the maximum timeframe specified in the data policies set by the NEES Board. Staff and student time at the equipment sites have been budgeted for this effort. A similar archiving of OpenSees data will be executed for all significant structural analyses conducted in this research. D6.4 Payload Projects Payload projects provide excellent opportunities for leveraging the proposed work and for broadening participation. We will actively encourage other researchers, particularly younger faculty and faculty from underrepresented groups, to collaborate. Possible payload projects for this research include: (1) Investigating alternative fuse designs, by re-using the rocking braced frame specimens at the Illinois or EDefense facilities; (2) Developing alternative column rocking base connections through additional testing on the Illinois specimen; (3) Exploring new technologies for recording and interpreting three-dimensional measurements (e.g., laser-based displacement measuring devices); and (4) detailed 3D continuum modeling to complement testing and macro-analysis to be performed in this project. D6.5 Functional Budget The functional budget of Table 4 provides a breakdown of the allocation of resources between the various categories of research, education/outreach, and data archiving/sharing. All of the figures include indirect charges (i.e., gross charges) and reflect the personnel and other supporting costs associated with each activity. So, for example, in addition to the direct costs of the frame test specimen, the funding allocation to the E-Defense testing includes the portion of salary and travel costs associated with the co-PI and graduate students for time spent planning and conducting the frame test at E-Defense. Specimen Disposal: Budgets for testing include costs for specimen disposal at the Illinois and E-Defense facilities (see detailed budget justifications). D-11 Table 4 - Functional Budget (Total $) ITEM Experimental Research Stanford NEES-Illinois E-Defense Non-Experimental Education and Outreach Data Archiving/Sharing TOTAL Year 1 Year 2 Year 3 Year 4 62,000 49,000 34,000 41,000 25,000 12,000 223,000 44,000 151,000 129,000 54,000 26,000 26,000 430,000 0 70,000 190,000 84,000 27,000 27,000 398,000 0 12,000 78,000 43,000 28,000 28,000 189,000 Cumulative 106,000 282,000 431,000 222,000 106,000 93,000 124,0000 D.7 Education, Outreach, and Training As indicated in the management organization chart (Fig. 15), plans for education and outreach contribute significantly to project plans. Three major education and outreach components are planned for the project: (1) project website and public teleparticipation, (2) research involvement for undergraduate students, and (3) research involvement for graduate students. Creating opportunities for students from under-represented minority groups is emphasized throughout the plan by leveraging associations with existing programs and initiatives at the participating universities, the participating NEES site, and the Pacific Earthquake Engineering Research (PEER) Center - the latter being facilitated by three of the coPI’s (Deierlein, Krawinkler, and Billington) involvement in PEER’s research and education programs (see http://peer.ucsd.edu/). All activities will be coordinated and linked with the NEES Consortium education and outreach activities. Website and Teleparticipation: A project website will be created to promote research collaboration among the research team and outreach to other researchers, students, and the public. The site will provide a schedule of testing, with links to teleparticipation resources at the Illinois NEES and E-Defense sites to permit observation of the test and test data as it is being generated through the public client teleparticipation interface. This project-specific website for public telepresence will include content about the research status (particularly ongoing experimental testing) targeted for four different age levels (e.g., primary school, secondary school, the general population and the primary target audience of undergraduates in all fields). Involvement of Undergraduate Students: Undergraduate students at the University of Illinois will be involved on an ongoing basis as laboratory assistants at the NEES site. Beyond this, the project has targeted plans for participation of under-represented minority groups in an Earthquake Engineering Scholars Course (hosted annually by the educational program of the PEER Center) and summer research internships at one or more of the sites. Funding has been allocated to involve undergraduate summer intern students during each year of the project. Addition funds to support one or two undergraduates from Stanford are likely to be available through a program supported by the Stanford Vice Provost for Undergraduate Education. Student recruitment will be done through existing mechanisms of the Engineering Diversity Program (http://emp.stanford.edu/EDP/) at Stanford University, the PEER Educational Affiliate Program, recruiting visits by the co-PIs to selected schools with large under-represented minorities. Involvement of Graduate Students: This project will provide research support for three PhD students. Our goal is for at least one of these students to be from an under-represented minority group. The co-PI’s are committed to actively recruiting diversity students, through the undergraduate programs described above and through programs offered by the Stanford School of Engineering Diversity Programs (http://soe.stanford.edu/edp/home/index.html), which has dedicated fellowship funding for graduate students from under-represented minorities. D-12
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