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LAPORAN AKHIR TAHUN 1
PENELITIAN UNGGULAN PERGURUAN TINGGI
JUDUL
APLIKASI METODE PENYELIDIKAN TANAH NON-DESTRUCTIVE PADA LERENG
TANAH KRITIS UNTUK PENYUSUNAN PETA KERAWANAN BENCANA TANAH
LONGSOR DI RUAS JALAN BATU-PUJON
Tahun ke-1 dari rencana 2 tahun
Tim Peneliti
Ketua
: Eko Andi Suryo, ST., MT., Ph.D
(NIDN: 0023107606)
Anggota 1 : Dr. rer. nat. Ir. Arief Rachmansyah
(NIDN: 0020046606)
Anggota 2 : Dr. Eng. Indradi Wijatmiko, ST., MEng. (Prac) (NIDN: 0020028104)
Dibiayai oleh :
Direktorat Jenderal Pendidikan Tinggi,
Kementerian Pendidikan dan Kebudayaan, Melalui DIPA Universitas Brawijaya
Nomor : 023.04.2.414989/2014, Tanggal 5 Desember 2013, dan berdasarkan
SK Rektor Universitas Brawijaya Nomor 157 Tahun 2014 tanggal 10 April 2014
UNIVERSITAS BRAWIJAYA NOVEMBER
2014
RINGKASAN
Judul:
Aplikasi Metode Penyelidikan Tanah Non-Destructive pada Lereng Kritis dalam rangka Penyusunan
Peta Kerawanan Bencana Tanah Longsor di Ruas Jalan Batu – Pujon
Metode yang umum digunakan di jalan sepanjang lereng gunung adalah cutting slope yang
berpotensi menurunkan tingkat kestabilan lereng gunung tersebut. Penyelidikan terhadap safety
factor dari lereng tersebut terutama saat musim penghujan menjadi hal yang penting bagi
keselematan pengguna jalan. Hal utama yang harus diperhatikan dalam penyelidikan tanah di
lapang adalah kondisi hazard yang dapat mengancam jiwa operator pengeboran akibat kondisi
lereng kritis yang sangat tidak stabil. Oleh karena itu perlu dicari metode yang lebih aman
(tidak langsung dan tidak merusak) sebagai pengganti metode pengeboran langsung (bore-hole
wash drilling) yang selanjutnya dapat diaplikasikan dalam penyusunan Peta Kerawanan
Bencana Longsor.
Untuk menyusun metode alternatif tersebut, dilakukan penelitian dengan mengaplikasikan
metode Geofisika (Electrical Resistivity Tomography- ERT dan Ground Penetration Radar –
GPR) yang diverifikasi dengan data parameter tanah sehingga lapisan tanah di lereng kritis
tersebut dapat diinterpretasikan. Dalam studi awal, verifikasi ini dilakukan secara langsung
(dengan model lereng di laboratorium) dan secara tak langsung (dengan urugan Dam Selorejo).
Dari rumusan hubungan antara hasil ERT/GPR dengan data tanah ini, selanjutnya ERT/GPR
diaplikasikan di lereng kritis di ruas jalan Pujon dan diverifikasi secara tidak langsung dengan
menggunakan data tanah hasil bore-hole wash drilling di lokasi aman untuk mendapatkan
panduan interpretasi lapisan tanah untuk model lereng kritis. Selanjutnya, model lereng kritis
tersebut dipakai dalam analisa numeric stabilitas lereng. Dari hasil analisa numeric tersebut
dapat dikembangkan dalam bentuk peta kerawanan bencana longsor di sepanjang ruas jalan
pegunungan Pujon dengan cara mengaplikasikan ERT atau GPR di 5 lokasi lereng kritis serta
melakukan pemetaan digital dengan aplikasi GIS.
Hasil dari penelitian ini diharapkan dapat dipakai sebagai alternative metode non-destructive
field soil investigation menggunakan ERT/GPR yang bila dipadukan dengan hasil analisa
stabilitas di beberapa lokasi lereng kritis dan teknologi GIS maka dapat disusun Peta
Kerawanan Bencana Tanah Longsor di ruas jalan tersebut.
Keywords:
Longsor, ERT, GPR, Lereng Kritis, Safety Factor, Peta Kerawanan Bencana.
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