JLBG (Jurnal Lingkungan dan Bencana Geologi) (Journal of Environment and Geological Hazards)
Vol 11, No 1 (2020)

Groundwater Fluctuation Simulation in Pagelaran Landslide, Cianjur, Indonesia

Twin Hosea Widodo Kristyanto (Geology Study Program, FMIPA, Universitas Indonesia
Institute of Applied Geology, National Central University, Taiwan)

Asriza Asriza (Program Studi Geologi, FMIPA UI, Universitas Indonesia Kampus UI Depok, Kota Depok, 16424, Indonesia)
R. Syahputra (Program Studi Geologi, FMIPA UI, Universitas Indonesia Kampus UI Depok, Kota Depok, 16424, Indonesia)
Join Wan C. Sigalingging (Division of database Center, Meteorological, Climatological, and Geophysical Agency, Indonesia Jalan Angkasa I, No.2 Kemayoran, Jakarta Pusat 10720)
Tito L. Indra (Program StudiGeofisika, FMIPA UI, Universitas Indonesia Kampus UI Depok, Kota Depok, 16424, Indonesia)



Article Info

Publish Date
28 May 2020

Abstract

Pagelaran is one of area in Southern Part of Cianjur. This area has high susceptibility of landslide. One of landslide in Pagelaran, which happened on December 2014, has destroyed 13 houses and damaged vital road along 200 m. A year later, it started to conduct observation regarding the slope. The research aimed to know the role of groundwater level fluctuation in Pagelaran Landslide. The geometry of slope and its slip surface were determined using Electrical Resistivity Tomography. The actual groundwater level was determined by measuring it from surrounding artesian wells. Parameters angle of friction, cohesion, and unit weight were obtained from laboratory tests toward undisturbed soil samples. These data were used for analyzing the actual slope stability condition. Then it was conducted the simulation of slope stability in accordance with fluctuations of groundwater level. The simulation was done by raising the groundwater level with range of 0.5 m. The results showed that the actual slope stability was in critical condition with the value of safety factor 1.044. It also showed that slope stability waned as rising of groundwater level. The value of safety factor was reduced by an average of 0.034 in each 0.5 m up of groundwater level until it became failure (FS<1) when the groundwater level was 0.95 m above the actual position. Therefore, it can be concluded that the position of groundwater level played a role toward the stability of slope in Pagelaran. The rising 0.5 m of groundwater level position will reduce the slope safety factor by 0.034. The slope will become failure if the position of groundwater level rises by 0.95 meter from the actual position. To prevent the rising of groundwater level in rainy season, which can trigger landslide, it can be attached pipes along the slope body to flow the groundwater through them.

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Journal Info

Abbrev

jlbg

Publisher

Subject

Earth & Planetary Sciences Environmental Science

Description

Jurnal Lingkungan dan Bencana Geologi (JLBG) merupakan terbitan berkala Pusat Air Tanah dan Geologi Tata Lingkungan, yang terbit triwulan (tiga nomor) dalam setahun sejak tahun 2010. Bulan terbit setiap tahunnya adalah bulan April, Agustus dan Desember. JLBG telah terakreditasi LIPI dengan nomor ...