Back Calculation of Slope Stability in Batu Gadjah, Ambon City Using the Solution of Analytical and Finite Element Method

Abstract

At the time of entering the rainy season from year to year in the Maluku region, especially the Ambon Island area experienced an increase in landslides due to rainfall, human activities such as excavation under the slopes, loss of vegetation, changes in land use and so on. The disaster that occurred on RT.03 / RW.01 Batu Gadjah Village, Sirimau Subdistrict, Ambon City, on June 1, 2018, ago, still leaves a trace of damage that until now. In this study, the researcher will analyze the slope (deformation that occurs) in the 2D model using Finite Element Method (FEM), by reviewing the weathering conditions of the rocks that are read from the results of the drill data in the form of soil properties and variations in rising groundwater levels. The results of calculations using FEM on dry slope conditions obtained the value of safety factor (FS) 1.10 and the analytical of FS value 1.18. This FS value indicates that the study area is still prone to landslides. Then the calculation with FEM on the wet slope conditions by rainwater obtained an FS value of 0.90, and analytically the FS value of 0.99. This FS value indicates that the research area has experienced a landslide.

Prevensi Gerakan Tanah Jenis Longsor Lereng di Dusun Riang Negeri Tawiri Kecamatan Teluk Ambon, Kota Ambon

“…• Untuk mengurangi gaya dorong lereng dan memperkuat gaya penahan lereng (pers.1) (Souisa et al, 2020), maka bidang lereng di potong dibuat sistem terasering (Souisa, 21 Mei 2018). Pada kaki lereng yang di potong dilakukan perkerasan dengan pengecoran.…”

Analysis of creeping avalanche velocity using physics of landslide approach

“…When the soil-rock mass (debris) is dragged by water moving along the slope, some of it transits for a moment, while others move to the foot of the slope and settle [5,6]. This is influenced by hydraulic resistance as a very important factor affecting the landslide speed.…”