Simulasi Desain Teras dan Analisis Stabilitas Lereng untuk Konservasi Tanah dan Air

Abstract

Simulation of Slope Stability Analysis and Terrace Design for Water and Soil Conservation

ABSTRACT. The terrace development for soil and water conservation often experience the failure such as landslide, like some agriculture farm in Sub-District Banjarwangi, regency of Garut. Considering this problem, it is required to conduct research and analysis on slope stability, especially for the slope with bench terrace. Slope stability is determined by the slope morphology, soil physically and mechanical properties. This research aims to determined the slope stability at a farmland made by terrace, and expected to give recommendation for planning water and soil conservation to avoid landslide. This research was to conducted in field, laboratory and with computer simulation. The triaxial test of soil taken I Mulyajaya village, Sub-District of Banjarwangi shows that at the mean density of 1.44 t m^-3, the average effective cohesion is 0.15 kgf cm^-2 and the average internal friction angel is 20.3⁰ for natural condition. Actual terrace at the landslide location is initially stable (Fs = 1.22) and become unstable (Fs = 0.31) as the soil is nearly saturated with increase of soil water table due to rain. Simulation using the slope design software which is being developed can ease the prediction of soil stability in order to help land utilization planning for soil and water conservation.