Analysis of slope stability based in the spencer method on the ring road section, Sikumana. Kupang City

Abstract

The analysis of slope stability is on of most common solution that use to answer any problems about landslide. On aplicate it, how to know the parameters that always we used on analysed slope stability is the basic way to can calculate it detail. The perameter like slope dimensions, soil sample (disturb and undisturb), and laboratory test. In this case, the slope stability is used Spencer’s Method as a of the limit equilibrium method, and in other word a a merge method of moment equilibrium (Bishop’s Method) and force equilibrium (Janbu’s Method). The soil samples are taken from the along of slope surface for 3 points, above, in the middle, and the bellow. On laboratory test we have to get the parameters like cohesi (c), friction angle (ɸ), and unit weight (γ). This analyse is to know the safety factor (Sf) value from the slope at 40 road. From the research, the slope is maked by homogeny soil, clay from the noele formation. And we can get the material properties for the samples respectly, unit weight: 16,80 kN/m3, cohesi (c): 4,88 kPa, friction angle (ɸ): 39,320 (first sample); unit weight (γ): 15,97 kN/m3, Cohesi (c): 5,08 kPa, friction angle (ɸ): 26,200 (second sample); unit weight (γ): 15,48 kN/m3, cohesi (c): 5,28 kPa, friction angle (ɸ): 26,200. And the FoS value is 0,548 base on Sencer’s Method calculate. So, is maked some slope design recommendations to get the stability condition of the slope (SF>1), are SF1=1,610; SF2=1,410.