General geology and cut-slope stability analysis of soil using slope/w at Kampung Jabir, Jeli, Kelantan.

The soil cut-slope stability analysis using Slope/W software is one of the simple methods to determine the slope stability based on the factor of safety (FOS). When the FOS value is less than one means the slope is unstable. The objective of this study was to produce a geological map of the study area with a scale of 1: 25,000 and to analyse the slope stability at study areas using the Slope/W. The lithology of the study area consists of three types of rock which is shale, granite and slate. Ages of rocks are Ordovician to Triassic, Permian to Triassic and Triassic. The alluvium is formed during Quaternary period. There are four locations that have failed slopes in the study area. The size of failed slope is in the range of small which is 28 m3, 84 m3, 71 m3 to medium that 569 m3. In order to determine the physical properties of the soil in the study area, there are three laboratory tests was conducted which is the sedimentation test, Atterberg limits tests and Vane shear test. The sedimentation test is done to determine the grain size distribution and the results shown the study area is composed of three types of soils which are fine sand, silt and clay. Atterberg limits tests have been done to determine the Liquid Limit (LL) of soil and the results shown that the soil at the cut slope is slightly plasticity, low plasticity, medium plasticity and high plasticity. Vane shear test have been done to determine the shear strength of soil. Software Slope/W has been used to analyse four cut slopes in the study area and found two cut slopes are stable and two cut slopes are unstable.