Establishing Reliable Slope Stability Hazard Map Based on GIS-Based Tool in Conjunction with Finite Element Methods

Abstract

This paper describes the establishment of a slope stability hazard map based on a GIS-based tool in conjunction with the finite element method (FEM). In this regard, Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) images were modeled using the Weight of Evidence (WOE) technique. The previous simulation was therefore validated using visual observations and FEM (Phase 2D and SLIDE). The above techniques made it possible to develop and validate the reliable slope stability hazard map with the use of a case study. The results show that the established hazard map correlates very well with visual observation and stability assessment performed using FEM models. The map categorises slopes based on their susceptibility to failure; however, it has been discovered that most of the slopes that rated highly susceptible were located along or closer to geological features (faults) or streams and were at high elevations. Similarly, the SLIDE model has been utilised to perform the safety factor of the identified slope and the model has shown that those slopes were not stable. Furthermore, the influence of geological features was further studied using the Phase 2D model and it was discovered that the features contributed largely to the displacement of the rock mass with time, and as a result, instability was expected. The overall conclusion of the study is that the combination of geotechnical and GIS-based tools appeared to provide an insight in categorising the hazard of slopes located within mountainous terrain.