Geographic Information System (GIS) based stability analysis of rock cut slopes

Road construction is accompanied with the occurrence of the cut slopes. Therefore, when the roads are constructed in mountainous terrain, the number of slopes is increased and the slopes are widely scattered in the regional area. In addition, the stability of rock cut slope is mainly dependent upon geological characteristics such as discontinuities in rock mass. In this study, the regional stability analysis technique based on Geographical Information System (GIS) was developed and applied to practical case, in which the road construction was planned and the planned cut slopes were widely scattered. GIS is the effective tool to deal with the widely scattered and the enormous number of data. Various factors affecting on the slope stability analysis, such as the structural domain, the orientation and dip angle of the cut slopes, and the friction angle of discontinuities, were considered as the input parameters for GIS. By overlaying input data layers and using the developed computer algorithm, the factor of safety (F.S.) values, as an index of slope stability were calculated for each failure mode, which considered for stereographic analysis and limit equilibrium analysis simultaneously. In this research, the factors of safety for each failure mode are evaluated and the minimum factor of safety is also evaluated in the divided small area. In order to verify the developed analysis method, the results of the cut rock slope stability were compared with actual failure modes and locations in the study area. Finally, the stable and economically appropriate cut angle for the planned rock slopes were suggested by using the developed algorithm and applying allowable F.S. value.