Analysis of the Potential for Nearly Circular Slope Failure Using On-site Survey Information with Adverse Calculation

摘要

Slope stability analysis is crucial for decreasing unwanted economical loss at mountain highways which are prone to damage from heavy rains. The objective of this study is to perform on-site investigation and adverse calculation of slope damage at a specified road section along Tai-27 highway in Taiwan. By analysing a total of 38 on-site survey results, it is found that the types of slope damage may include debris flow (26%), shallow soil layer sliding (26%), nearly circular sliding (8%), slope oriented sliding (3%), falling rock (11%), river erosion (13%), and others (13%). Based on available geological information at three locations with nearly circular slope failure, the adverse calculations using computer software show that these slopes all failed at a shallow soil layer. Some of the important soil strength parameters such as cohesion force and friction angle are estimated, and a critical sliding surface is predicted for a minimum safety factor. The results provide useful information for choosing a suitable engineering protection work at these hazardous locations by the relevant agency.