Regional Hillslope Stability Analysis under Rainfall Based on Characterization of Overburden Soil Layer Thickness

Zou Hao; Jia Lin; Zheng Lulu; Li Benxing; Cai Jingsen

doi:10.3799/dqkx.2023.025

Abstract：The overburden layer in the region conceives the shallow surface damage of slopes and is the main source for the regional slope damage. But,the spatial variation in the thickness of the overburden layer makes it difficult to reasonably determine the bottom of hazard development,which in turn makes it difficult for the stability assessment results to indicate actual landslide conditions. Taking Jiuzihe Town of Huanggang City as an example,the overburden thickness in this area was investigated in detail,and the spatial distribution of overburden thickness was determined by a geomorphic process-based method. On this basis,the stability of slopes in the study area under rainfall conditions was analyzed using a quantitative model of slope stability,and the distribution and likelihood of regional accumulated layer landslide were estimated accordingly. The results show that the proposed method is effective and highly practical,and that the estimated regional overburden thickness based on GIST model is close to the actual situation,mainly concentrated in 0.5-3.0 m. The reasonable determination of overburden thickness makes the evaluation results of regional slope rainfall infiltration stability more precise and has practical landslide indication significance. The basically stable and stable slopes are mainly distributed in the areas with large overburden thickness but small slope,such as terrace platform or floodplain. While the less stable and unstable slopes are mainly distributed in the reservoir and the bank of various tributaries. Short period of heavy rainfall has great influence on slope stability. This study is helpful to the development of regional slope disaster assessment towards the fine direction.