Research on Landslide Failure of Rainfall-type Accumulation Body Based on Physical Model

Abstract

The occurrence of landslides in accumulation bodies is significantly influenced by rainfall, which has been prevalent in southwestern China in recent times. Consequently, investigating the alterations in the internal volumetric water content, pore water pressure, and the migration patterns of fine particles within these bodies under varying rainfall scenarios holds considerable importance. Utilizing a physical model test, researchers delve into the failure mechanisms of the accumulation body under three distinct rainfall conditions, employing a multi-functional integrated sensor embedded within the model to facilitate this analysis. The test results are as follows: Under the rainfall conditions of 30, 50 and 70mm/h, the failure modes of accumulation slope are simple cracking, pull failure after traction and collapse failure respectively. With the gradual increase of rainfall, the response rate of sensors buried in the same location also increases, but the increase of pore water pressure is equivalent to the lag of volume water content. Through quantitative analysis, it is proved that fine particle migration is the direct factor of landslide of loose deposits induced by rainfall. Finally, the mechanism of slope instability and failure induced by different degrees of rainfall is proved, and the relevant results can provide scientific theoretical basis for the early warning of similar slope in southwest China.