Mechanism Of Landslides Induced By Rainfall Based On Air Infiltration Theory

In this paper,the mechanism of rainfall induced landslide is studied based on the gas cavity theory,and the content of capillary force in the mechanics of unsaturated soil is reflected from the occurrence of the infiltration peak phenomenon during the rainfall process.The Young-Laplace formula shows that there is a quantitative and qualitative relationship between the capillary force and the surface tension.Therefore,the surface tension and the capillary force in the traditional theory are summarized and analyzed.On the basis of the air penetration theory,the surface tension is analyzed and the micro mechanism of capillary force is studied.Some problems in the traditional theory are explained reasonably.On the basis of theoretical analysis,the concept of gas cavity inside the slope in the process of rainfall,the influence of the change of the gas cavity on the slope sliding after the rainfall and the rainfall are stopped,is put forward.Through the penetration test,the existence of the infiltration peak is verified,and the relationship between the formation of the infiltration peak and the particle size of the soil is concluded,and the particle size of the soil is the key factor affecting the capillary force of unsaturated soil,so the formation of the wetting peak and the capillary force of unsaturated soil are analyzed.The GEO-SLOPE software is used to simulate the slope of the gas cavity,and simulate the influence of the change of the position of the wetting peak on the slope sliding.Finally,the simulation results are in agreement with the theoretical analysis of the gas cavity.This paper is based on the theory of gas cavity to study the mechanism of rainfall induced landslides,and studies the surface tension and capillary force,and has a new understanding,and has obtained some valuable research results,including:(1)the research on the mechanism of rainfall induced landslides at home and abroad is summarized,the traditional theory of surface tension and capillary action is sorted out,and some of them are questioned.(2)A new explanation for the mechanism of surface tension and capillary force based on air infiltration is proposed.A series of problems such as the non existence of surface tension in the vacuum,the extreme value of capillary force and the applicability of the Young-Laplace equation are explained,and some problems which can not be explained in the traditional theory are explained.(3)the infiltration peak is simulated through the penetration test,and the existence of the soak peak is verified.The test shows that the particle size is the key factor affecting the formation of the infiltration peak.(4)Based on the new explanation of the mechanism of surface tension and capillary force based on the theory of air infiltration,the concept of gas cavity is put forward.The GEO-SLOPE software is used to simulate the position of the sliding surface of the slope with the gas cavity.The influence of the change of the position of the peak of the wetting peak on the slope of the slope is analyzed,and the simulation results are in agreement with the mechanism analysis.