Search

The occurrence of loess landslides is particularly closely related to rainfall. In order to deeply understand the promotional effect of rainfall infiltration on landslides, based on the investigation of “9?17” Baqiao landslide in Xi'an area of Shaanxi, the numerical simulation methods were used to systematically study the change response characteristics and spatial- temporal distribution laws of the relevant physical and mechanical parameters of the loess slope under the rainfall infiltration conditions, analyze the destabilization process of the slope from the perspective of the change of the safety factor of sliding surface, and reveal the initiation mechanism of this type of landslide. The results show that ① the action of rainfall causes a gradual decrease in the matrix suction of the slope soil, and the magnitude of the decrease varies at different distribution locations; ② before the initiation of the landslide, the range of high volume moisture of the slope body expands significantly with rainfall, and the volume moisture shows the law of decreasing from paleosoil layer to the adjacent loess layer; ③ the horizontal displacement of the slope is radially decreasing from the middle to the upper and lower parts of the slope body, while the vertical displacement gradually decreases from the top to the bottom, and the safety coefficient of its critical sliding surface gradually decreases with the process of rainfall infiltration; ④ the response time and magnitude of pore water pressure and the change of volume moisture in the soil at the nodal development site are earlier and stronger than those in other areas of the slope, and the regional distribution of the maximum shear strain within the slope is basically parallel to the slope surface, and the simulation results are consistent with the prototype landslide; ⑤ based on the unique water-sensitive nature of loess, and the influence of causal factors such as geological structure or human engineering activities, the existence of loess joints and fissures provides an advantageous channel for water infiltration and transport, and rainfall accelerates the process of loess subduction and slope structure destruction, changing the internal stress field, displacement field and hydrogeological conditions of the slope, which in turn promotes the occurrence of landslides. [ABSTRACT FROM AUTHOR]