Study Of Mechanism Of Rainfall-Induced Loose Deposits Landslides Under Prolonged Drought

The mechanism of rainfall-induced landslides and corresponding evaluation method has always been a problem difficult to solve who academics and engineering are very concerned about. In recent years, the phenomenon of droughts-heavy rainfall alternating frequent on our global. According to the wide range of prolonged drought-heavy rainfall has appeared in China, the engineering properties deterioration of loose deposits, including changes of shear strength and flow properties. Based on the on-site monitoring, model tests and numerical analysis method, research on the failure mechanism of loose deposits in this environment. Firstly, use model test analysis the change of slope displacement,soil pressure and pore water pressure of slopes under prolonged drought slope and non arid slope. Then by establish a numerical model, use Geo Studio simulation the entire process of slope instability undermine, compare the processes of internal seepage and slope stability of different moisture content slope under the same rainfall. Finally compared the numerical simulation and experimental results. Reveal the mechanism of slope failure. The results of experimental and numerical show:1)In model experiment, with the ongoing rains, soil pressure and pore water pressure of slopes are changing.2) Under the same rainfall, prolonged drought slope is easier settlement and overall mobile than non arid slope. The loose deposits which experienced prolonged drought affected by rainfall is more significant, rainfall infiltration is easier. 3) Obtained by numerical simulation, during rainfall, the safety factor and stability of slopes decreases. After rainfall, the safety factor of slopes are gradually increasing, then tend to stabilized. The stability factor of prolonged drought slope always lower than non arid slope. The study results provides a basis how to design and governance such a slope under prolonged drought-heavy rainfall, It make a direct engineering guidance for design and disaster prevention of loose deposits in construction scope.