FLAC3D NUMERICAL SIMULATION OF RECURRENCE MECHANISM OF LANDSLIDE UNDER EARTHQUAKE LOADING

Earthquake is one of the main factors to affect the stability of slopes or landslides．The huge landslide on Bailongjiang was formed in toppling deformation of the bedding slope. It was in a stable state under natural conditions. After the 5.12 Wenchuan Earthquake,the huge landslide appeared moving phenomena including continuous linking crack and dislocation steps in the trailing edge of landslide. Especially,the rupture deformation of the landslide downstream area tended to be evident.This paper examines the recurrence mechanism of the huge landslide under the earthquake. It is based on the regional geological conditions of landslide. It investigates the basic features in detail and the recurrence phenomenon and the characteristics of landslide. It is accomplished a dynamic analysis of landslide recurrence with the software builtin module FLAC3D. The numerical simulation and analysis show thatthe deformation and damage of the landslide is affected deeply by terrain under earthquake loading. The landslide has an obvious amplification effect under the action of the seismic waves. Compared with the steady rock slope adjacent to the landslide,the landslide was more sensitive to the earthquake loading under the same earthquake magnitude. This result explains well the causes of recurrence of landslide under the 5.12 Wenchuan Earthquake．