Study On Dynamic Behavior Of Deformation And Failure Of Structural And Cohesive Soil Slope

Stability of soil slopes is an important research subject in geotechnical engineering. Failure of slopes is closely related to the deformation process. Therefore, to evaluate the stability of soil slopes, it has great significance in research on failure process and mechanism of soil slopes. Structural soils are characteristic by their cementation and macropore. Structural soil slopes have different deformation and failure properties from remoulded soil slopes and need further study.This thesis studies mainly on the static and dynamic deformation and failure law of structural and remoulded soil slopes through centrifuge modeling tests of man-made structural soil slopes. Dynamic response method was validated by dynamic centrifuge modeling tests on reomulded soil slopes. 3-Dimensioal numerical simulation of the main hill in Olympic Forest Park was conducted using this method. Main achievements are as follows:1. Centrifuge modeling tests on structural and remoulded soil slopes were conducted to reproduce the deformation and failure process of the two kinds of soil slopes under static loading. Main influence factors were discussed. The results show: (1) Deformation of remoulded soil slopes has a stage of uniform deformation, which is not clear in structural soil slopes. (2) Deformation right before the failure of remoulded soil slopes is significantly greater than that of structural soil slopes, whose failure acts much like brittle failure. (3) Locations of slide planes of structural soil slopes are much different from those of remoulded soil slopes.2. Centrifuge shaking table tests on structural and remoulded soil slopes were conducted to reproduce the deformation and failure process of the two kinds of slopes. Main influence factors were discussed. The results show: (1) Magnification factors of the slopes rise with the altitude. (2) Vertical residual deformation is greater in the higher part, while the horizontal residual deformation get greater from the medial axis outward. (3) Vertical residual deformation of structural soil slopes is clearly greater than that of remoulded soil slopes. (4) Deformation of slopes can be divided into three stages: small deformation, strain localization and post-failure. (5) Soil slopes with higher water content have greater residual deforamtoin and are easier to fail. (6) Slope gradient has a significant influence on the failure pattern.3. Numerical simulations of the centrifuge shaking table tests were conducted using the dynamic response method based on equivalent viscoelasticity model with residual deformation treatment. The results show: (1) The method is suitable for dynamic response of regular clay slopes. (2) The method has limitation on simulating the horizontal residual deformation of structural soil slopes.4. 3-Dimensional dynamic response of the main hill in the Olympic Forest Park was conducted. The results show that the acceleration increases with the altitude and decreases when water content gets higher. Seismic intensity has a small effect on the magnification factors. Residual deformation of the main hill increases with increasing water content and seismic intensity.