Stability Of High-Filled Soggy Embankment Based On Strength Reduction Method

In construction of transport infrastructure of southwestern mountainous area, many high-filled and deep excavation sections were unavoidable built because of terrain restrictions. These sections usually locate at strong rainfall areas or near water body. Taking The Three Gorges as example, water line of reservoir region is as high as175meters, thus embankments near the reservoir are soaked in water. Under frequent change of water level and long-term effect of water soaking, embankments are more vulnerable to all kind of diseases, including differential settlement, slope failure, overall sinking and foundation softening. So the stability of high-filled soggy embankment has become a significant issue.Strength Reduction Method calculates safety factor by reducing intensity parameters of slope. Neither the shape nor the position of sliding surface needs to be determined in advance. Merit of this method is that the calculation is not restricted by the complexity of slope or by the ways of slicing. This thesis is to study stability of high-filled soggy embankment by Strength Reduction Method based on FLAC3D. Following studies will be carried out.a. Influences of material parameters, boundary conditions and meshing to slope safety factor are analyzed. Combining with strength reduction theory, suitable criterion for slope failure is chosen to formulate algorithm using FISH language of FLAC3D, in which arithmetic speed is the major concern. Results of this algorithm are compared with these of built-in algorithm to prove its correctness.b. Based on the calculation platform built above, influences of high-filled condition and soggy condition to embankment safety factor are analyzed though construction of finite difference model. Control factors of high-filled soggy embankment’s stability are determined and the effect of water level is quantized.c. Combining with a high-filled soggy embankment construction site in Chongqing Iron&Steel Company freight station field, stress and strain distribution of high-filled soggy embankment is studied based on both FLAC3D and Geo-Slope software. Then the safety factor is calculated to evaluate stability of high-filled soggy embankment.