Application of SSRM in stability analysis of subgrade embankments over sloped weak ground with FLAC3D

摘要

Subgrade embankments over sloped weak ground exhibit different deformation behavior due todownhill sliding potential compared to filling over flat ground. The stability analysis of subgrade embankmentsover sloped weak ground plays an important role in embankment design process. Some numerical simula-tion software packages including Shear Strength Reduction Method (SSRM) to analysis slope stability weresummarized. Based on Finite Difference Method (FDM) software package FLAC3D,3D stability analysis ofembankments over sloped weak ground was performed. The influences of some model geometry parameters,such as the weak subsoil layer longitudinal length and vertical thickness,on potential slip surface behavior andFactor of Safety (FS) were discussed. The research results present the considerable differences between the slipsurface behavior and Factors of Safety (FS) of an embankment over sloped weak ground estimated from 2D and3D numerical calculations. The slip surface behavior depend on the weak subsoil layer longitudinal length andvertical thickness seriously. It seems that FS obtained from 2D calculations may be underestimated when theweak subsoil layer longitudinal length is limited. FS obtained from 2D calculations were lower than from 3D.With the rapid development of computer hardware and available commercial numerical simulation software,application of Shear Strength Reduction Method (SSRM) in 3D seems to be a reasonable alternative to 2Danalysis to take the complexity of geology under consideration--especially the presence of thin and weak strata.