NUMERICAL SIMULATION OF PROGRESSIVE FAILURE IN CUT SLOPE OF SOFT ROCK USING A SOIL-WATER COUPLED FINITE ELEMENT ANALYSIS

FENG ZHANG, ATSUSHI YASHIMA, HITOMI OZAKI, TOSHIHISA ADACHI and FUSAO OKA

ABSTRACT: In the present paper, based on an elastoplastic model with strain hardening and strain softening, a soil-water coupled finite element analysis is conducted to investigate the progressive failure of a cut slope in a model ground. In order to verify of the analyses related to the strain-softening behavior, numerical analyses are firstly conducted for plane-strain compression in different meshes and loading steps under complete drained condition. It is confirmed by the analyses that the analysis conducted in this paper has a small dependency on the mesh size. Then, the mechanical behaviors of a cut slope, such as the change of excessive pore-water pressure, the redistribution of stress in ground due to strain softening, the propagation of shear band and the progressive failure are discussed in detail by the soil-water coupled finite element analysis. It is found that a soil-water coupled analysis based on an elastoplastic model can describe the time dependent behavior of soft rock in boundary-value problems. It is also found that a soil-water coupled analysis based on a strain-softening model can simulate the progressive failure of a cut slope.

Key words: effective stress, FEM, progressive failure, slope, strain softening, time dependency (IGC: G6)