Mechanical characters of relaxing zone of slopes due to excavation

摘要

The analysis for relaxing zone is very important for stability analysis of slopes,and it is difficultto confirm the boundary of relaxing zone because of excavation. Based on a typical case study by finite elementanalysis for excavation,the mechanical character and the distribution regulation for relaxing zone of slopes,especially the variety of differential principal stress and plastic zone,are researched in this paper. The resultsshows that: the change of differential principal stress tensor which is obtained by subtracting the stress tensorsbefore and after excavated can be used to confirm the range of relaxing zone; and the distribution and developmentof the negative differential principal stress zone is almost the same as the plastic zone; in the end,the stressattenuation plastic relaxing zone near excavation surface,the original stress zone far from excavation surfaceand the stress concentration elastic compressing zone between above two are partitioned.