应变软化土质边坡渐进破坏的演化模型

Evolution Model of Progressive Failure of Strain-softening Soil Slopes

考虑到土体的流变效应 ,通过推广不平衡推力法 ,提出了具有应变软化性质的土质边坡渐进破坏的一个力学模型 .该模型采用Maxwell松驰模型描述局部破坏后滑裂面上土体的抗剪强度随时间的变化情况 ,用时间安全系数来描述边坡的稳定状态 ,并且不必假定渐进破坏从坡角开始 ,因而更接近实际情况 .通过数值模拟 ,清晰地揭示了边坡渐进破坏的历时演化过程 。

In view of the effects of rheological characteristics of soil, a mechanical model of progressive failure of strain-softening soil slopes is presented by generalizing the method of unbalanced-thrust.The maxwell relaxation is introduced to desevibe the shear strength with time of the soil near the slip surface after local failure,and the safety factor varying with time is done to express the stability of the slope.Moreover,the assumption that the progressive failure starts at the corner first isn't necessary.Thus the presented model should be much close to the practice.The evolutional process of landslide can be clearly shown and the rule that the safety factor of slope is decrescent with time is validated by computer simulation using the model.