降雨裂缝渗透影响下山体边坡失稳灾变分析

运用现代非线性分析中的突变论方法，研究了在降雨裂缝渗透影响下山体边坡可能发生突发性失稳滑坡和渐进演化性失稳滑坡的机理.针对在降雨裂缝渗透影响下由于软弱夹层介质的有效刚度侵蚀损伤导致的弱化效应，给出了山体边坡失稳滑坡的尖点突变理论模型.分析表明，降雨量、裂缝等外部环境因素的变化，以及滑坡面上软弱夹层介质的弹性区段与应变弱化区段的本构曲线拐点处的有效刚度比的变化会导致边坡失稳灾变；当由于边坡自身的上述非线性因素变化造成的影响达到一定程度时，在边坡稳定性演化过程中会出现明显的突变现象，这种突变的非线性现象出现的条件分别是边坡发生灾变性滑坡的突发因素和积累演化因素的表像.研究结果有助于认识边坡突发性滑坡灾变机理和灾变累积性演化机理，并进一步预测和防治山体滑坡.

Catastrophe analysis for disaster of mountain slope stability affected by rainfall seepage and surface crack

The catastrophe theory in the modern nonlinearly analysis was introduced to study the mechanism of mountain slope slip under paroxysmal instability and gradually evolutional failure.The effects of erosion damage due to rainfall seepage within the surface crack and the infirm soft layer were taken into account to express the soften evolution behavior of material strength and structural stiffness in the infirm slip layer of the mountain slope and develop the catastrophe hazard model.Analysis on occurring conditions of mountain slip disaster shows that the variation of external environmental conditions,such as rainfall,cracks and seepage,as well as the evolution of the internal effective stiffness ratio between the elastic region and the strain soften region at the turn around point on the constitutive curve of the material within the infirm layer on the slip surface may cause the topological relation of the catastrophe theory for the mountain slope stability problem.The catastrophe evolution of nonlinear slope stability appears the hazard behavior when the variation path of internal and external factors of the mountain slope stability system crosses into the "disaster trigon" of the bifurcation gather.This developed model may carry out some useful knowledge to understand the disaster mechanism and the evolutional or accumulative process of hazard factors in mountain slope stability problem,which may have an important meaning further to advance the technique of forecasting,preventing and controlling the disaster of mountain slope slip.