考虑降雨影响的非饱和土基坑边坡突变失稳分析

ANALYSIS OF STABILITY OF SLOPE IN UNSATURATED SOIL AFFECTED BY RAINFALL INFILTRATION BASED ON CATASTROPHE THEORY

降雨入渗往往是非饱和土基坑边坡失稳的主要诱发因素之一,同时边坡失稳又具有突发性。基于突变理论提出了考虑降雨入渗影响的非饱和土基坑边坡稳定性分析方法。根据分析边坡稳定性的塑性极限方法的上限理论建立了边坡失稳尖点突变模型,并得出边坡突发式滑坡的特征关系式,用突变理论对非饱和土边坡稳定进行了初步研究。研究表明,基坑边坡失稳是一种突发性的破坏,外界环境的变化(如降雨入渗导致土体抗剪强度的降低)是基坑边坡发生突发性破坏的决定性因素。

A new method is proposed for analysis of the stability of slope in unsaturated soil affected by rain infiltration based on catastrophe theory,it is taken into account that rainfall infiltration is one of the major factor causing the slope failure of unsaturated soil and the failure is usually abrupt.The cusp catastrophe model is established by means of the upper bound theorem of plastic limit theory for analyzing the stability of slope.The characteristic formula of the failure of slope is also deduced.It also can be concluded that the environmental variations,for example rainfall infiltration that decreases the shear strength of unsaturated soil,are the determinative to the failure of slope.