地下水作用下斜坡燕尾突模型研究

考虑滑面介质和上部岩体由不同力学性质的材料组成，上部岩体为弹性介质，滑带介质为应变软化介质。对应变软化介质，存在损伤软化与水致软化两种软化方式。用Weibull分布描述滑带介质的剪应力与应变关系，建立了斜坡系统的燕尾突变模型。通过分析，发现斜坡失稳与刚度比和滑带介质的含水率具有极大关联性。随着含水率的增加，斜坡开始滑动时的ξ0值不断降低，突跳时ξ*值也随着降低。此时的临界值x*增大，突跳量△x变小。同时含水率的不断增加，上部岩体和滑带介质的刚度比不断增大。刚度比的增大和含水率的增加引起的斜坡变形具有相似的规律。因此，正是由于含水率的增加和刚度比的增大，导致斜坡失稳的危险性增大，这也是降雨情况下斜坡容易失稳的根本原因所在。

Research on swallow-tailed catastrophe model for slope under effect of groundwater

The sliding face and the upside rock body are composed by different mechanical property materials. The upside rock body is elastic medium (called medium 1); the sliding belt medium is strain-softening medium (called medium 2). Damage softening and water softening exist to the medium 2. The shear stress-strain relationship is described by the Weibull’s distribution law. In this way, a swallow-tailed catastrophe model of landslide system is established. Through the analysis, it is discovered that the slope steadily have enormous relatedness with the stiffness ratio λ of medium 1 and medium 2 and the water content of sliding surface medium. Along with the increase of water content the value of ξ0 decreases when slope starts to slide, and the value of sudden jump ξ* decreases when skip occurs. At the same time, the critical value x* increases, the skip quantity △x decreases, and λ increases. It is found that the increase of λ or water content has the same distortion rule to slope. That’s why under the condition of rainfall, the landslide becomes unstable easily.