新疆伊宁县克孜勒赛滑坡成灾机理和动力学特征

Formation mechanism of the Kezilesai Landslide in Yining Country,Xinjiang and its dynamic characteristics

在对克孜勒赛滑坡野外地质调查的基础上,查明了该滑坡的诱发因素主要为冰雪融水和短时强降雨入渗。利用滑坡运动全过程演化方法,概化其孕灾模式:冻胀作用致使黄土节理裂隙扩大→山脊两面临空,后缘拉应力集中,加剧了节理裂隙受拉扩张程度→气温回升,融水入渗,滑体增重→短时强降雨触发滑坡失稳。在此基础上,通过滑坡动力学模型DNAW模拟,选取FVF模型对该滑坡的运动全过程进行模拟分析,得到滑坡的前后缘运动速度、滑体形态变化等运动特征要素。这些为西北地区类似的黄土滑坡的成灾机理及运动特征分析提供参考,进一步为防灾减灾工作提供理论支撑。

On the basis of the detailed geological survey on the Kezilesai Landslide,it is found that the main inducing factors of the landslide are the melt water and heavy rainfall infiltration. Using the method of the motion evolutionary process of a landslide,we generalized the formation model of the Kezilesai Landslide. The model is given as follows： firstly,the frost heaving resulted in enlargement of loess joint fissure. And because the both sides of ridge are free faces,stress concentration at the trailing edge caused intensely the enlargement of loess joint fissure. With the rise of temperature and melt water infiltration,the sliding body weight increased again. When the short-term heavy rainfall occurs,it made the slope instable. And the dynamic characteristics of the Kezilesai Landslide were analysed based on the kinetic model of DAN-W. Using the FVF model to simulate the whole process of landslide,the results offer the velocity of the trailing edge and leading edge and the shape variation of the landslide. These results are consistent with the actual situation. These provide reference for the analysis of the mechanism and movement characteristics of similar loessland-slides in northwest loess areas,and further provide the theoretical support for disaster prevention and reduction.