根据应力场和位移场判断滑坡的破坏类型及最优加固位置确定

 滑坡的类型通常有推移式、牵引式和复合式。基于数值分析方法结合变模量弹塑性强度折减法，可以得到滑坡体的应力场和位移场。根据数值分析结果，发现推移式滑坡的上部位移和应力水平高于下部，而牵引式滑坡的下部位移和应力水平大于上部，复合式滑坡则是推移式和牵引式的组合，从而可以根据应力场和位移场较明确地确定滑坡体的滑坡类型。通过假设采用抗滑桩加固滑坡体，设定抗滑桩处于不同的位置，研究其安全系数大小与坡体应力场和位移场的关系，发现当抗滑桩置于应力水平和位移较大的部位时可以获得较大的安全系数，因而推移式滑坡的最优加固位置在坡体上部，牵引式滑坡的最优加固位置在坡体下部，复合型滑坡的最优位置在坡内应力水平和位移较大的部位。因此，可以根据数值分析得到的应力场和位移场确定滑坡的最优加固位置，为工程处理提供较明确的合理加固位置，对指导滑坡处理有较好的意义。最后通过对几个典型滑坡的计算分析，验证该方法的合理性和可行性。

IDENTIFICATION OF LANDSLIDE TYPE AND DETERMINATION OF OPTIMAL REINFORCEMENT SITE BASED ON STRESS FIELD AND DISPLACEMENT FIELD

Failure types of landslides generally include thrust load-caused type,retrogressive type and combined type.Stress field and displacement field were obtained based on numerical analysis and variable modulus elastoplastic strength reduction method.According to the numerical results,it is found that in thrust load-caused landslide,the displacement and the stress level of the upper region are higher than those of the lower region;while in retrogressive landslide,the displacement and the stress level of the lower region are higher than those of the upper region;and the combined landslide is the combination of those two failure types.Therefore,the failure type of a landslide can be clearly identified by its stress field and displacement field obtained from numerical method.Furthermore,anti-sliding piles were set at different sites of landslide to study the relationships between factor of safety and stress field and displacement field of landslide.It is found that setting the anti-sliding piles at the site of higher stress level and larger displacement can lead to higher factor of safety than at other places.Thus,the optimal reinforcement site is the upper region for the thrust load-caused landslide,while the lower region for the retrogressive landslide.As for the combined landslide,the optimal reinforcement site is the one of higher stress level and displacement.As a result,the optimal reinforcement site can be determined by the stress field and displacement field.These conclusions can offer more clear and reasonable reinforcement sites for engineering treatment,beneficial for the landslide treatment.At last,some typical landslides were analyzed.The results show that the above method is reasonable and feasible.