边坡物理模型倾斜加载方式的研究

模型试验是研究边坡失稳机制的重要技术手段，通过倾斜模型获得滑坡的变形破坏过程也是常用的试验方法。作为一种试验加载方法，倾斜加载方式的可控性、倾斜过程中应力场的相似性都是影响该方法应用的关键性问题。为了研究试验方法的可控性，以块状滑体为例，分析计算了模型倾斜和离心加载两种试验方法对滑块抗滑安全系数的影响过程，结果表明，倾斜加载方法可以随着倾斜角度的增加连续地降低滑块的抗滑安全系数，而离心加载方式仅在1g～10g范围内对滑块的抗滑安全系数产生显著影响。为了比较模型倾斜前后模型内部应力场的相似性，建立了物理模型的数值计算模型，模拟不同倾斜角条件下坡体内的应力场。计算结果表明，模型倾斜过程中，坡体中部应力状态保持稳定，倾斜角较大时，坡体的前缘滑带位置应力状态变化较大，前缘进入塑性变形的可能性增大，局部应力场变化有利于模拟水库型滑坡的破坏机制。为了验证倾斜模型模拟滑坡破坏过程的应用效果，以千将坪滑坡为原型，采用倾斜加载方式进行破坏模型试验，获得了滑坡的破坏过程。与非连续变形分析方法(DDA)模拟的结果相比，模型试验得到的破坏形态更接近实际滑坡。

Study of inclined loading mode on slope in physical model test

Usually a physical model can be built to simulate the failure process of slope and study the instability mechanism of slope,while inclined model is a typical loading method to simulate the failure process.As a loading method,the controllability of loading mode and similarity of stress field during inclining process are significant points that can influence the application of the method.In order to study the controllability of test,taking bulk slip mass for example,the influences of inclined model and centrifugal loading methods on anti-sliding safety factor of slip mass are analyzed.The results show that anti-sliding safety factor decreases persistently with the inclination angle increasing in the inclined loading mode.But the anti-sliding safety factors of centrifugal loading test are influenced obviously when the acceleration is in the range of 1g-10g(where g is acceleration of gravity).In order to compare the similarities of stress field in the model before and after inclining,a numerical model of physical slope is built to simulate stress fields with different inclination angles.The results show that the stress state in the middle of slope keep steady;the stress state in the front part of slope changes greatly when the inclination angle is larger;variation of local stress field is propitious to simulate the failure process of reservoir landslide.In order to verify the application effect of the inclined model to landslide failure process,a slope model test is taken based on the prototype of Qianjiangping landslide;the failure process of landslide is obtained.Comparing with the results simulated by discontinuous deformation analysis(DDA) method,the failure form obtained from inclined model test is closer to the real condition of landslide.