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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。
Model test is an important technical means to study the mechanism of slope instability. It is also a commonly used test method to obtain the deformation and failure process of landslide through the inclined model. As a test loading method, the controllability of the inclined loading mode and the similarity of the stress field in the process of tilting are all the key issues that affect the application of this method. In order to study the controllability of the test method, taking the massive sliding body as an example, the influence process of the two test methods on the sliding safety factor of the sliding block is analyzed and calculated. The results show that the inclination loading method can be used along with the inclination The increase of the angle decreases the sliding safety factor of the slider continuously, while the centrifugal loading method only has a significant influence on the sliding safety factor of the slider only in the range of 1g ~ 10g. In order to compare the similarity of internal stress field before and after model tilt, a numerical model of physical model was established to simulate the stress field in slope under different tilt angles. The calculation results show that the stress state in the middle part of the slope remains stable during the tilting of the model. When the inclination angle is large, the stress state at the leading edge of the slope changes greatly, the possibility of plastic deformation of the leading edge increases, and the local stress Field changes are helpful to simulate the failure mechanism of reservoir landslides. In order to verify the application effect of inclined model to simulate the process of landslide failure, taking Qianqiangping landslide as the prototype, the inclined loading method was used to carry out the failure model test, and the failure process of the landslide was obtained. Compared with the results of the discontinuous deformation analysis (DDA) simulation, the damage morphology obtained by the model test is closer to the actual landslide.