平推式滑坡运动距离计算模型

平推式滑坡是四川盆地红层地区和三峡库区普遍存在的一类十分特殊的滑坡。多发育于近水平砂、泥岩互层的斜坡中，岩层倾角一般仅3°～5°，最陡者也不超过10°。基于平推式滑坡的地质力学模型及运动过程分析，利用能量守恒的原理推导了平推式滑坡运动距离的理论计算公式。进行了3组物理模型模拟试验，第Ⅰ组试验模拟滑坡后部裂缝在不同宽度及水头高度作用下滑坡体的运动距离，对推导的理论公式进行校验。通过对比分析认为，平推式滑坡前缘剪出口地下水排泄状态呈少量点状排泄时，滑坡基底扬压力分布形态整体上与矩形更加接近。为了进一步校验理论公式，进行了第Ⅱ组、第Ⅲ组试验，每组分别固定初始水头高度和初始裂缝宽度，模型设置了前缘整体渗水和完全堵塞两种情况。物理模拟试验验证了理论公式的可靠性和适用性。将理论公式应用于狮子山滑坡运动距离的计算，应用结果表明计算公式适用性良好。研究成果对平推式滑坡防治具有一定的指导意义。

Method of sliding distance calculation for translational landslides

Translational landslides are widely spread in red layers area in Sichuan Basin. This type of landslide develops in sub-horizontal bedrock composed of sandstone and mudstone, normally with the dip angle of 3 to 5 degrees, 10 degrees at most. Based on geo-mechanical model and sliding process analysis, with the application of the principle of energy conservation, we derived the theoretical sliding distance calculation formula of translational landslide. Three groups of physical simulation tests were established. Group test Ⅰ simulated the sliding distance under the water pressure generated under different conditions of widths and different water heads. Then the theoretical formula was tested by comparing the calculated results and group Ⅰ physical simulation test results. By comparison, the overall distribution shape of uplift pressure under the bottom of sliding body was close to rectangle with very few groundwater penetration points along the shear outlet. To verify the theoretical formula, group tests Ⅱ and Ⅲ were established thereafter. Each group of tests fixed the width and water head respectively. Meanwhile the shear outlet of physical model was set to two types totally blocked and totally seeping water. The results of three groups of physical simulation tests verified the reliability and applicability of theoretical formula. Applying the theoretical formula to Shizishan landslide to calculate the sliding distance, and the calculation results showed the good applicability of the method. The research has some guidance and practical value to prevention and mitigation of translational landslides.