基于极限平衡理论的水平成层土质边坡稳定性分析

发布时间：2018-04-19 15:28

本文选题：水平成层土质边坡 + 破坏机理　；参考：《湖南科技大学》2015年硕士论文

【摘要】：传统土质边坡稳定性研究的成果丰硕,但水平层状土质边坡具有其特殊的破坏方式以及承载特性,因此对水平层状土质边坡的研究具有实用价值。在采用室内模型试验与数值模拟确定水平成层土质边坡的破坏机理及承载特性的基础上,通过极限平衡法对水平层状土质边坡的稳定性计算方法进行研究。得出:1、通过室内模型试验模拟水平层状土质边坡在坡顶荷载下边坡的竖向沉降、水平位移、极限承载力及破坏模式,得出:水平层状土质边坡破坏面形式为圆弧面+平面,竖向沉降最大值产生于坡顶加载板位置处,水平位移最大值出现在边坡薄弱层处;通过不同工况对比分析发现,水平层状边坡的极限荷载随着层厚增大而增大,边坡高度对极限荷载的影响不明显。2、运用数值模拟对室内五组模型试验进行分析,其分析结果与模型试验较为接近;通过数值模拟得出了:(1)水平层状土质边坡在坡顶不同加载宽度、不同层厚、不同坡比的滑动面剪出位置的变化情况;(2)水平成层土坡滑动面剪出高度与加载宽度之间的关系;(3)极限荷载随着层厚、坡比的增大而增大;当荷载作用范围增大时,极限承载力随之减小。3、运用极限平衡法基本理论,针对圆弧面+平面组合型滑动面的破坏模式,推导了水平层状土质边坡极限平衡竖向条分法极限承载力计算公式,该公式同时满足力平衡以及力矩平衡,且计算结果与室内模型试验结果较为接近。4、考虑到水平层状土质边坡分层特性,依托极限平衡理论,将水平条分法运用于该类边坡的稳定性计算中,推导了其稳定性系数以及极限承载力的计算公式。利用该公式计算得到的结果较之于室内模型试验结果偏高,其平均差值小于竖向条分法与模型试验结果的差值。5、以数值分析得到的滑动面为基础,简要的推导了水平层状边坡三维极限平衡稳定性系数的计算公式,且其计算结果与数值分析结果较为接近,三维极限平衡法具有一定的参考意义。
[Abstract]:The research on the stability of the traditional soil slope is fruitful, but the horizontal layered soil slope has its special failure mode and bearing characteristics, so it is of practical value to study the horizontal layered soil slope.On the basis of indoor model test and numerical simulation to determine the failure mechanism and bearing characteristics of horizontal layered soil slope, the stability calculation method of horizontal layered soil slope is studied by limit equilibrium method.Through indoor model test, the vertical settlement, horizontal displacement, ultimate bearing capacity and failure mode of horizontal layered soil slope under top load are simulated. It is concluded that the failure surface of horizontal layered soil slope is arc plane.The maximum vertical settlement occurs at the top of the slope, and the maximum horizontal displacement occurs in the weak layer of the slope. Through the comparative analysis of different working conditions, it is found that the ultimate load of the horizontal layered slope increases with the increase of the layer thickness.The influence of slope height on ultimate load is not obvious. 2. Numerical simulation is used to analyze five groups of indoor model tests, and the results are close to those of model tests.Through numerical simulation, it is obtained that the horizontal layered soil slope has different loading width and different layer thickness at the top of the slope.The relationship between the shear height and the loading width of the sliding surface of the horizontal soil slope increases with the increase of the thickness of the floor and the slope ratio, and increases with the increase of the load range.The ultimate bearing capacity of horizontal layered soil slope is reduced by using the basic theory of limit equilibrium method, and the formula of ultimate bearing capacity of horizontal layered soil slope by using the ultimate equilibrium vertical strip method is derived according to the failure mode of the combined sliding surface of arc plane.The formula satisfies both force balance and moment balance, and the calculated results are close to that of indoor model test. Considering the stratification characteristics of horizontal layered soil slope, the formula relies on the limit equilibrium theory.The horizontal strip method is applied to the stability calculation of this kind of slope, and the formula of its stability coefficient and ultimate bearing capacity is derived.The calculated results obtained by this formula are higher than those of indoor model tests, and the average difference is less than that of vertical strip method and model test results, which is based on the sliding surface obtained by numerical analysis.The calculation formula of 3D limit equilibrium stability coefficient of horizontal layered slope is deduced, and the result is close to that of numerical analysis. The 3D limit equilibrium method has certain reference significance.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43

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