重载铁路路堑边坡极限状态法稳定性分析研究

A Study on Stability Analysis for Cutting Slope of Heavy Haul Railway by Limit State Method

选取山区重载铁路(朔黄铁路龙宫站区)的典型路堑边坡,分析了自重、自重+地震及自重+暴雨等工况下边坡的稳定性,采用一般分离法得出山区重载铁路不同工况下的作用分项分数和抗力分项系数,并将其与铁路路基规范中的建议分项系数进行了对比。结果表明:(1)朔黄龙宫站区铁路路堑边坡易形成滑坡的部位位于坡高的0.47倍处,属于欠稳定和不稳定边坡;(2)朔黄龙宫站区路堑边坡的抗力分项系数小于规范规定的取值;(3)自重+暴雨条件下,∑W_(i)sinθ_(i)该项增加剧烈,降低土体的抗剪强度,边坡失效概率下降10%,∑W_(i)sinθ_(i)的分项系数会降低0.1~0.2。研究成果对极限状态设计在山区重载铁路路堑边坡的应用有一定参考作用,并对山区重载铁路路堑边坡的安全性设计和方案治理具有实际指导意义。

A typical cutting slope of heavy haul railway in mountainous areas(Longgong Station Area of Shuozhou-Huanghua Railway)was taken as an example,to analyze the stability of slopes under dead weight,dead weight+earthquake and dead weight+rainstorm conditions,and general separation method was used to obtain the partial score of action and the partial coefficient for resistance of heavy haul railway in mountainous areas under different working conditions,which were then compared with the recommended partial coefficients in railway subgrade specifications.The results show that:(1)In Longgong Station Area of Shuozhou-Huanghua Railway,the part of the railway cutting slope which is prone to landslide is located at 0.47 times the slope height,belonging to the less stable and unstable slope.(2)The partial coefficient of cutting slope resistance in Longgong Station Area of Shuozhou-Huanghua Railway is less than the value specified in the specification.(3)Under the condition of dead-weight+rainstorm,ΣW_(i)sinθ_(i) increases sharply,which reduces the shear strength of soil mass,decreases the failure probability of slope by 10%,and the partial coefficient of ΣW_(i)sinθ_(i) will decrease by 0.1~0.2.The conclusions have certain reference significance for the application of limit state design in the heavy haul railway cutting slopes in mountainous areas and have practical guiding significance for the safety design and scheme governance of railway cutting slopes in mountainous areas.