非饱和边坡锚托板支护结构稳定性分析  

Stability analysis of unsaturated slopes with anchor plate support structure

作　　者：彭俊国 黄宇豪 宋然然 章承志 PENG Junguo;HUANG Yuhao;SONG Ranran;ZHANG Chengzhi(School of Civil Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050

出　　处：《岩石力学与工程学报》2024年第6期1443-1454,共12页Chinese Journal of Rock Mechanics and Engineering

摘　　要：为了完善锚托板支护边坡的设计方法,根据边坡内部平衡提出锚托板尺寸的计算公式,通过变分法和极限平衡法得到非饱和锚托板支护边坡安全系数的计算公式。利用瞬态渗流模拟降雨工况,得到边坡安全系数随降雨时间的变化规律,并分析边坡安全系数变化的内部机制。通过4个算例将安全系数的计算结果与现有方法的计算结论进行对比,验证本文方法的合理性。分析降雨强度、地震工况和锚托板支护工况对边坡稳定性和滑移面的影响,结果表明强降雨和地震都会显著降低边坡稳定性,水平和竖直向上的地震力会导致更深的滑动面,而竖直向下的地震力却会导致更浅的滑动面。提出方法不仅可以计算饱和与非饱和边坡安全系数,而且可以计算瞬态渗流、稳态渗流下的边坡安全系数,有较强的适用性。为了便于工程应用,通过对比将锚托板布置在不同竖向间距时的边坡安全系数,给出锚托板竖向3 m间距布置的工程建议。提出锚托板尺寸设计的简便方法,由简便设计方法得到的锚托板尺寸远低于目前的经验设计尺寸。To improve the design approach of anchor plate supporting slope,the calculation formula of anchor plate size is proposed according to the internal balance of slopes,and the formula of the safety factor of unsaturated anchor plate supporting slope is obtained through the variational method combining limit balance method.By using transient seepage to simulate rainfall conditions,the variation rule of the slope safety factor with the rainfall time is obtained,and the internal mechanism of the slope safety factor variation is analyzed.The results of safety factor are compared with the results of the existing methods by 4 examples,and the rationality of the suggested formula is verified.The effects of the rainfall intensity,seismic conditions and anchor plate supporting conditions on slope stability and sliding surface are analyzed.The results show that heavy rainfall and earthquakes will significantly reduce slope stability.Horizontal and vertical seismic forces will lead to deeper sliding surface,while vertical downward seismic forces will lead to shallower sliding surface.The proposed approach can not only calculate the safety factor of saturated and unsaturated slope,but also calculate the safety factor of slope under transient seepage and steady seepage,and has strong applicability.In order to facilitate the engineering application,by comparing the slope safety factor when the anchor plates are arranged at different vertical spacing,the vertical 3m spacing arrangement of the anchor plate is given as engineering suggestion.A simple method for the size design of anchor plate is presented.The size of anchor plate obtained by the simple design approach is much lower than the existing empirical design size.

关 键 词：边坡工程 变分法 锚托板 瞬态渗流 地震作用 

分 类 号：P642[天文地球—工程地质学]