桂南花岗岩残积土边坡稳定性分析及坡率优化建议  

Stability Analysis of Granite Residual Soil Slope in South Guangxi and Suggestions for Slope Ratio Optimization

作　　者：王豪 WANG Hao(China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 100162,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京100162

出　　处：《路基工程》2024年第2期107-110,共4页Subgrade Engineering

基　　金：中铁第五勘察设计院集团有限公司项目:滑坡与抗滑桩体系变形时效规律与长期稳定性研究(T5Y2022-C04)。

摘　　要：基于桂南地区岑溪—大新公路信宜至玉林(广西段)高速公路地质勘察资料,统计分析花岗岩残积土室内试验指标的规律及变异性,结合现场调查情况开展非饱和渗流应力耦合花岗岩残积土边坡稳定性数值模拟,研究降雨条件下不同边坡坡率与稳定系数的关系。结果表明:花岗岩残积土物理力学指标具有明显的变异性,黏聚力指标变异性最大;花岗岩残积土边坡坡率较缓时增加了降雨入渗及冲刷,但过陡又容易引起边坡失稳;边坡坡率为1∶0.75时可充分利用花岗岩残积土自身强度。建议边坡设计时设置合理坡率,可采用上缓下陡、分级开挖方案,单级边坡坡率取1∶0.75~1∶1.50(上部边坡坡率可适当放缓)。Based on the geological survey data of the Xinyi—Yulin(Guangxi section)expressway of the Cenxi—Daxin highway in the southern Guangxi region,the regularity and variability of the indoor test indicators of granite residual soil were statistically analyzed.Combined with field investigation,the stability of unsaturated seepage stress-coupled granite residual soil slope was simulated,the relationship between different slope ratios and stability coefficients under rainfall conditions was studied.The results show that the physical and mechanical indexes of granite residual soil have obvious variability,and the variability of cohesion index is the largest.When the slope ratio of granite residual soil is slow,rainfall infiltration and erosion increase,but it is too steep and easy to cause slope instability.When the slope ratio is 1∶0.75,the strength of granite residual soil can be fully utilized.It is recommended to set a reasonable slope ratio during the slope design,which the graded excavation scheme can be used to slow up and steep down,and the singe-stage side slope ratio should be 1∶0.75−1∶1.50(the upper side slope ratio can be slowed down appropriately).

关 键 词：花岗岩残积土 参数统计 流固耦合 边坡稳定性 坡率建议 

分 类 号：U416.14[交通运输工程—道路与铁道工程]