岩屋庙膨胀土路堑边坡失稳特征及治理措施研究  

Failure characteristics of expansive soil cutting slope in Yanwumiao and its treatment measure

作　　者：何红忠 陈子昂 HE Hongzhong;CHEN Ziang(China Railway Wuhan Survey and Design Institute Co.,Ltd.,Wuhan 430074,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中铁武汉勘察设计院有限公司,湖北武汉430074 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《浙江工业大学学报》2023年第5期530-536,共7页Journal of Zhejiang University of Technology

基　　金：国家重点研发计划项目(2019YFC1509800)。

摘　　要：某铁路专用线岩屋庙膨胀土路堑边坡发生了多次滑塌破坏,采用土工格栅加筋方式对该边坡进行治理。为评估采用土工格栅加筋处置该路堑边坡的合理性,首先,通过现场调研分析该膨胀土路堑边坡失稳破坏特征;然后,结合岩屋庙膨胀土的膨胀性,利用升温膨胀方式模拟膨胀土的遇水膨胀特性;最后,建立可考虑膨胀土膨胀性特点的膨胀土路堑边坡有限元数值模型,以研究土工格栅加筋处置该膨胀土路堑边坡的有效性。研究结果表明:考虑坡顶堆载与土体膨胀共同作用时,该路堑边坡稳定性系数从1.444降至1.034。受坡顶堆载的影响,边坡呈现为推移式滑动破坏。通过土工格栅加筋处理可有效提高该路堑边坡的稳定性。从经济成本与治理效果角度考虑,选用土工格栅拉伸强度不小于50 kN/m,加筋间距为1.0 m的方案较为可靠,此时路堑边坡稳定性系数达到1.467,满足边坡安全需求。The expansive soil cutting slope of a railway line in Yanwumiao collapsed several times,and geogrid reinforcement was adopted to treat the expansive soil slope.To evaluate the rationality of the treatment measure of geogrid reinforcement for such an expansive soil cutting slope,the failure characteristics of the expansive soil cutting slope is first clarified based on field investigations.Combined with the expansive property of expansive soil in Yanwumiao,the expansion caused by temperature rise is then used to simulate the swelling property of expansive soil.Finally,a numerical model of the cutting slope considering the expansive soil characteristics is established to study the effectiveness of geogrid reinforcement to treat the expansive soil cutting slope.The results show that the safety factor of the cutting slope decreases from 1.444 to 1.034 when overloading and soil expansion are considered.Due to the effect of overloading at the top of the slope,a sliding failure mode of the slope is observed.In view of the economic cost and the treatment effect,it is reasonable to adopt the treatment measure by using a geogrid tensile strength of not smaller than 50 kN/m and a vertical reinforcement spacing of 1.0 m.After the treatment measure is taken,the safety factor of the slope increases to 1.467,which meets the safety requirement of the slope.

关 键 词：边坡 膨胀土 堆载 加筋土 

分 类 号：U146[交通运输工程]