垂直裂隙对倾斜坡顶黄土边坡稳定性的影响  

Effects of Vertical Cracks on Loess Slope Stability with Inclined Crest

作　　者：赵海容 葛玉婷 杜岳涛 周志军[4] ZHAO Hai-rong;GE Yu-ting;DU Yue-tao;ZHOU Zhi-jun(Gansu Provincial Highway Development Cenrer,Lanzhou 730030,China;Shaanxi Provincial Transport Planning Design and Research Institute Co.Ltd.,Xi'an 710065,China;Shaanxi Province Railway Investment(Group)Co.Ltd.,Xi'an 710199,China;School of Highway,Chang'an University,Xi'an 710064,China)

机构地区：[1]甘肃省公路事业发展中心,兰州市730070 [2]陕西省交通规划设计研究院有限公司,西安市710065 [3]陕西省铁路投资(集团)有限公司,西安市710199 [4]长安大学公路学院,西安市710064

出　　处：《公路》2022年第10期48-54,共7页Highway

摘　　要：为研究垂直裂隙对黄土边坡稳定性的影响,基于极限分析上限定理,对具有垂直裂隙及倾斜坡顶的黄土边坡进行分析,推导出边坡的外功率及内能量损耗的计算公式,并结合强度折减法编写优化程序,寻找带裂隙边坡处于临界破坏状态时的安全系数及此时与之对应的垂直裂隙的位置。然后以黄延高速沿线某一黄土边坡为例进行验证,分别采用该方法及有限差分软件对边坡的安全系数进行计算,并研究了安全系数随着坡肩和坡顶裂隙间距离变化的规律。计算结果表明,理论计算与数值模拟得到的安全系数变化规律基本相同。安全系数随坡肩和裂隙间距离的增大而减小,当坡顶裂隙和坡肩之间距离到达某一临界值时,安全系数达到最小;之后随着距离的增加,安全系数有小幅度增长而后趋于稳定。且通过对比发现,有限差分法所得安全系数略大于理论计算方法结果,最终得到的安全系数相对误差为0.6%,可见该计算方法的准确性较好。In order to study the influence of vertical cracks on the stability of loess slope,a loess slope with inclined slope top and vertical cracks is analyzed.Formulas for the external work rates and internal energy dissipation rates of the failure mechanism are derived within the framework of limit analysis.An optimization program is developed in combination with the strength reduction method to search for the most critical failure mechanism and the corresponding upper-bound factor of safety as well as the corresponding position of vertical crack.In addition,taking one slope along Huangling-Yan’an Expressway as example,the safety factor of the slope is calculated by the proposed method and the finite difference method respectively,and the influence of the distance between the crack on the slope top and the slope shoulder on the stability of the loess slope is discussed.The results show that the distribution of safety factor obtained by those two methods are the same.Safety factor decreases with the increase of the distance and it reaches the minimum when the threshold of the distance is reached.Thereafter factor of safety increases slowly and finally remains stable.The results of the proposed method are slightly larger than that of the finite difference method,and the relative error of the final result is 0.6%,which shows the accuracy and rationality of this method.

关 键 词：公路路基 安全系数 理论分析 黄土边坡 垂直裂隙 

分 类 号：U416.1[交通运输工程—道路与铁道工程] P642.131[天文地球—工程地质学]