基于不同失稳判据的黄土边坡稳定性数值计算分析  

Numerical Analysis of Stability of Loess Slopes Based on Different Instability Criterion

作　　者：王昕宇 钟佩文 张慧莉[3] 陈卓 田堪良[1,2,4] WANG Xinyu;ZHONG Peiwen;ZHANG Huili;CHEN Zhuo;TIAN Kanliang(Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China)

机构地区：[1]中国科学院水利部水土保持研究所,陕西杨凌712100 [2]中国科学院大学,北京100049 [3]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [4]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《人民黄河》2024年第3期143-147,155,共6页Yellow River

基　　金：国家重点研发计划项目(2017YFC0504703,2016YFE0203400);陕西省科技统筹创新工程计划项目(2013KTDZ03-03-01)。

摘　　要：安全系数是边坡稳定性评价的一项重要指标,依据不同失稳判据计算得到的安全系数存在差异,会直接影响边坡稳定性状态的评价。以万花山治沟造地工程台阶型开挖边坡为对象,运用FLAC3D有限差分软件,采用强度折减法,选择计算不收敛判据、塑性区贯通判据、位移突变判据3种失稳判据,对黄土边坡安全系数进行数值计算。对比分析3种判据所得的分析结果及优缺点表明:3种失稳判据得出的安全系数大小排序为位移突变判据>计算不收敛判据>塑性区贯通判据。计算不收敛判据使用简便,求解快速,但不能展示折减过程坡体塑性区的变化情况;塑性区贯通判据不宜单独作为边坡失稳判据,需要结合不平衡力综合评估,但可以展示坡体剪切和拉伸塑性区;位移突变判据求解过程复杂,但能真实地反映坡体位移变化导致的临界破坏状态。建议类似工程优先选用求解过程快速的计算不收敛判据,然后结合塑性区贯通情况与坡体位移变化状态对边坡稳定性进行综合评价。The coefficient of safety is an important index for the evaluation of slope stability.The safety coefficients calculated based on differ⁃ent instability criteria are significantly different,and the variability of the results will directly affect the evaluation of the stability state of slopes.In this paper,taking the step⁃type excavated slope of the Wanhuashan Trench Construction Project as the object,FLAC3D finite difference software was used to calculate the safety coefficient of loess slopes based on three different types of instability criteria,namely the calculation non⁃convergence criterion,the plastic penetration criterion and the displacement abruptness criterion,and to compare and analyze the differences,advantages and disadvantages of the evaluation results of the three criteria.The results of the study shows that there is a cer⁃tain difference in the magnitude of safety coefficients obtained by using different instability criteria,with the order of magnitude being dis⁃placement abrupt change criterion>computational non⁃convergence criterion>plastic penetration criterion.The computational non⁃conver⁃gence criterion is easy to use and fast to solve,but does not show the change in the plastic zone of the slope during the discounting process.The plastic penetration criterion is not suitable as a criterion for slope instability on its own,but needs to be combined with the unbalanced force rate to be assessed,but it can show the area of shear damage and stretching of the slope.The sudden change of displacement criterion is tedious to solve,but the solution process truly reflects the critical damage state due to the change of slope displacement.For practical condi⁃tions such as loess slopes,it is recommended to use the fast computational non⁃convergence criterion to evaluate the slope stability in combi⁃nation with the plastic zone penetration and the slope displacement change.

关 键 词：黄土边坡 失稳判据 安全系数 强度折减法 稳定性分析 

分 类 号：TV223.6[水利工程—水工结构工程] TU457[建筑科学—岩土工程]