物质点强度折减法边坡失稳判据选择方法  

Slope failure criterion for the strength reduction material point method

作　　者：蒋先平 张鹏[2,3] 卢艺伟 刘磊磊 张明辉[1] Jiang Xianping;Zhang Peng;Lu Yiwei;Liu Leilei;Zhang Minghui(China Nonferrous Metals Changsha Investigation and Design Research Institute Co.,Ltd.,Changsha 410011,China;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring of Ministry of Education,Central South University,Changsha 410083,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China)

机构地区：[1]中国有色金属长沙勘察设计研究院有限公司,长沙410011 [2]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,长沙410083 [3]中南大学地球科学与信息物理学院,长沙410083

出　　处：《地质科技通报》2022年第2期113-122,共10页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金青年基金项目(41902291);湖南省自然科学基金项目(2020JJ5704);中南大学中央高校基本科研业务费专项资金项目(2021zzts0810)。

摘　　要：用物质点强度折减法求解边坡安全系数时,需要选择一定的失稳判据,而采用不同的失稳判据获得的安全系数通常存在一定差异。为此,采用物质点强度折减法对两个边坡算例进行了稳定性分析,对比研究了文献中常用的4种边坡失稳判据(计算不收敛、特征点位移突变、塑性应变贯通及界限值判据)在计算边坡安全系数时的合理性及适用性。同时,将Spencer极限平衡法获得的安全系数作为参考,进一步验证了结果的合理性与准确性。结果表明:①数值计算的收敛性不能作为边坡失稳判据;②将特征点位移突变视为边坡失稳判据时,获得的安全系数与极限平衡法获得的结果基本一致,故特征点位移突变可以作为边坡失稳判据;③塑性应变贯通和边坡最大位移随迭代时间步趋于稳定的界限值不宜单独作为边坡失稳判据。It is necessary to select an instability criterion for the material point strength reduction method(SRMPM)to solve the slope safety factor(F_(s)),and there are some differences in the obtained F_(s) values with different instability criteria.To examine the rationality and applicability of the four common instability criteria(i.e.,calculation nonconvergence,displacement mutation of the feature point,transfixion of the plastic zone and the limit value),this paper uses the SRMPM to analyse the stability of two slope examples.The F_(s) obtained by the Spencer limit equilibrium method(LEM)is taken as a reference to further verify the rationality and accuracy of the results.The results show that①the material point calculation is convergent,so the calculation nonconvergence cannot be used as the slope instability criterion;②when the displacement mutation of the feature is regarded as the criterion of slope instability,the F_(s) is basically consistent with the LEM,so the displacement mutation of the feature point can be used as the slope instability criterion;and③the limit value and the transfixion of the plastic zone cannot be used alone as the slope instability criterion.

关 键 词：边坡稳定性分析 物质点法 强度折减法 失稳判据 安全系数 

分 类 号：P642.22[天文地球—工程地质学]