干湿循环条件下膨胀土强度的折减规律及边坡稳定性分析  

Analysis of Strength Reduction Law and Slope Stability of Expansive Soil Under Wetting⁃drying Cycle Conditions

作　　者：印昊 王艳芳 梁波 YIN Hao;WANG Yanfang;LIANG Bo(Jinling Institute of Technology,Nanjing 211169,China;China University of Mining and Technology,Xuzhou 221116,China;JSTI Group Co.,Ltd.,Nanjing 210019,China)

机构地区：[1]金陵科技学院,南京211169 [2]中国矿业大学,徐州221116 [3]苏交科集团股份有限公司,南京210019

出　　处：《现代交通技术》2024年第5期15-19,共5页Modern Transportation Technology

基　　金：国家重点研发计划项目(2019YFC1509800);国家自然科学基金青年科学基金项目(51908278);江苏省高校自然科学基金面上项目(19KJD410002)。

摘　　要：选取膨胀土边坡为研究对象,对干湿循环作用后的膨胀土开展直剪试验,分析其抗剪强度的变化规律。同时,借助有限元场变量,对膨胀土边坡进行稳定性分析,模拟干湿循环对土体强度的影响。研究结果表明:随着干湿循环次数的增加,膨胀土的主要抗剪强度指标(黏聚力和内摩擦角)数值逐渐减小,强度衰减主要发生在前3次干湿循环过程中,且黏聚力的减小幅度远大于内摩擦角;干湿循环会引起土体抗剪强度的减小,导致膨胀土边坡失稳滑塌。对膨胀土边坡稳定性进行分析时,需综合考虑干湿循环的不利影响,并针对其劣化效应采取合理的防治措施。The expansive soil slope is selected as the research object,and direct shear test is carried on the expansive soil after wetting⁃drying cycle to analyze the change law of its shear strength.At the same time,stability analysis is carried out on the expansive soil slope with the help of finite element field variables,and the effect of wetting⁃drying cycle on the strength of soil is simulated.The results show that the shear strength(cohesion and internal friction angle)of the expansive soil de⁃creases gradually with the increase in the number of wetting⁃drying cycles,and the decay mainly occurs in the first three wetting⁃drying cycles,moreover,the degree of decay of cohesion is much larger than that of internal friction angle;the wetting⁃drying cycles cause the shear strength of the soil to decrease continuously,which eventually leads to the instability of the expansive soil slope.In the stability analysis of expansive soil slope,it is necessary to consider the adverse effects of wetting⁃drying cycles,and take reasonable measures to prevent the deterioration of expansive soil.

关 键 词：膨胀土 干湿循环 强度折减 抗剪强度 稳定性分析 

分 类 号：U416.14[交通运输工程—道路与铁道工程] U416.167