干湿循环导致粉砂质泥岩力学特性变化规律研究  

Study on the Variation of Mechanical Properties of Silty Mudstone Caused by Drying-Wetting Cycle

作　　者：赖增伟 玉达变 刘先林 吕玺琳[3] 任中俊[4] 庞磊 LAI Zengwei;YU Dabian;LIU Xianlin;LV Xilin;REN Zhongjun;PANG Lei(Guangxi New Development Transportation Group Co.,Ltd,Nanning 530029,Guangxi,China;Guangxi Communications Design Group Co.,Ltd.,Nanning 530029,Guangxi,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,Hunan,China)

机构地区：[1]广西新发展交通集团有限公司,广西南宁530029 [2]广西交通设计集团有限公司,广西南宁530029 [3]同济大学岩土及地下工程教育部重点实验室,上海200092 [4]湖南科技大学土木工程学院,湖南湘潭411201

出　　处：《力学季刊》2023年第2期407-417,共11页Chinese Quarterly of Mechanics

基　　金：广西重点研发计划(AB22080024);四川省科技计划(2021YFSY0037)。

摘　　要：受亲水矿物成分影响,水侵作用下粉砂质泥岩力学特性易劣化.开展多种干湿条件下粉砂质泥岩的单/三轴压缩试验,研究试样在饱水作用下的强度和刚度弱化,分析干湿循环对试样力学特性的影响规律.试验结果表明,粉砂质泥岩强度和刚度均随饱和度增加而明显降低,在中期变形阶段刚度下降程度明显大于早期变形阶段.粉砂质泥岩强度随围压增大而线性提高,其强度特性可采用Drucker-Prager准则描述,且试样开裂角符合剪切滑移破坏特征.干湿循环试验结果表明,粉砂质泥岩单轴抗压强度和割线模量随循环次数增大而近似线性衰减,并且其刚度衰减快于强度衰减.Affected by the hydrophilic characteristic of mineral composition,the mechanical property of silty mudstone is easy to deteriorate when subjected to water invasion.Uniaxial and triaxial compression tests of dried and saturated silty mudstone were carried out to study the influence of sample water content on its strength and deformation,and the evolution of mechanical property of silty mudstone caused by drying-wetting cycle was investigated.Test results show that both the strength and stiffness of silty mudstone decrease significantly with the increase of saturation.It is noticed that the stiffness degraded faster in the middle stage than that in early stage of the whole deformation process.The strength of specimen increases linearly with confining pressure,and their relation can be well described by Drucker-Prager criterion.The angle of failure plane for the specimen accords with the characteristics of shear slip failure.The uniaxial test results show that the uniaxial compressive strength and secant modulus of silty mudstone decrease approximately linearly with drying-wetting cycle,followed by that the secant modulus degraded faster than strength.

关 键 词：粉砂质泥岩 干湿循环 单轴试验 三轴试验 劣化 强度 

分 类 号：TU458.3[建筑科学—岩土工程]