摘要
为了分析南方湿热地区粉砂质泥岩边坡浅层失稳机制,开展不同干湿循环路径下的粉砂质泥岩低围压三轴压缩试验与扫描电镜(SEM)试验.基于连续损伤理论和修正Drucker-Prager(D-P)强度准则,构建可考虑干湿循环路径影响的粉砂质泥岩损伤本构模型.结果表明:粉砂质泥岩应力-应变曲线具有非线性特征,可分为压密阶段、弹性阶段、塑性屈服阶段、峰后破坏阶段和残余强度阶段;随干湿循环次数或循环幅度的增加,压密阶段与塑性屈服阶段延长,岩样峰值强度、变形模量、黏聚力和内摩擦角损伤逐渐增大,粉砂质泥岩力学参数敏感度表现为变形模量>黏聚力>内摩擦角>峰值强度;受溶蚀、潜蚀作用,粉砂质泥岩孔隙率不断增大,破坏模式由以剪切破坏形式为主的顶锥-劈裂破坏向剪切破坏演化.构建的岩石损伤本构模型能考虑干湿循环路径的影响,能较好地反映粉砂质泥岩应力-应变曲线全过程变形特征.
Low confining pressure triaxial compression tests and scanning electron microscopy(SEM)on silty mudstone were carried out under different drying-wetting cycle paths,respectively,in order to analyze the shallow instability mechanism of silty mudstone slopes in the hot and humid regions of southern China.A damage constitutive model for silty mudstone considering the influence of drying-wetting cycle paths was established based on the continuum damage mechanical theory and the modified Drucker-Prager(D-P)strength criterion.Results showed that the stress-strain curves of silty mudstone manifested non-linear characteristics,and could be divided into the compaction stage,elastic stage,plastic yield stage,post-peak failure stage,and residual strength stage.The compaction stage and the plastic yield stage were prolonged,and the peak strength,deformation modulus,cohesion and internal friction angle damage of silty mudstone gradually increased,with the increase in drying-wetting cycle times or drying-wetting cycle amplitudes.The sensitivity of the mechanical parameters of silty mudstone was as follows:deformation modulus>cohesion>internal friction angle>peak strength.The porosity of silty mudstone kept growing gradually due to erosion and dissolution.The failure mode of silty mudstone specimen evolved from conesplitting failure,mainly in the form of shear failure,to shear failure.The constructed rock damage constitutive model can consider the influence of drying-wetting cycle paths and reflect the deformation characteristics of the full stressstrain curve of the silty mudstone.
作者
成辉
付宏渊
曾铃
于晓伟
罗锦涛
刘杰
CHENG Hui;FU Hongyuan;ZENG Ling;YU Xiaowei;LUO Jintao;LIU Jie(School of Civil Engineering,Changsha University of Science and Technology,Changsha 410114,China;School of Hydraulic and Environmental Engineering,Changsha University of Science and Technology,Changsha 410114,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2024年第9期1912-1922,1980,共12页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(52108397,52078067,52078066)
湖南省自然科学基金资助项目(2022JJ40485)
长沙理工大学专业学位研究生“实践创新与创业能力提升计划”资助项目(CLSJCX22037)
湖南省水利科技资助项目(XSKJ2022068-26,XSKJ2023059-41).
关键词
粉砂质泥岩
干湿循环路径
力学特性
微观结构
损伤本构模型
silty mudstone
drying-wetting cycle path
mechanical property
microstructure
damage constitutive model
