Mechanical properties and permeability evolution of sandstone subjected to the coupling effects of chemical-seepage-stress  

化学-渗流-应力耦合作用下砂岩力学特性及渗透演化规律研究

作　　者：WANG Wei CHEN Chao-wei CAO Ya-jun JIA Yun LIU Shi-fan SHEN Wan-qing 王伟;陈超维;曹亚军;贾云;刘世藩;沈挽青

机构地区：[1]Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China [2]Research Institute of Geotechnical Engineering,Hohai University,Nanjing 210098,China [3]University of Lille,CNRS,Centrale Lille,UMR 9013 Laboratoire de mecanique multiphysique et multiechelle,F 59000 Lille,France [4]Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Shenyang 110819,China

出　　处：《Journal of Central South University》2025年第2期552-565,共14页中南大学学报(英文版)

基　　金：Projects(12072102,12102129)supported by the National Natural Science Foundation of China;Project(DM2022B01)supported by the Key Laboratory of Safe Mining of Deep Metal Mines,Ministry of Education,China;Project(JZ-008)supported by the Six Talent Peaks Project in Jiangsu Province,China。

摘　　要：In this study,a series of triaxial tests are conducted on sandstone specimens to investigate the evolution of their mechanics and permeability characteristics under the combined action of immersion corrosion and seepage of different chemical solutions.It is observed that with the increase of confining pressure,the peak stress,dilatancy stress,dilatancy stress ratio,peak strain,and elastic modulus of the sandstone increase while the Poisson ratio decreases and less secondary cracks are produced when the samples are broken.The pore pressure and confining pressure have opposite influences on the mechanical properties.With the increase of the applied axial stress,three stages are clearly identified in the permeability evolution curves:initial compaction stage,linear elasticity stage and plastic deformation stage.The permeability reaches the maximum value when the highest volumetric dilatancy is obtained.In addition,the hydrochemical action of salt solution with pH=7 and 4 has an obvious deteriorating effect on the mechanical properties and induces the increase of permeability.The obtained results will be useful in engineering to understand the mechanical and seepage properties of sandstone under the coupled chemical-seepage-stress multiple fields.地下化学-渗流-应力耦合场对岩石力学、变形、渗流特性有重要影响,可能会严重危害地下工程岩体的安全和稳定。为研究在不同化学溶液浸泡腐蚀及渗流作用下岩石力学和渗透特性的演化规律,采用岩石全自动三轴伺服仪,对一种红砂岩开展了三轴压缩试验。结果表明,随着孔压增大,砂岩峰值应力和扩容应力比减小,而峰值应变增大,且破坏时产生较多次生裂缝,而渗透系数减小。此外,pH=7盐溶液的水化学作用对砂岩力学特性有优化作用,而pH=4盐溶液和蒸馏水的水化学作用对砂岩力学特性有劣化作用,并降低了砂岩的渗透系数。本研究结果可在工程中对在化学-渗流-应力多场耦合作用下砂岩的力学、渗流特性变化进行分析。

关 键 词：red sandstone chemical corrosion multi-field coupling mechanical characteristics permeability evolution 

分 类 号：TU45[建筑科学—岩土工程]