酸性干湿循环下泥质砂岩劣化及声发射演化特征识别研究  

Degradation of argillaceous sandstone and identification of acoustic emission evolution characteristics under acidic wet-dry cycles

作　　者：隆能增 任松[1,2] 吴斐[1,2] 陈征 陈国庆[1,2] 张平[1,2] 张闯[1,2] LONG Neng-zeng;REN Song;WU Fei;CHEN Zheng;CHEN Guo-qing;ZHANG Ping;ZHANG Chuang(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学资源与安全学院,重庆400044

出　　处：《岩土力学》2024年第9期2653-2668,共16页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52074048,No.51774057);重庆市自然科学基金面上项目(No.CSTB2022NSCQ-MSX0914);煤矿灾害动力学与控制国家重点实验室自主项目(No.2011DA105287-MS202122)。

摘　　要：为深入探究降雨−蒸发干湿循环效应及酸雨腐蚀对泥质砂岩边坡运营稳定性的影响,基于不同酸性干湿循环下泥质砂岩单轴压缩、三轴压缩及声发射监测试验研究了其力学参数劣化规律及损伤破坏演化特征。研究结果表明:泥质砂岩的单轴抗压强度σ、弹性模量E、黏聚力c、内摩擦角φ的劣化度与干湿循环次数正相关,而劣化速率与干湿循环次数负相关,围压延缓了其劣化过程,酸性环境则会加剧岩样的劣化。σ对于酸性干湿循环的敏感度最高,在不同pH值条件下力学参数与干湿循环次数均呈较强的对数关系。声发射振铃累计计数及能量演化特征可分为初始活跃期、稳定增长期和高峰陡增期,并且在稳定增长期表现出较为明显的突变破坏前兆。随着酸性干湿循环的耦合作用效应持续增强,RA-AF张拉裂纹信号持续下降,声发射定位事件特征由中部轴向聚集逐步演变为斜向随机分布,损伤破坏特征由张拉破坏向剪切破坏转变。基于声发射数据驱动的泥质砂岩损伤状态识别模型的综合识别准确率达到93.33%,振铃累计计数和最大能量特征贡献率为81.63%,表明所建模型可较为准确地识别损伤状态等级与声发射数据间的内在关联特征。This study aims to investigate the effects of wet-dry cycles caused by rainfall-evaporation and acid rain erosion on the stability of argillaceous sandstone slopes.It examines the degradation patterns of mechanical parameters and the evolution of damage and failure in argillaceous sandstone subjected to various acidic wet-dry cycles using uniaxial and triaxial compression tests and acoustic emission monitoring tests.The results indicate a positive correlation between the degradations degrees of uniaxial compressive strength(σ),elastic modulus(E),cohesion(c),and internal friction angle(φ)of argillaceous sandstone and the number of wet-dry cycles.Conversely,the degradation rate shows a negative correlation with the cycles.Confining pressure retards the degradation process,while acidic environments intensify the degradation of rock samples with σ being highly sensitive under acidic wet-dry cycles.Mechanical parameters exhibit a significant logarithmic relationship with the number of wet-dry cycles across different pH conditions.The acoustic emission ringing counts and energy evolution characteristics can be categorized into three phases:an initial active phase,a stable growth phase,and a peak rapid increase phase.Distinct precursors to abrupt failure are evident during the stable growth phase.The RA-AF tensile crack signals consistently decrease due to the strengthening effects of acidic wet-dry cycles.Additionally,the characteristics of acoustic emission localization events shift from a central axial cluster to an oblique random distribution,indicating a transition in damage from tensile to shear failure.The composite accuracy for identifying the damage state of argillaceous sandstone using an acoustic emission data-driven model achieved 93.33%.The ringing count and maximum energy features contributed 81.63%to this accuracy,highlighting the model’s ability to accurately capture the intrinsic correlation between damage state levels and acoustic emission data.

关 键 词：酸性干湿循环 泥质砂岩 声发射 劣化 特征识别 数据驱动 

分 类 号：TU458[建筑科学—岩土工程]