干湿循环节理砂岩单轴压缩声发射演化特征  

Acoustic Emission Evolution Characteristics of Jointed Sandstone at Drying-Wetting Damage under Uniaxial Compression

作　　者：王桂林[1,2] 杨证钦 张亮[3] 孙帆 WANG Gui-lin;YANG Zheng-qin;ZHANG Liang;SUN Fan(College of Civil Engineering,Chongqing University,Chongqing 400045,China;National Centre for Local Joint Engineering Research on Environmental Geological Hazards in Reservoir Areas,Chongqing 400045,China;School of Architecture and Civil Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学库区环境地质灾害防治国家地方联合工程研究中心,重庆400045 [3]西安科技大学建筑与土木工程学院,西安710054

出　　处：《长江科学院院报》2023年第2期81-86,94,共7页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(51978106)。

摘　　要：干湿循环对岩石造成不可逆的累积损伤,而岩石的变形破坏过程伴随着明显的声学特征。为探讨干湿循环后节理砂岩变形破裂机理,通过开展节理砂岩室内单轴压缩试验,采用声发射测试技术监测岩样损伤破坏的声学数据,研究历经0、1、5、10、15、20次干湿循环作用后的完整、单节理、双节理砂岩岩样在变形破裂过程中声发射参数的演化特征。结果表明:随着干湿循环次数的增加,砂岩岩样峰后塑性特征逐渐增强,声发射活动表现存在微弱、增强、陡增、剧烈4个阶段;随着干湿循环次数的增加,节理岩样声发射剧烈活动阶段的持续时间、累计振铃计数的降幅以及变形破坏过程中的声发射b值均呈逐步增大的趋势;各种干湿循环次数情况下完整岩样的声发射b值均大于节理岩样。研究成果可为干湿循环下节理岩体变形破坏机理研究提供有益的参考。Dry-wet cycles cause irreversible cumulative damage to rocks, and the deformation and failure process of rock is accompanied by obvious acoustic characteristics.In order to explore the deformation and failure mechanism of jointed sandstone after dry-wet cycles, we monitored the acoustic data of damage and failure of jointed sandstone specimens under indoor uniaxial compression test by acoustic emission(AE),and further examined the evolution characteristics of acoustic emission parameters of intact single-jointed and double-jointed sandstone specimens in the deformation and failure process after different dry-wet cycles(0,1,5,10,15 and 20 cycles).Results elucidated that with the proceeding of dry-wet cycles, the post-peak plastic characteristics of sandstone rock specimens gradually increased, and the AE activities undergone weak, enhanced, steep increase, and intense stages;the duration of violent phase of acoustic emission, the decrease of cumulative ringing count, and the b value of AE in the process of deformation and failure gradually increased.The b values of AE of intact rock samples at any dry-wet cycle were larger than those of jointed rock specimens.The research findings offer reference for researching the deformation and failure mechanism of jointed rockmass under dry-wet cycles.

关 键 词：节理砂岩 干湿循环 单轴压缩 声发射监测 声发射b值 

分 类 号：TU45[建筑科学—岩土工程]