花岗岩破裂过程中“声发射-电阻率-波速”演化特征研究及工程探测应用  

Characterisation of“acoustic emission-resistivity-wave velocity”evolution in granite rupture and application to engineering detection

作　　者：纪洪广[1,2] 付桢 张月征 张春瑞[1,2] 陈东升 JI Hongguang;FU Zhen;ZHANG Yuezheng;ZHANG Chunrui;CHEN Dongsheng(Beijing Key Laboratory of Urban Underground Space Engineering,University of Science and Technology Beijing,Beijing 100083,China;National Engineering Research Center of Deep Shaft Construction,Beijing 100013,China)

机构地区：[1]北京科技大学城市与地下空间北京市重点实验室,北京100083 [2]矿山深井建设技术国家工程研究中心,北京100013

出　　处：《中国矿业大学学报》2024年第5期872-888,共17页Journal of China University of Mining & Technology

基　　金：国家重点研发计划项目(2023YFC2907401,2023YFC2907403);国家自然科学基金项目(52278326)。

摘　　要：为探明脆性岩石破坏过程中裂纹与声发射、电阻率和波速之间的协同演化规律,通过设计并开展花岗岩单轴加载条件下的联合测试试验,揭示了岩石受载裂纹演化过程中3种信号的响应特征,并通过工程实测,获得了地层探测时电阻率与超声波波速的变化规律.试验结果表明:脆性岩石破坏是由“低能稳定无序状态”向“高能非稳定有序状态”转变的过程,裂纹演化则是由随机的无序扩展转变为条带式的集中有序破裂,具有自组织临界特征;脆性岩石声发射能量概率密度呈现线性分布,其破坏能量演化过程满足幂律分布,加载后期局部高应力水平下的能量幂律分布曲线逐渐向全过程幂律分布曲线逼近,表明高能非稳定状态的岩石更容易产生突发性破坏;岩石破裂过程中的电阻率、超声波波速和声发射随裂纹演化呈阶段性响应特征,岩石受载进入裂纹稳定和非稳定扩展阶段后,宜采用波速损伤变量和声发射损伤变量描述岩石损伤特性,综合考虑裂纹体积应变、声发射、电阻率和波速能准确识别岩石的峰前特征应力;通过工程实测超声波的变化规律,将地层划分为完整、较完整、破碎和极破碎4个等级,破碎含水地层具有低波速、低电阻率特征,电阻率与波速相互验证、互为补充.此方法可为深部地下工程建设围岩质量评价、岩体损伤实时监测提供理论依据.To investigate the coordinated evolution of cracks,acoustic emission,resistivity,and wave velocity during the brittle rock failure process,designed and conducted a series of uniaxial loading tests on granite,revealing the response characteristics of these three signals during crack evolution in rock under loading,through field measurements,the change laws of resistivity and wave velocity during geological exploration were also obtained.The results show that the failure of brittle rock is a process of transition from a“low-energy stable disordered state”to a“high-energy unstable ordered state”,and the crack evolution transforms from random disordered expansion to concentrated and ordered banding,exhibiting self-organized critical characteristics.The probability density of acoustic emission energy in brittle rock exhibits a linear distribution,and the energy evolution during failure follows a power-law distribution.The power-law distribution curve gradually approaches the overall power-law distribution in the later stage of loading under high local stress levels,indicating that rocks in a highenergy unstable state are more prone to sudden failure.The electrical resistivity,ultrasonic wave velocity,and acoustic emission show staged response characteristics along with crack evolution during the rock failure process.After the rock enters the stable and unstable crack expansion stages,the wave velocity damage variable and acoustic emission damage variable can be used to describe the rock damage characteristics.Comprehensively considering the crack volumetric strain,acoustic emission,electrical resistivity,and wave velocity can accurately identify the characteristic stress before the peak strength of rock.Through field measurements of ultrasonic wave changes,the formation can be divided into four levels:intact,relatively intact,fractured,and highly fractured.Fractured and water-bearing formations exhibit low wave velocity and low electrical resistivity characteristics.Electrical resistivity and wave velocity can

关 键 词：裂纹演化 电阻率 超声波波速 声发射 bI值 自组织临界点 

分 类 号：TD85[矿业工程—金属矿开采]