含水率对岩石电荷感应信号影响规律研究  

Effects of water content on the charge induced signal of rock

作　　者：郑文红[1] 施天威 潘一山 罗浩 吕祥锋 ZHENG Wen-hong;SHI Tian-wei;PAN Yi-shan;LUO Hao;LÜ Xiang-feng(School of Mechanics and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China;School of Environment,Liaoning University,Shenyang,Liaoning 110036,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [2]辽宁大学环境学院,辽宁沈阳110036 [3]北京科技大学土木与资源工程学院,北京100083

出　　处：《岩土力学》2022年第3期659-668,共10页Rock and Soil Mechanics

基　　金：国家重点研发计划资助项目(No.2017YFC0804208)。

摘　　要：水是诱发矿井灾害的主要因素之一,研究水-岩相互作用下的岩石破坏电荷信号,可丰富矿井水引起灾害的监测方法。为研究含水率对岩石破坏电荷感应信号的影响规律,基于损伤理论推导了岩石损伤破坏力-电耦合模型,得到了感应电荷量与岩石力损伤和水损伤的理论关系。利用自主研制的电荷感应信号数据采集系统,对不同含水率条件下的岩石试样进行了单轴压缩电荷感应信号监测试验,分析了水对岩石力学性质和岩石破坏过程中各阶段电荷感应信号的影响规律,并对含水率影响感应电荷产生的机制进行了讨论。结果表明:岩石变形破坏过程中的电荷感应信号与岩石的损伤程度有关,累积感应电荷量与感应电荷总量的比值可以表示岩石在水和力作用下的损伤量,且含水率越高,试样越易在较低的应力下产生大量的电荷感应信号。不同含水率岩石的宏观破坏特征明显不同,随着含水率升高,岩石的抗压强度降低,裂隙发育,岩石破坏形式由单剪式破坏向张拉和剪切混合破坏转变。电荷感应信号分布形态上,含水率的升高使得高幅值电荷簇数增加,并向弹性阶段发展,且高幅值电荷感应信号主要分布在弹性阶段后期和塑性阶段。感应电荷量上,随着含水率的升高,弹性阶段的感应电荷释放量占比逐渐增大,塑性阶段占比逐渐减小,两阶段的感应电荷量之和占试样变形破坏过程中产生感应电荷总量的90%以上。水通过弱化岩石颗粒和渗透压作用,使岩石在较低应力下产生或扩展裂隙,感应电荷信号更丰富。Water is one of the main factors that induce mine disasters. Monitoring methods for disasters caused by mine water can be extended by studying the charge induction signal of rock deformation and failure under the interaction between water and rock. In order to study the effect of water content on the charge induced signal in the process of rock deformation and failure, we derive an electrostatic-mechanical coupling model based on the damage theory, and obtain the theoretical relationship among the amount of induced charge, the rock mechanical damage and the water-induced damage. Using the self-developed charge-induced signal acquisition system, we carried out the uniaxial compressional charge-induced signal monitoring on the rock samples with different water contents. We analyze the effects of water on the mechanical properties of rock, as well as on the charge induced signal in each stage of rock failure process, and discuss the mechanism by which water content affects the generation of induced charges. The results show that:(1) The charge induced signal in the process of rock deformation and failure is related to the damage degree of rock.The ratio of the cumulative induced charge to the total induced charge can indicate the damage level of the rock under the action of water and force. The higher the content of water is, the easier the samples that can generate a large number of charge-induced signals under lower stress.(2) The macroscopic failure characteristics of rock samples are obviously different with different water content.With the increase of water content, the compressive strength of rock samples decrease, the cracks develop, and the failure mode of the rock samples changes from single shear failure to tension and shear mixed failure.(3) In terms of the distribution of the charge-induced signal, the increase of water content increases the number of high-amplitude charge clusters, and makes them developed into the elastic stage. The high-amplitude charge-induced signals are mainly distributed in the la

关 键 词：含水率 电荷感应信号 损伤 力-电耦合模型 累积感应电荷量 

分 类 号：TU451[建筑科学—岩土工程]