水岩耦合演化自然电场近源效应与临灾前兆  

Near-source effect of natural electric field in water-rock coupling evolution and its imminent disaster precursors

作　　者：刘静[1,2] 刘盛东[2] 王勃[2] 路拓 刘志新[1] LIU Jing;LIU Shengdong;WANG Bo;LU Tuo;LIU Zhixin(School of Resource and Earth Science, China University of Mining and Technology, Xuzhou 221116, China;State Key Laboratory of Deep Geomechanics & Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China;School of Geology and Environment, Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [3]西安科技大学地质与环境学院,陕西西安710054

出　　处：《煤炭学报》2022年第3期1286-1295,共10页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(41804106,41974149,41974128)。

摘　　要：水岩耦合演化是重大水害防控面临的核心科学问题之一。在全空间地电场探测中,自然电场可指示水体流向且对渗流演化行为的时域响应更超前,将其与激励电场、感应电场对物性的空间表征能力相结合,可提升探测的时空精度、获取水岩耦合演化监测及临灾预警的新突破。在裂隙岩体渗流、破碎岩体渗流等非饱和渗流及突变过程中,鉴于自然电场受流动电位控制且与水岩耦合演化、尤其是过水区的演化密切相关,故把在自然电场全空间监测工作中出现的、水流充分接近测点(含覆盖)时诱发的自然电场异常响应定义为一种近源效应,其主要特征为:①不存在过水事件时,自然电位随水流向测点的靠近而攀升、随水流与测点的远离而下降;②存在过水事件时,自然电位随水流向测点的靠近而攀升、随水流覆盖测点而出现相位突变(相对其他测点而言)和负向跳变、而后恢复攀升趋势但最终随着水流与测点的远离而再次下降;③因裂隙发育的非均质性,同一条测线上往往只有部分测点发生过水事件,这可根据自然电位的相位突变、负向跳变及视电阻率(或电阻率)图中的低阻演化等综合响应特征予以识别。利用自然电场法与直流电阻率法的并行探测关键技术,可实现地下水渗流状态及观测系统过水事件的有效判识;由此再对自然电位与直流电阻率数据进行耦合分析,由此实现对导水通道及富水区演化特征的精细解释和对水岩耦合演化趋势的超前预测,为矿井、隧道、地铁及其他地下空间工程中的重大水害防控提供有效方法。The coupled evolution of water and rock is one of the core problems in major water hazards prevention.In the whole-space geoelectric field detection,the natural electric field can be used to track water flow direction and its response is more advanced in time domain.As long as these advantages be combined to the spatial characterization capabilities of the primary electric field and the induced electric field for physical properties,the temporal and spatial accuracy of geoelectric field detection can be improved and some new breakthroughs in water-rock coupling evolution monitoring and emergency warning can be made.In the process of unsaturated seepage and its mutation,such as fractured rock mass seepage and broken rock mass seepage,the natural electric field is controlled by the streaming potential and is closely related to the evolution of water-rock coupling,including the water-passing area evolution.Therefore,the abnormal response of the natural electric field is defined as a near-source effect,induced by water approaching to the measuring point which appears in the whole-space monitoring.Its main features are as follows:①without water-passing event,the self-potential rises as the water approaches the measuring point,and decreases as the water moves away.②With water-passing event,the self-potential increases as water approaches the measuring point,falls as water covers the measuring point with the phase mutation(compared to other measuring points),and then resumes the upward trend,but finally decreases again as water moves away.③Due to the heterogeneity of fracture,only part of the measuring points meet water-passing events on the same survey line,which can be identified according to the self-potential falling characteristics and phase mutation,combining to the low resistance evolution characteristics in the apparent resistivity profile or resistivity profile.With the parallel detection technology of self-potential method and DC resistivity method,both the groundwater seepage state and the water-passing

关 键 词：水岩耦合 自然电场 全空间 水害防控 地电场监测 

分 类 号：TD74[矿业工程—矿井通风与安全] P631[天文地球—地质矿产勘探]