水力耦合作用下含三维裂隙类岩石材料的破裂力学行为及声发射特征  

Fracture mechanical behavior and AE characteristics of rock-like material containing 3-D crack under hydro-mechanical coupling

作　　者：郭孔灵 杨磊[1] 盛祥超 梅洁[1] 李邦翔[1] 张波[3] 杨为民[1] 宋光啸 GUO Kong-ling;YANG Lei;SHENG Xiang-chao;MEI Jie;LI Bang-xiang;ZHANG Bo;YANG Wei-min;SONG Guang-xiao(Research Center of Geotechnical and Structural Engineering,Shandong University,Jinan,Shandong 250061,China;Huadong Engineering Corporation Limited,Power China,Hangzhou,Zhejiang 310014,China;School of Civil Engineering,Shandong University,Jinan,Shandong 250061,China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]中国电建华东勘测设计研究院有限公司,浙江杭州310014 [3]山东大学土建与水利学院,山东济南250061

出　　处：《岩土力学》2019年第11期4380-4390,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金青年项目资助（No.51509146）;国家自然科学基金面上项目资助（No.51879151,No.51879148)~~

摘　　要：水力耦合作用下裂隙岩体的破裂力学行为及声发射特征是关系到地下工程安全建设与灾变预测预警的关键问题。利用水泥砂浆材料及声发射技术开展了室内压缩破裂试验,研究了无水及水力耦合条件下含三维裂隙试件的破裂模式、力学特性、声发射特征以及水压和裂隙倾角的影响,分析了声发射信号主频特征随岩体破裂状态的变化规律。试验结果表明:随裂隙倾角增大,试件破裂模式经历了张拉为主-拉剪复合-剪切为主的转变过程;水压增大增强了试件张拉破裂模式,而剪切破裂模式在一定程度上被削弱;随水压升高,起裂应力、损伤应力和峰值强度均持续降低,水压对起裂应力及峰值强度的影响程度存在阈值(4 MPa);试件破裂过程中声发射撞击率变化呈现明显阶段性特征,从而为起裂和损伤应力判定提供了依据;试件不同破裂状态下的声发射信号呈现不同主频特征,相对高、中、低频波的主频值域区间具有非连续性,低频和高频信号占比与试件破裂状态存在对应关系,因此可为岩体破裂状态的预测预警提供参考信息。For the construction safety of underground engineering and prediction & warning of disasters, the fracture mechanical behavior and acoustic emission(AE) characteristics of fractured rock masses under hydro-mechanical coupling condition are key concerning problems. This study carries out compression failure experiments with the cement mortar material and AE technique, and investigates the failure modes, mechanical properties and AE characteristics of specimens containing 3-D crack under dry and hydro-mechanical coupling condition. The influences of crack dip angle and water pressure on the specimen failure and mechanical behavior, as well as the relation of dominant frequency characteristics of AE signals with the specimen failure status are analyzed. The experimental results indicate that the failure mode of specimen changes from tensile-dominant mode to tensile-shear mixed mode and finally shear-dominant mode as the crack dip angle increases. High water pressure enhances the tensile failure mode of specimens, while the shear failure mode is weakened to some extent. With the increase of water pressure, the crack initiation stress, damage stress and the peak strength of specimens decrease continuously, and the influence of water pressure on the initial stress and peak strength exhibits a threshold effect(4 MPa). The AE hit rate during the failure process of specimens presents an evident stage characteristic, which provides a reference base for the adjudgment of crack initiation and damage stress. Additionally, the AE signals exhibit different dominant frequency characteristics at different failure statuses of specimens, and the dominant frequency ranges of relatively high, intermediate and low frequency signals are discontinuous. The proportions of relatively-low-frequency and relatively-high-frequency signals correspond to different failure statuses of specimens, which can provide references for the rock mass failure prediction and warning.

关 键 词：水力耦合 三维裂隙 声发射 破裂模式 力学特性 主频特征 

分 类 号：TU452[建筑科学—岩土工程]