静态—准静态加载下含裂隙类岩材料破断试验及声发射特性分析  

Fracture Test of Rock-like Materials with Cracks and Analysis of Acoustic Emission Characteristics at Static-Quasi-Static Loading Rates

作　　者：郭婧宇 蒲成志 贺桂成 李益龙 杨少峰 曾佳君 GUO Jingyu;PU Chengzhi;HE Guicheng;LI Yilong;YANG Shaofeng;ZENG Jiajun(School of Resource Environment and Safety Engineering,University of South China,Hengyang 421001,Hunan,China)

机构地区：[1]南华大学资源环境与安全工程学院,湖南衡阳421001

出　　处：《黄金科学技术》2020年第6期877-884,共8页Gold Science and Technology

基　　金：国家自然科学基金项目“水—力耦合作用下卸荷诱导的裂隙体破断实验与灾变机理研究”(编号:51704168);中国博士后科学基金项目“单轴压缩下渗透压动态传递—稳态作用的裂隙体断裂破坏试验与研究”(编号:2016M602417);湖南省自然科学基金项目“渗流场长时稳定作用的裂隙体破断实验与机理研究”(编号2019JJ50528)联合资助。

摘　　要：为了探究加载速率和裂隙倾角复合影响的裂隙体类岩石材料破断规律,对含0.1 mm预制裂隙的类岩材料进行静态到准静态的不同加载速率单轴压缩试验,基于声发射测试技术,分析含预置裂隙类岩材料起裂强度规律。结果表明:相同加载速率下,峰值强度随预制裂隙倾角增大呈现先减小后增大的变化趋势,倾角为45°时最小,裂隙倾角相同时,裂隙体峰值强度随加载速率的增大而增大;准静态加载范围内存在一个临界加载速率即2.0×10-4 s-1,使得加载速率强化效应不再显著;低频信号占比逐渐升高,可作为裂隙体失稳前兆信息;裂隙倾角相同时,裂隙体起裂应力水平随加载速率的增大而增大,相同加载速率下,裂隙体起裂应力水平随倾角的增大而增大。In subways,tunnels and other projects,the loading rate effect produced by short-time,high-strength excavation is one of the main factors of engineering disasters.With the widening of demand and the deepening of research,it is of great significance for the safety protection and stability evaluation of rock engineering to carry out studies on the mechanical effects of loading rate and the influence of crack dip angle related to time factors.In order to investigate the fracture law of fractured rock-like materials combined with loading rate and fracture dip angle,RMT-150B rock mechanics testing machine was used to perform static to quasi-static 4-level loading rate uniaxial compression of rock-like materials with 0.1 mm prefabricated cracks.Based on acoustic emission testing technology,the initiation strength law of rock-like materials with preset cracks and the dynamic frequency domain change characteristics of rock mass fractures under the combined action of loading rate and crack dip angle was analyzed.The main research results show that:Under the same loading rate,prefabricated cracks with different dip angles have different degrees of damage to the compressive strength of rock-like specimens,and the peak strength shows a trend of decreasing first and then increasing with the increase of the prefabricated crack dip angle,and the minimum angle is 45°.When the fracture inclination angle is the same,the peak strength of the fracture body increases with the increase of the loading rate.There is a critical loading rate in the quasi-static loading range,so that the loading rate strengthening effect is no longer significant,that is,the growth of the fissure body basically stagnate after reaching a certain value.This critical loading rate is around 2.0×10-4 s-1.Acoustic emission activity begins to be apparently active after the end of the micro-crack closure phase in the specimen.A large number of micro-cracks initiate and penetrate each other to form macrocracks.The AE energy rate is most active around the peak.Under

关 键 词：声发射 加载速率 预制裂隙 类岩材料 裂隙倾角 频域特征 起裂应力水平 

分 类 号：TU45[建筑科学—岩土工程]