Strength weakening effect of high static pre-stressed granite subjected to low-frequency dynamic disturbance under uniaxial compression  

单轴压缩下高静预应力花岗岩受低频动力扰动的强度弱化效应

作　　者：Wu-xing WU Feng-qiang GONG Quan JIANG 伍武星;宫凤强;江权(东南大学教育部爆炸与冲击安全防护工程研究中心(ERCSPEIME),南京211189;东南大学土木工程学院,南京211189;中国科学院岩土力学研究所岩土力学与岩土工程国家重点实验室,武汉430071)

机构地区：[1]Engineering Research Center of Safety and Protection of Explosion&Impact of Ministry of Education(ERCSPEIME),Southeast University,Nanjing 211189,China [2]School of Civil Engineering,Southeast University,Nanjing 211189,China [3]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第7期2353-2369,共17页中国有色金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No.42077244);the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences (No.Z020005);the Fundamental Research Funds for the Central Universities of Southeast University,China (No.2242021R10080)。

摘　　要：This study aimed to elucidate the strength weakening effect of high static pre-stressed rocks subjected to low-frequency disturbances under uniaxial compression.Based on the uniaxial compressive strength(UCS)of granite under static loading,70%,80%,and 90%of UCS were selected as the initial high static pre-stress(σ_(p)),and then the pre-stressed rock specimens were disturbed by sinusoidal stress with amplitudes of 30%,20%,and 10%of UCS under low-frequency frequencies(f)of 1,2,5,and 10 Hz,respectively.The results show that the rockburst failure of pre-stressed granite is caused by low-frequency disturbance,and the failure strength is much lower than UCS.When theσp or f is constant,the specimen strength gradually decreases as the f or σ_(p) increases.The experimental study illustrates the influence mechanism of the strength weakening effect of high static pre-stress rocks under low-frequency dynamic disturbance,that is,high static pre-stress is the premise and leading factor of rock strength weakening,while low-frequency dynamic disturbance induces rock failure and affects the strength weakening degree.研究高静预应力岩石在单轴压缩下受低频动力扰动的强度弱化机制。根据花岗岩在静态加载下的单轴抗压强度(UCS),选取70%、80%和90%的UCS作为初始高静预应力(σ_(p)),然后对高静预应力岩石试样施加应力幅值分别为30%、20%和10%UCS的正弦波扰动荷载,其相应低频扰动频率(f)分别为1、2、5和10 Hz。结果表明,高静预应力花岗岩受到低频扰动发生岩爆破坏,其破坏强度远低于静载条件下的单轴抗压强度。当σ_(p)或f一定时,花岗岩试样的抗压强度随f或σ_(p)的增加而逐渐降低。本研究阐明了低频动力扰动下高静预应力岩石强度弱化效应的影响机理,即高静预应力是岩石强度弱化的前提和主导因素,而低频动力扰动诱发岩石破坏并影响强度弱化程度。

关 键 词：deep rock high static pre-stress low-frequency dynamic disturbance strength weakening effect uniaxial compression ROCKBURST 

分 类 号：TU45[建筑科学—岩土工程]