受加载速率影响花岗岩破坏试验及前兆研究  

Study on failure test and precursor of granite affected by loading rate

作　　者：殷志强[1,2,3] 韩宁 齐潮 张驰 张永坤[1,2,3] 刘浩 章新生[4] 曹坤 YIN Zhiqiang;HAN Ning;QI Chao;ZHANG Chi;ZHANG Yongkun;LIU Hao;ZHANG Xinsheng;CAO Kun(Key Laboratory of Safe and Effective Coal Mining Ministry of Education,Anhui University of Science and Technology,Huainan 232001,China;School of Mining Engineering,Anhui University of Science and Technology,Huainan 232001,China;Coal Mine Safety Mining Equipment Innovation Center of Anhui Province,Anhui University of Science and Technology,Huainan 232001,China;The Construction Engineering Company of CTCE Group,Hefei 230031,China)

机构地区：[1]安徽理工大学煤矿安全高效开采省部共建教育部重点实验室,安徽淮南232001 [2]安徽理工大学矿业工程学院,安徽淮南232001 [3]安徽理工大学安徽省煤矿安全采掘装备制造业创新中心,安徽淮南232001 [4]中铁四局集团建筑工程有限公司,安徽合肥230031

出　　处：《中国矿业》2025年第3期194-204,共11页China Mining Magazine

基　　金：国家自然科学基金项目资助(编号:52274070)。

摘　　要：为研究受加载速率效应影响深部硬岩巷道围岩失稳破坏过程中各阶段破裂响应机制,对花岗岩开展了五种不同加载速率的试验并配以声发射监测系统,分析了变加载速率下花岗岩试件各应力阶段的破裂演化特征、力学参数、声发射参数的变化规律,并基于声发射振幅集中度曲线Γ的变化规律,获得花岗岩失稳破坏前兆的预警信息。结果表明:加载速率越大,试件破坏所需时间越短且破坏越烈;试件峰值强度,弹性模量与加载速率呈现出良好的正相关性,当加载速率超过0.1kN/s时二者增幅均减缓,峰值强度增幅由26.00%下降至6.50%,弹性模量增幅由35.60%下降至12.00%,峰值应变与加载速率呈现出良好的负相关性;声发射活动度呈现明显的阶段性增长,AE振铃计数呈现出指数增长,AE能量信号逐渐由“孤震型”向“群震型”转化;声发射b值随加载时间总体呈现出“W”型变化,试件破坏时声发射b值随加载速率的升高而降低,由0.47(0.02kN/s)降至0.30(0.50kN/s),该现象表明加载速率越大,试件的破裂尺度越大,试件破坏的越彻底;RA-AF散点数据在各应力阶段分布特征表明,加载速率越大,试件内部剪切裂纹随发育越好;振幅集中度曲线Γ在震荡上升阶段和骤然上升阶段之间的斜率突变点定义为变加载速率下花岗岩试件的临界损伤因子,该点可作为岩石失稳破坏前的预警信息。In order to study the fracture response mechanism of each stage in the process of instability and failure of the surrounding rock of the deep hard rock roadway affected by the loading rate effect,five tests with different loading rates are carried out on the granite,and the variation law of the fracture evolution characteristics,mechanical parameters and acoustic emission parameters of granite specimens at each stress stage under variable loading rate is analyzed,and the early warning information of granite instability failure precursors is obtained based on the variation law of the Γ of the acoustic emission amplitude concentration curve.The results show that the larger the loading rate,the shorter the time required for the specimen to fail and the more severe the failure.When the loading rate exceeds 0.1 kN/s,the growth rate of both of them slows down,the increase of peak strength decreases from 26.00% to 6.50%,and the increase of elastic modulus decreases from 35.60% to 12%,showing a good negative correlation between peak strain and loading rate.The AE activity showes an obvious phased increase,the AE ringing count showes an exponential increase,and the AE energy signal gradually changes from“solitary seismic type”to“group seismic type”.The b value of AE generally showes a“W”pattern with the loading time,and the b value of AE decreased with the increase of the loading rate when the specimen is damaged,from 0.47(0.02 kN/s)to 0.30(0.50 kN/s),which indicates that the larger the loading rate,the larger the rupture scale of the specimen and the more complete the damage of the specimen became.The distribution characteristics of RA-AF scatter data in each stress stage show that the larger the loading rate,the better the internal shear crack development of the specimen.The amplitude concentration curve Γ the abrupt change point of slope between the oscillating rising stage and the abrupt rising stage is defined as the critical damage factor of granite specimens under variable loading rate,which can be us

关 键 词：花岗岩 加载速率效应 破裂演化特征 声发射 破坏前兆 

分 类 号：TD32[矿业工程—矿井建设]