高轴压和围压共同作用下矽卡岩受频繁动态扰动时的动力学特性  

Dynamic characteristics of skarn subjected to frequent dynamic disturbance under combined action of high axial compression and confining pressure

作　　者：王春[1,2] 唐礼忠 程露萍[1,3] 陈源 刘涛[3] 韦永恒[3] WANG Chun;TANG Li-zhong;CHENG Lu-ping;CHEN Yuan;LIU Tao;WEI Yong-heng(School of Energy Science and Engmeenng,Henan Polytechnic University,Jiaozuo,Henan 454000,China;The Collaborative Innovation Center of Coal Safety Production of Henan,Henan Polytechnic University,Jiaozuo,Henan 454000,China;School of Resources &Safety Engineering,Central South University,Changsha.Hunan.410083,China)

机构地区：[1]河南理工大学能源科学与工程学院,河南焦作454000 [2]河南理工大学煤炭安全生产河南省协同创新中心,河南焦作454000 [3]中南大学资源与安全工程学院,湖南长沙410083

出　　处：《岩土力学》2018年第12期4537-4546,共10页Rock and Soil Mechanics

基　　金：河南省高校重点科研项目(No.18A440014);河南理工大学博士基金项目(No.672707);国家自然科学基金项目(No.51604093);supported by the Key Scientific Research Project of Colleges and Universities in Henan Province(18A440014);the Doctoral Foundation of Henan Polytechnic University(672707);the National Natural Science Foundation of China(51604093)

摘　　要：以冬瓜山铜矿深部出矿进路附近的矽卡岩为研究对象,采用改进的SHPB试验系统,进行高轴压和围压共同作用下受频繁动态扰动时深部矽卡岩动力学特性的研究。研究结果表明:预加载的高轴压和围压促使岩石内部微裂纹闭合,致使冲击荷载作用时动态应力-应变曲线初始阶段无下凹现象,即无压密阶段;峰值应力后,当岩样内部存储的弹性力大于卸荷时的冲击荷载时,出现应变减小的回弹现象,否则压缩应变一直增大至岩样破碎;累计扰动冲击次数随围压增大递增,随轴压增大递减,且增减率受围压、轴压大小的影响;动态变形模量、动态峰值应力随扰动冲击次数增加而减小,但最大应变及动态峰值应变增加;动态均值强度随轴压增大而减小,随围压增大先减小后增大;岩石动态变形过程中伴随着弹性变形,产生的回弹应变总体上随扰动冲击次数的增加呈先增大后减小的趋势发展。Taking the skarn specimens extracted near the deep ore drift in Dongguashan copper mine as the research object, a modified split Hopkinson pressure bar(SHPB) system was used to investigate dynamic characteristics of deep skarn under the combined action of high axial pressure and confining pressure under frequent dynamic disturbance. The results show that internal microcracks in specimens were closed due to high pre-loaded axial pressure and confining pressure, which results in no concave phenomenon at the initial stage of dynamic stress-strain curves during the impact load, i.e. no compaction stage. After peak stress, the phenomenon of reduced strain rebound occurs when the elastic force stored in the specimen is greater than the impact load during unloading. Otherwise, the compressive strain increases until the specimen breaks. The accumulative impact disturbance times rises while with increasing confining pressure, and it reduces due to the increased axial compression. Furthermore, the growth or decreasing rate is influenced by the confining pressure and axial pressure. The dynamic deformation modulus and peak stress decrease with the increase of impact disturbance times, but the maximum strain and dynamic peak strain grow up. Moreover, the average of dynamic strength has been cut down with the rising axial pressure, but it decreases firstly and then increases with the increase of confining pressure. The dynamic deformation of rock is accompanied by elastic deformation, the strain rebound generally increases firstly and then decreases with increasing impact disturbance times on the whole.

关 键 词：高轴压 围压 动态扰动 变形特征 冲击次数 变形模量 

分 类 号：TU452[建筑科学—岩土工程]