受载混凝土内部应变及声发射特征研究  

Study on internal strain and acoustic emission characteristics of loaded concrete

作　　者：汪皓[1] 王笑然[1] 刘晓斐[1] 李学龙[1] 湛堂啟 

机构地区：[1]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《工矿自动化》2016年第10期74-78,共5页Journal Of Mine Automation

基　　金：国家自然科学基金项目(51574231);教育部科学技术研究项目(113031A);中国矿业大学第七批优秀创新团队建设项目(2014ZY001)

摘　　要：为了研究混凝土试样破裂失稳过程中内部裂隙演化规律,对预埋应变砖的混凝土试样进行单轴压缩实验,研究了混凝土试样内部应变随时间的变化规律,测试并分析了试样受载破裂演化过程中的声发射信号特征,得出结论:在压密阶段,混凝土不同方向的应变量均较小,声发射计数较低;在裂隙稳定扩展阶段,试样内部应变稳定增加,不同方向的局部应变量有明显不同,声发射信号也呈现稳定增长趋势;当混凝土出现局部快速破裂时,会出现应变的突增及声发射信号激增;在临界失稳前,局部变形量快速增加,声发射信号也急剧增加;试样破裂时,各个方向的局部应变量及声发射脉冲数均达到峰值。In order to study interior crack evolution rules in rupture and instability process of concrete specimen,uniaxial compression experiment of concrete specimen embedded with strain brick was conducted,variation rule of internal strain of the concrete specimen with time was studied,and acoustic emission signal characteristics of the samples in the evolution process of loading and fracture were measured and analyzed.The following conclusions are obtained：in the compaction stage,variables in different directions are small and acoustic emission count is low;in the stable crack propagation stage,the internal strain of samples increase stably,local strains in different directions are significantly different and acoustic emission signals also show a steady growth trend;when local fast rupture of concrete appears,strain and acoustic emission signal both increase suddenly;before the critical instability,local deformation increases rapidly and the acoustic emission signals increase dramatically;when fracture appears,local strains and acoustic emission pulse number in all directions reaches the peak.

关 键 词：混凝土 裂隙演化 内部应变 声发射 

分 类 号：TD311[矿业工程—矿井建设]