摘要
为了克服巷(隧)道岩爆破裂演化及监测研究的不足,结合全过程超声波平测法监测,开展了花岗岩试样单面约束情况下的双轴压缩试验,得出了硬岩超声波平测法均质度及波速的确定方法,分析和探讨了硬岩层爆机理及超声波平测波形规律。结果表明,爆裂体呈现明显层裂现象,岩爆核心位于临界爆裂前的临空面内部应力集中区;平测波形可以揭示硬岩层爆的孕育演化进程,在加载过程中超声波平测波速总体呈现阶段性下降趋势,后续波到达时间在加载前期和中期总体变动不大,到了后期明显增加,后续波波幅在加载过程中总体呈现下降趋势,爆裂前波幅有所增加;探讨了超声波平测法在硬岩层爆现场监测中的应用,可以根据平测法波形、波速的变化情况预测硬岩层爆和实现对围岩的无损监测,可进一步通过损伤变量揭示其损伤演化进程并实现预测。
To overcome the shortage of study on fracture evolution and monitoring of rockburst in roadways(tunnels), biaxial compression comparative tests are carried out on rectangular granite samples under the constraint of one side by monitoring the whole process using ultrasonic plane testing method. The method of determination of homogeneity and wave velocity is obtained. The mechanism of rockburst and the regularity of ultrasonic wave waveform are analyzed and discussed. The results show that the hard rock presented obvious layer burst phenomenon and the core of rockburst is located in the inner stress concentration zone before the critical bursting. The evolution process of stratified burst of hard rock can be revealed by means of the waveform of ultrasonic plane testing method; the velocity of ultrasonic wave is decreasing in the process of loading; arrival time of the subsequent wave has not obvious change in the earlier stage and metaphase periods; however, the arrival time of the later period is obviously increasing; and the subsequent wave amplitude is generally decreasing in the loading process; the wave amplitude is increasing before the burst. The application of ultrasonic plane testing method in the field of hard rock monitoring is discussed, stratified burst of hard rock can be predicted based on the variation of waveform and wave velocity and nondestructive monitoring of surrounding rock is realized; the damage evolution process and prediction can be further revealed by the damage variables.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第S2期203-209,共7页
Rock and Soil Mechanics
基金
山东省自然科学基金项目(No.ZR2015EL016)
山东理工大学青年教师发展支持计划经费(2012年)~~
关键词
硬岩
层爆
超声波平测法
双轴压缩试验
波速
hard rock
stratified burst
ultrasonic plane testing method
biaxial compression test
wave velocity
