采矿与安全工程学报 ›› 2014, Vol. 31 ›› Issue (5): 788-794.

• 论文 • 上一篇    下一篇

加卸荷条件下胶结充填体声发射b值特征研究

  

  1. 1.北京科技大学金属矿山高效开采与安全教育部重点实验室,土木与环境工程学院,北京 100083; 2.江西理工大学工程研究院,江西 赣州 341000
  • 出版日期:2014-09-15 发布日期:2014-10-08
  • 作者简介:龚囱(1985—),男,江西省南昌县人,博士研究生,从事岩石力学与岩层控制方面的研究。 通信作者:李长洪 E-mail:lch@ustb.edu.cn Tel:13701252926
  • 基金资助:

    国家自然科学基金项目(51064010,50364012);国家重点基础研究发展计划(973)项目(2010CB731500)

Experimental study on b-value characteristics of acoustic emission of cemented filling body under loading and unloading test

  • Online:2014-09-15 Published:2014-10-08

摘要: 为认识胶结充填体在外界扰动下的响应特征,进行了单轴循环加卸载试验,研究了胶结充填体在加-卸载过程中声发射 值特征。试验结果表明:在胶结充填体压密阶段,声发射 值先减小后增大;在弹性阶段,声发射 值随应力的增大而有序下降;经多次加卸载后,当加载应力不断接近峰值应力时,声发射 值持续大幅度减小。在卸载阶段,胶结充填体具有明显的声发射事件。当卸载始于压密阶段时,声发射 值是逐渐增大的;当卸载始于弹性阶段时,声发射 值在小范围内波动;当卸载始于胶结充填体临界状态时,声发射 值呈现“台阶”状上升。声发射 值数值表现出的不同特征,说明在加卸载过程中微破裂处于动态演化之中。

关键词: 胶结充填体, 加载, 卸载, 声发射b值

Abstract: In order to study the response characteristics of cemented filling body under external disturbance, the studies have been carried out by virtue of uniaxial cyclic loading and unloading tests on cemented filling body, and the -value characteristics of acoustic emission (AE) of cemented filling body is examined. The results show that, during the compression phase, the b-value decreases firstly and then increases. By contrast, the b-value declines orderly as stress increases in elastic stage. After undergoing repeated loading and unloading, the -value reduces greatly as loading stress approaches to the peak stress. Similarly, The AE events are obvious in unloading process. The b-value increases gradually when unloading is started from compressing phase. And when unloading is started from elastic phase, the b-value fluctuates in a small range respectively. Finally, the -value appears step-increasing trend when unloading is started at critical state of cemented filling body. The different -value characteristics indicates that the occurrence of micro crack is in dynamic evolution during loading and unloading process.

Key words: cemented filling body, loading, unloading, -value of acoustic emission