基于AE的煤岩破裂与动态失稳特征实验及综合分析
来兴平1，2，张勇1，2，奚家米1，张海燕1
(1.西安科技大学，陕西西安710054；2. 教育部西部矿井开采及灾害控制重点实验室，陕西西安710054)
摘 要:要进行大尺度采空区衍生动力学灾害的准确预测预报,必须进行煤岩破裂与演化为动力学失稳的定量化实验的前期研究。大柳塔煤矿1~2煤处于厚风积沙、浅埋深、薄基岩工程与地质环境中，要实现6m厚煤层一次全厚开采，采后形成大范围采空区上覆煤岩破裂并演化为动力学失稳,极易诱发衍生灾害。基于对1-2煤破裂失稳的声发射相关实验，综合分析煤岩破裂声发射总事件、能率与时间的之间的定量关系，包括加载上升阶段、初始破裂阶段、加速破裂阶段、破裂失稳后、能量下降阶段与回弹阶段,这有助于确定合理的失稳前兆判据,以期对开采过程中诱发动力灾害的危险源在线辨识及预警提供定量化预报。
关键词：声发射；煤岩破裂实验；动力学失稳；特征参数；综合分析
中图分类号:TD315*.1 文献标识码：A
Comprehensive characteristics analysis of crack propagation
and dyamical destabilizaition of coal-rock
based on acoustic emission experiment
LAI ·Xing-ping1,2 ,ZHANG Yong1,2 , XI Jia-mi1,ZHANG Hai-yan1
(1. Xi'an University of Science and Technology, Xi' an 710054 , China;
2. China Educational Ministry Key Lab. of Western Safe Mining & Hazard Control , Xi'an 710054 ,China)
Abstract :To accurately predict the dynamical hazard of a large scale mined-out area, the quantitative ex-periment on unstable crack propagation and dynamical destabilization on coal-rock have been fulfilled previously. The No. 1-2 coal locates thick. -sand on surfacef and shallow-depth and thin rock· -base engi-neering geological environment. Large scale mined-out area will be caused once to mine coal thoroughly (6m) at Da-Liu-Ta coal mine in Shanxi province. The overburden coal-rock will collapse and result indestabilizing effect so as to derive dynamic hazard easily. Based on the AE interrelated experiment on No.1-2 coal crack growth, the quantitative regularity of total-AE-event and time , energy-rate and timehas been comprehensive analyzed respectively. The process includes rising stage , initial crack stage, ac-celerating damage stage, after damaged and anti-elastic energy stage. These characteristic regularity willbe regarded as collapsing load foreboding evidence so as to on-line identify of mining derived dynamichazard and quantitative predict.
Key words : acoustic-emission( AE) ;experiment on unstable crack growth of coal-rock ; dynamical destabilization ;characteristic parameters ;comprehensive analysis
0 引 言
岩石受载后其内部微破裂萌生、扩展和断裂过程中会产生声发射现象(AE)。通过研究岩石破坏过程的声发射前兆特征、声发射参数与岩石破裂之间的关系，为进行大尺度采空区衍生动力学灾害准确预测预报提供依据。国内外学者曾开展过岩石破裂全过程声发射演化特征的研究[1-5]，但目前对西部矿山采空区煤岩破裂失稳的声发射特征研究还很少涉及，因此很有必要开展该方面的相关研究。大柳塔煤矿处于侏罗系煤田，1-2易燃煤层处于厚风积沙、浅埋深、薄基岩地质环境中，要实现大采高(6m)煤层安全高效开采，必须对开采后形成的大尺度采空区煤岩破裂及动力学失稳进行预测预报。通过对1-2煤样单轴受压破坏过程中声发射特征实验与参数统计，分析煤岩受力、变形直至破坏全过程中总事件--时间(T_AE-T)、能率--时间(N-T)之间的动态关系进行对比分析，从微观破裂孕育、产生、演化直至宏观失稳的全过程揭示1-2煤岩破裂过程与声发射特征参数之间的内在规律。
