高应力硬岩卸荷岩爆的劈裂判据及因素敏感性分析  

Splitting criterion of unloading rock burst for high-stress hard rock and its sensitivity analysis of factors

作　　者：张晓君[1] 

机构地区：[1]山东理工大学资源与环境工程学院,山东淄博255049

出　　处：《采矿与安全工程学报》2013年第1期80-85,共6页Journal of Mining & Safety Engineering

基　　金：山东省自然科学基金项目(Y2008F51);山东理工大学青年教师发展支持计划经费项目;山东理工大学博士基金项目(4041410012)

摘　　要：针对现有岩爆研究的不足,基于突变理论建立了围岩卸荷岩爆的劈裂突变模型,得到了考虑卸荷影响的劈裂岩爆必要条件和充分条件并在此基础上进行了因素敏感性分析。研究表明,开挖卸荷致拉明显降低了突变特征值及岩爆发生的门槛,使岩爆发生的可能性大为增加,而且当拉应力σx=πσt/4时,必要条件就成为充分条件;卸荷后一段时间围岩发生变形,达到发生岩爆至少所需的卸荷细观拉应力,形成标准或滞后岩爆模式;竖向应力达到一定值,围岩卸荷瞬间其突变特征值Δ≤0,形成瞬时岩爆模式;岩爆劈裂要满足一定的临空面尺寸要求,随竖向应力的增大这种要求明显减弱;发生岩爆时岩爆区释放的能量ΔE,σx,Δ对竖向应力的敏感性很强,Δ对σ3极为敏感。In this paper, aiming at the existing defects of rock burst study, a splitting catastrophe model of unloading rock burst of surrounding rock was established based on the mutation theory, and the nec- essary and sufficient conditions of splitting rock burst were obtained while considering the unloading influence, then the sensitivity of influence factors was further analyzed. The results show that the muta- tion characteristic value and critical condition of rock burst were reduced obviously by excavation unloading, and the occurrence possibility of rock burst increases greatly, when the tensile stress meets the condition of σx=πσt/4, the necessary conditions will become the sufficient conditions. Meanwhile, the surrounding rock will be displaced after a period of unloading, the standard or delayed rock burst will occur when the unloading microscopic tensile stress reaches the needed condition to induce rock burst, while the instant rock burst occur will occur when the vertical stress reaches to a certain value and the mutation characteristic value of surrounding rock during unloading moment meets the condition of △≤0. In addition, the splitting of rock burst should satisfy a certain size requirement of free surface, and the requirement can be reduced significantly with the increasing of vertical stress. Moreover, thevertical stress have important influence on the AE, σx and △, while the horizontal stress have more im- portant influence on the △.

关 键 词：硬岩 卸荷岩爆 劈裂判据 突变 敏感性 

分 类 号：TD324[矿业工程—矿井建设]