双矿柱体系变形破坏及承载特性的试验研究  

Experimental study on failure mechanism and bearing characteristic of double-pillar system

作　　者：周子龙[1] 陈璐[1] 赵源[1] 董陇军[1] 杜雪明[1] 蔡鑫[1] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083

出　　处：《岩石力学与工程学报》2017年第2期420-428,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家基础研究发展计划(973)项目(2015CB060200);国家自然科学基金资助项目(51322403);湖南省科技计划项目(2016SK2003)~~

摘　　要：为揭示外部载荷作用下矿柱体系的力学响应特性,开展单矿柱及双矿柱试样组的压缩试验,监测并分析矿柱变形破坏过程中的荷载、变形及声发射信息。研究表明:单矿柱压缩过程中,随着裂纹演化,其承载能力逐渐弱化,当其不足以承担外部荷载时,试验机储存的弹性能将迅速释放并导致矿柱突然破坏;相同力学性能矿柱组压缩过程中,两矿柱基本能均匀承载,协调变形且几乎同时丧失承载能力;不同力学性能矿柱组压缩过程中,低强度矿柱先出现裂纹,承载能力缓慢下降,与此同时荷载向高强度矿柱转移,当高强度矿柱出现宏观滑移时,双矿柱试样组整体随之丧失承载能力;单个矿柱的承载能力、应力状态及外部荷载与能量环境均对双矿柱体系的整体稳定有着显著的影响;进行地下矿床开采时,在设计常规矿柱基础上预留高承载能力边界矿柱,将能有效预防矿柱群大规模突发性失稳灾害。In order to understand the failure and bearing characteristics of pillars,the compressive tests on the single pillar and double-pillar specimens were conducted. The deformation, load and acoustic emission information of pillars were recorded and analyzed. It was found that when a single pillar was compressed,its bearing capacity decreased gradually with the propagation of micro-cracks. When it was not strong enough to bear the external load,the elastic energy stored in the test machine would release rapidly and caused the pillar to fail abruptly. In the compression process of the double-pillar specimen with two pillars having the same mechanical property,two pillars bore almost the same load and deformed simultaneously. In the compression process of the double-pillar specimen with two pillars having different mechanical properties,the pillar with the lower strength degraded earlier and lost the bearing capacity firstly. The load was then transferred to the other pillar. The system lost the bearing capacity when the macro-slip appeared in the pillar with the higher strength. For the multi-pillar systems,the strength of individual pillar,the inner stress state and the external load circumstance all have the influence on the final stability. In the underground mining practice,in order to prevent the massive pillar collapseeffectively,it is wise and necessary to leave the barrier pillars among the normal pillars.

关 键 词：采矿工程 双矿柱体系 数字散斑 极限承载 应力转移 裂纹扩展 

分 类 号：TD32[矿业工程—矿井建设]