基于Ⅰ-Ⅱ复合型裂纹破坏模式的条带矿柱破坏宽度研究  

Analysis for the breadth of the pillardamaged mining strip based onⅠ-Ⅱ mixed crack mode

作　　者：施耀斌[1,2] 叶义成[1,2] 刘艳章[1,2] 王其虎[1,2] 岳哲[1,2] 夏张琦 

机构地区：[1]武汉科技大学湖北省页岩钒资源高效清洁利用工程技术研究中心,武汉430081 [2]武汉科技大学资源与环境工程学院,武汉430081

出　　处：《安全与环境学报》2017年第3期888-895,共8页Journal of Safety and Environment

基　　金：国家"十二五"科技支撑计划项目(2011BAB05B03);国家自然科学基金项目(51074115);湖北省科技支撑计划项目(2014BCB033)

摘　　要：采用条带法进行地下开采时,条带矿柱的裂纹扩展导致了矿柱的最终破坏,且裂纹多表现为Ⅰ型裂纹与Ⅱ型裂纹复合扩展破坏特征。根据采场矿柱受力条件,确定条带矿柱受两侧采场空区影响时矿柱内Ⅰ-П复合型裂纹尖端的Westergaard应力函数,采用HoekBrown强度准则计算采场作业面围岩破坏区的边界条件,建立了矿柱破坏宽度计算模型。以上横山页岩矿床为研究对象,采用物理相似模拟试验,模拟条带法回采某盘区3个试验区段,利用DIP法分析受地应力及回采扰动作用下矿柱的裂纹发育特征,验证模型的有效性。结果表明,条带及其条带矿柱均为15 m等设计参数条件下,计算模型矿柱破坏宽度理论值分别为17.66 m、15.56 m和10.28 m,试验模拟结果分别为完全大于15 m、约为15 m和10.5~11.0 m,试验结果与依据模型计算的理论值相近。In this paper,we would like to determine the Westergaard stress function of the cracked tip on the pillar with its both sides being extracted,in reliance on the analysis of the pillar stress characteristic features in the strip mining and the Ⅰ-Ⅱmixed mode fracture criteria. As is known,under the condition of the underground strip mining,the rock-cracking propagation may lead to the ultimate collapse of the strip-pillars,which tends to take a destructive crack feature usually as Ⅰ-Ⅱ mixed mode crack-expansion. To further clarify and work out the boundary conditions of the failure region around the rock-layers according to Hock-Brown strength criteria,we have constructed a likely-to-be destructible width model of the pillar. And,furthermore,we have taken the Shanghengshan shale deposits as the research sample so as to verify the validity of the model,based on the pillar that might have been impacted by the underground stress and the mining disturbance through a series of simulated experiments in the third test section along with an analysis of the cracks likely-evolutionary or developmental features of the pillar. And,finally,we have adopted the digital image processing to verify the validity and effectiveness of the said model. Thus,the results of our comprehensive experiments for testing the physical similarity simulation and analytical tests demonstrate that,the predictive values of the pillar damaged width as expected proves to be respectively greater than 15 m,about 15 m and 10. 5-11. 0 m. What is more,the said predicted values turn to be well matched with the theoretical values known as 17. 66 m,15. 56 m and 10. 28 m,correspondingly under the conditions of the aforementioned 3 research objects,that is,the strip and strip pillar design width should be15 m. Therefore,it can be concluded that the values of the pillar damaged width analysis we have worked out prove to be close to the testing data of the above mentioned similar simulation experiments. Thus,the validity of the model proves to be well in ag

关 键 词：安全工程 条带法 矿柱 破坏宽度 Ⅰ-Ⅱ复合型裂纹 HOEK-BROWN强度准则 DIP 

分 类 号：X936[环境科学与工程—安全科学]