Mohr-Coulomb准则下倾斜矿柱稳定性的安全系数法  

Safety factor method for stability of inclined pillars under Mohr-Coulomb criterion

作　　者：罗斌玉 叶义成[1,2] 李玉飞[1,2] 罗甲渊 陈虎 LUO Binyu;YE Yicheng;LI Yufei;LUO Jiayuan;CHEN Hu(College of Resources and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resource,Wuhan 430081,China;Liupanshui Administration of Work Safety of Guizhou Province,Liupanshui 553001,China)

机构地区：[1]武汉科技大学资源与环境工程学院,湖北武汉430081 [2]冶金矿产资源高效利用与造块湖北省重点实验室,湖北武汉430081 [3]贵州省六盘水市安监局,贵州六盘水553001

出　　处：《煤炭学报》2018年第9期2408-2415,共8页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51574183)

摘　　要：地下矿床开采中,矿柱的稳定是矿床安全高效开采的基础,是采场作业人员的安全保障。以弹性力学理论为基础,分析正应力和剪应力共同作用下倾斜矿柱的受力状态,应用图解法绘制出表征矿柱应力状态的应力圆。根据应力圆与Mohr-Coulomb强度包络线之间的关系,建立了考虑矿体倾角及矿柱受正、剪应力共同作用下矿柱的安全系数解析式。应用该安全系数解析式能很好评价任意倾角矿柱的稳定性,并分析了水平矿体时,以安全系数评价的矿柱稳定性与实际矿柱稳定状态吻合。最后分析了应力圆圆心所在直线斜率tanβ、矿体倾角θ等因素对倾斜矿柱稳定性的影响。研究表明:应力圆圆心所在直线斜率tanβ是矿体倾角θ及侧压系数λ的二元函数,对每个侧压系数λ,tanβ均能取得一次最大值,且侧压系数λ值不同,tanβ取得最大值亦不同;当侧压系数λ∈[0,1]时,tanβ取得最大值时对应的矿体倾角θ∈[45°,90°];当tanβ取得最大值时,矿柱的安全系数最小,矿柱最容易失稳;随矿体倾角的增大,矿体安全系数呈现先减小后增大的变化趋势。Stability of pillars is the basis of safety and efficient mining in underground mines,and it is the safety guarantee for operators.Based on the theory of elastic mechanics,the stress state of inclined pillars was analyzed under the combined action of normal stress and shear stress,and a stress circle was plotted by graphic method which describes the distribution of stress state of pillars.According to the relationship between stress circle and Mohr-Coulomb strength envelope,an analytical formula for the safety factor of pillars was established.Some factors had been taken into consideration in the formula,such as the dip angle of ore body,the average normal stress and shear stress of pillars etc.The analytic formula of safety factor can be used to evaluate the stability of the pillars under any angle ore body.In the flat seam case,the stability of the pillars was evaluated by the safety factor.Results show that it is in good agreement with the measured values.Finally,the pillars stability influence factors were studied,including the deposit dip angleθwith the slope of the stress circle(tanβ).Research shows that tanβis a binary function of the deposit dip angleθand the lateral pressure coefficientλ.Tanβcan achieve only one maximum value under any lateral pressure coefficient value,but lateral pressure coefficient is different,getting the most value is also different.When the lateral pressure coefficient is from 0 to 1,the corresponding range ofθis from 45°to 90°.When the maximum value of tanβis obtained,the safety factor is the smallest,and the pillar is most likely to be unstable.With the dip angle of ore body increasing,the safety factor decreases at first and then increases.

关 键 词：MOHR-COULOMB准则 倾斜矿柱 稳定性 安全系数 

分 类 号：TD82[矿业工程—煤矿开采] TD31[矿业工程—矿山开采]