基于能量理论的深埋矿山矿柱尺寸设计方法

Pillar Size Design Method for Deep Mine Based on Energy Theory

随着资源开发步入深部开采阶段,深埋矿山开采过程中的动力灾害问题日益突出,传统静力稳定分析方法在应对这些问题时表现出一定的局限性,研究适用于深部矿山的矿柱尺寸设计方法意义重大。本文基于面积承载理论和金属矿山矿柱强度估算方法,以一种动态的视角,从功能转换角度探讨了瞬间回采方式下的矿柱应变能积聚和转化特征,对地下矿体阶段性分层回采这一过程进行简化,提出一种基于可释放能理论的适应不同分层钻爆开挖方式下的矿柱尺寸参数设计方法;依托某工程实例,应用能量法,并与传统强度理论方法进行比较分析,据此建议5组矿柱尺寸参数方案;利用有限差分软件(FLAC3D)对此5种参数方案优化,最终确定了合理的矿柱尺寸设计值。结果表明:矿柱体受动态开挖作用将产生动力响应,诱发产生的动应力和动态变形可达静力分析时的两倍,同时伴随大量能量的积聚;与传统强度计算理论相比,应用能量法可有效地避免快速回采情况下矿柱动力失稳的可能,设计得到的矿柱尺寸参数更偏保守,随着开挖分层数的增多,能量法逐渐趋于和强度静力法等价。经数值模拟优化比选,最终建议该工程矿体分3层回采,矿柱合理宽度为22 m,高度为70 m,基本上可以满足回采过程中安全稳定和经济效益的需求,与工程实际契合较好。

With the development of resources entering the stage of deep mining,the problem of dynamic disasters in the mining process of deep buried mines has become increasingly prominent.When dealing with these problems,the limitations of traditional static stability analysis methods are shown,and it is of great significance to study the design method of pillar size suitable for deep mines.Based on the area bearing theory and the method of estimating pillar strength in metal mines,the characteristics of the pillar strain energy accumulation and transformation under the instantaneous mining method were mainly discussed through the dynamic functional transformation relationship.The process of staged stratified mining of underground ore bodies was simplified,and a design method of pillar size parameters based on the theory of releasable energy was proposed to adapt to different stratified drilling and blasting methods.Relying on an engineering example,the energy method was applied and compared with the traditional strength theory method.Then,five groups of pillar size parameter schemes were proposed,which were further optimized by finite difference software(FLAC3D)to finally determined the reasonable pillar size design value.The research results show that a certain degree of dynamic response occurs inside the mine pillar under the action of dynamic excavation,while the dynamic stress and dynamic deformation that can be twice as high as that of the static analysis were also generated,and a large amount of energy was accumulated at the same time.Compared with the traditional strength calculation theory,by applying the energy method,the possibility of dynamic instability of the pillar in the case of rapid mining can be effectively avoided,and more conservative pillar size parameters were designed.As the number of excavation layers increases,the energy check method gradually tends to be equivalent to the strength static method.After optimization and comparison through numerical simulation,a plan of mining in three times,the width of the mining pillar is 22 m,and the height of 70 m was proposed,which can basically meet the needs of safety,stability and economic benefits during the mining process,and it is in good agreement with the actual engineering.