多因素组合影响阶段矿柱上采顶板临界厚度研究  

Study of critical thickness of roof of level pillar stoping under multifactor influence

作　　者：王晓军[1,2] 冯萧[3] 赵奎[3] 邵海[1] 叶自欢 

机构地区：[1]江西理工大学资源与环境工程学院,江西赣州341000 [2]中南大学西部矿业博士后科研工作站,西宁810006 [3]江西理工大学工程研究院,江西赣州341000

出　　处：《岩土力学》2013年第12期3505-3512,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51364011);国家自然科学基金(No.51304083);江西省教育厅青年科学基金(No.GJJ12361)

摘　　要：采用散体充填法的矿山,由于充填体无法直接暴露,阶段矿柱回采临界厚度的保留成为残矿回收的突出难题。基于传统弹性梁理论,结合实际情况,将阶段矿柱简化为均布载荷下两端固定的弹性梁力学模型,推导了其弹性应力解,揭示了x?是阶段矿柱上采过程的第1破坏应力。理论分析表明:影响矿柱上采顶板临界厚度的主要因素为:散体载荷、回采跨度和岩体抗拉强度。利用FLAC3D完成了多因素组合影响阶段矿柱上采过程数值模拟正交试验,分析了单一影响因素与顶板临界厚度的关系,利用多元非线性回归的数学方法,建立了上采过程三因素组合影响下阶段矿柱临界厚度数学预测公式。最终,实现了散体介质下阶段矿柱上采临界厚度的预测。结合凤凰山铜矿-240 m阶段矿柱回采实际,表明了该预测公式的适用性。For level pillar stoping under loose medium, determining the critical thickness of roof is difficult. In order to solve the problem, using elastic beam theory, the level pillar is simplified as a mechanical model of a beam fixed at both ends under uniform load; and trx is considered to be the main failure stress according to the elastic stress solution of beam. Theoretical analysis shows： in level pillar stoping process, the main influence factors of critical thickness of roof is loose medium load, stoping span and tensile strength of rocks. Through using FLAC3~ and combining with orthogonal experiment result of numerical simulation, the relationship between single influence factor and critical thickness of roof is revealed. Based on multiple nonlinear regression analysis method, the mathematical forecasting formula of critical thickness of roof under multifactor influence is established. Finally, The critical thickness of the roof is predicted accurately; and applicability of the mathematical forecasting formula is verified by the engineering practice of level pillar stoping in Fenghuangshan Mine.

关 键 词：散体介质 临界厚度 弹性梁 正交试验 多元非线性回归 

分 类 号：TU42[建筑科学—岩土工程]