深部低品位资源阶段空场嗣后充填采矿法采场结构优化与稳定性控制

Stope structure optimization and stability control of stage open stopingand subsequent filling mining method for deep low-grade resources

基于阶段空场嗣后充填采矿法采场围岩稳定性控制难题,以某矿山深部急倾斜厚大矿体的赋存条件为背景,从改变采场几何形态和结构参数角度出发,提出将阶段采场顶部改变为拱形结构,开展拱形结构阶段空场嗣后充填采矿法围岩稳定性研究。从采场拱形形态及阶段采场跨高比入手,分析2个因素对采场稳定性影响。研究结果表明:采场拱形形态的设置和跨高比的优化可以提升采场整体稳定性。通过建立阶段采场拱形结构力学承载模型,进行采场拱形形态及跨高比因素的影响权重分析。跨高比对采场综合稳定性的影响最大,影响权重为66.41%,采场拱形形态对采场的边墙稳定性影响显著,影响权重为94.83%。综合围岩位移、裂纹演化规律及围岩开裂区等效深度等指标计算结果,确定最优采场结构参数为:采场高50 m、跨度20 m、采场形态特征角55°。

In response to the challenge of controlling the stability of the surrounding rock of stope with stage open stoping and subsequent filling mining method,taking the occurrence conditions of the deep steep-inclined thick ore body in a mine as the background,and from the perspective of changing the geometric shape and structural parameters of stope,it is proposed to change the top of stage stope into an arch structure,and carry out the research on the stability of surrounding rock with arch structure stage open stoping and subsequent filling mining method.Based on the arch shape of the stope and the span-height ratio of the stope in different stages,the influence of the 2 factors on stope stability is analyzed.The research results show that the setting of the arch shape and the optimization of the span-height ratio can improve the overall stability of the stope.By establishing the mechanical bearing model of the stage stope arch structure,the influence weight of arch shape and span-height ratio factors is analyzed.The span-height ratio has the greatest influence on the comprehensive stability of the stope,with an influence weight of 66.41%,and the arch shape of the stope has a significant influence on the stability of the stope side wall,with an influence weight of 94.83%.Based on the calculation results of surrounding rock displacement,crack evolution law,and equivalent depth of surrounding rock cracking zone,the optimal stope structure parameters are determined as follows:the height of stope is 50 m,the span is 20 m,and the stope mophorlogy characteristic angle is 55°.