Safe roof thickness and span of stope under complex filling body
来源期刊：中南大学学报(英文版)2013年第12期
论文作者：Luo Zhou-quan(罗周全) XIE Cheng-yu(谢承煜) JIA Nan(贾楠) yang Biao(杨彪) CHENG Gui-hai(程贵海)
文章页码：3641 - 3647
Key words：complex filling body; roof thickness; span of goaf; mechanical analysis; numerical analysis
Abstract: Longhole caving method was used to mine gently inclined thick orebody step by step in a test stope of tin mine under complex filling body. The problem that the complex filling body around the stope affects the stability of roof thickness, chamber and spacer pillar in actual mining was investigated; meanwhile, the formed goaf during mining is so vulnerable that surrounding rock collapses early. Based on this point, elasticity mechanics and limit span theory were used to study separately the roof thickness and the span limit of goaf formed in mining, and then a reasonable roof thickness of 8 m and goaf span of 14 m are proposed. In addition, the stability of roof thickness, chamber and spacer pillar were investigated and analyzed by using numerical analysis method; meanwhile, the field monitoring on the displacement of caving chamber was conducted. The results show that the maximum compressive stress of surrounding rock is 20 MPa, and the maximum tensile stress is 1.2 MPa, which is less than the ultimate tensile strength of 2.4 MPa. Moreover, plastic zone has little influence on stope stability. In addition, the displacement of 11 mm is also smaller. The displacement monitoring results are consistent with the numerical results. Thus, the roof thickness and span of goaf proposed are safe.
Luo Zhou-quan(罗周全)1, XIE Cheng-yu(谢承煜)1, JIA Nan(贾楠)1, yang Biao(杨彪)1, CHENG Gui-hai(程贵海)2
(1. School of Resources and Safety Engineering, Central South University, Changsha 410083, China;
2. College of Resources and Metallurgy Engineering, Guangxi University, Nanning 530004, China)
Abstract:Longhole caving method was used to mine gently inclined thick orebody step by step in a test stope of tin mine under complex filling body. The problem that the complex filling body around the stope affects the stability of roof thickness, chamber and spacer pillar in actual mining was investigated; meanwhile, the formed goaf during mining is so vulnerable that surrounding rock collapses early. Based on this point, elasticity mechanics and limit span theory were used to study separately the roof thickness and the span limit of goaf formed in mining, and then a reasonable roof thickness of 8 m and goaf span of 14 m are proposed. In addition, the stability of roof thickness, chamber and spacer pillar were investigated and analyzed by using numerical analysis method; meanwhile, the field monitoring on the displacement of caving chamber was conducted. The results show that the maximum compressive stress of surrounding rock is 20 MPa, and the maximum tensile stress is 1.2 MPa, which is less than the ultimate tensile strength of 2.4 MPa. Moreover, plastic zone has little influence on stope stability. In addition, the displacement of 11 mm is also smaller. The displacement monitoring results are consistent with the numerical results. Thus, the roof thickness and span of goaf proposed are safe.
Key words:complex filling body; roof thickness; span of goaf; mechanical analysis; numerical analysis
