软岩矿山采场结构参数优化

Optimization of structure parameters for stope in a soft rock mine

软岩矿山采用矿房法回采时,其顶板往往存在较多节理和裂隙,已不适合用连续梁理论来分析,项目组应用伏萨尔梁法计算梁上最大抗压应力,并对某石膏矿山不同采场结构参数顶板稳定安全系数进行了评估计算,运用Flac-3D模拟不同条件下采场最大主应力及位移分布情况。研究结果:矿房跨度增加,顶板的最大拉应力成正相关,顶板沉降量也成正相关;顶板厚度的增加,使得顶板的拉应力峰值呈上升趋势,而顶板沉降位移呈减小趋势;最终确定采场结构参数为:矿房顶板厚度0.75m,跨度10m。

The roof tends to have more joints and fissures when stoping operation takes place in a soft rock mine. It is not suitable for the continuous beam theory to analyze these problems. The maximum compressive stress for the beam was calculated by Voussoir Beam method and the roof stability and safety factors for the different structures in a gyRsum mine were evaluated and calculated. The maximum principal stress and displacement dis- tribution for the stope under the different conditions. The results showed that with the larger stope span, it is positively ＂correlated to the maximum tensile stress and the roof subsidence as well. The greater thickness of roof results in its peak value of tensile stress on the increase and its subsidence displacement on the de- crease. The final stope structure parameters are determined as 0. 75 m in thickness and 10 m in span for the stope roof.