基于改进梁模型的地下空区顶板安全厚度分析

针对天然水平应力程度对地下采空区的影响,以某地下矿山采空区为工程实例,将地下空区顶板视为改进梁模型,结合岩梁、结构力学和材料力学理论,以顶板岩层抗拉强度为控制条件,推导出地下空区不同跨度下顶板的安全厚度。研究结果表明,顶板安全厚度随空区跨度的增加而增大,近乎呈线性关系。低水平应力时随空区跨度增加对顶板厚度整体影响都较小;当采空区跨度较小时,不同水平应力程度对顶板安全厚度的影响可忽略不计;当空区跨度达到一定程度时,随空区跨度的增加改进梁模型计算的顶板安全厚度增加幅度变大。

Analysis of roof safety thickness in the underground goafbased on improved beam model

According to the mined-out regions implications of natural horizontal stress level , an underground goaf is taken as an engineering instance. The roof of underground vacant area was regarded as an improved beam model , combined with rock beam theory, structural mechanics and material mechanics theory, the determination of the roof safety thickness in various goaf span was derived by taking the tensile strength of roof as the constrain condition. The results indicate that the height of roof increases with the increasing of goaf span and is approximately linear. The low horizontal stress has a little effect upon the thickness of roof with the increasing of the span. When the span of vacant area is small ,different horizontal stress degree has little impact on the thickness of roof. In a certain extent goaf span, the roof safety thickness of improved beam model increasing amplitude heighten with the increase of the span.