深部煤矿巷道等强梁支护理论模型及模拟研究

分析了矩形巷道顶板的受力特点，得到了顶板各位置弯曲正应力与剪力的分布规律。据此推导出了保证巷道顶板维持稳定所需的锚杆参数，并进一步对影响锚杆长度选取的各因素进行了敏感性分析，确定了各因素对锚杆长度选取影响程度的主次关系。由此得出了不同长度锚杆支护下的巷道围岩能够满足稳定性要求，基于此提出了深部巷道等强梁支护概念，即根据顶板弯曲正应力分布特征，在中部弯曲正应力大的区域，采用高强度、长锚杆局部加强;而在两边弯曲正应力逐渐减少的区域，可适当减少锚杆的长度，但增加锚杆直径提高抗剪能力，以期实现巷道顶板各横截面上在不同长度锚杆支护作用下最大正应力都相等，初步建立了等强梁支护施工技术工艺。运用有限差分软件FLAC3D模拟获得了锚杆原有传统支护与等强梁支护下顶板应力及位移分布规律，可看出采用等强梁支护理念可明显优化巷道的应力分布，让顶板局部应力达到均匀分布，并且有效控制了围岩变形，在一定程度上验证了等强梁支护技术的可行性。

Theoretical model and simulation study of uniform strength beam support in deep coal mine roadway

In this paper,the stress characteristics of the rectangle roadway roof is analyzed.The distribution law of the bending normal stress and shear force of the roof is obtained.The bolt parameters to ensure the stability of the roadway roof are deduced.Furthermore,the sensitivity analysis of the factors influencing the length selection of bolt is carried out.The primary and secondary relations of each factor to the influence degree of bolt length selection are determined.Thus,the roadway surrounding rock with different lengths of bolt support can meet the stability requirement.The uniform strength beam support concept of deep roadway is put forward according to the bending normal stress distribution characteristic of the roof.High strength long bolt is adopted locally in the region with large bending normal stress.The length of bolt can be appropriately decreased in the area where the bending normal stress is gradually reduced.The same maximum normal stress can be achieved under different lengths of bolt support in the roadway roof.The construction technology of uniform strength beam support is preliminarily established.Finite difference software FLAC3D is applied to simulate the roof stress and displacement distribution of traditional bolt support and uniform strength beam support,respectively.Numerical results indicate that the uniform strength beam support can significantly optimize the stress distribution of roadway.And the local stress of roof reaches to the uniform distribution.The surrounding rock deformation also decreases.The results indicate that the uniform strength beam support technology is feasible for deep mining.