煤巷强帮支护理论与应用

THEORY AND APPLICATION OF STRONG SUPPORT FOR COAL ROADWAY SIDEWALL

在分析煤巷帮部破坏机制和加固机制的基础上,通过建立煤巷力学模型、分析支护力与莫尔圆的关系、研究帮部极限平衡区宽度及巷道耗能机制,提出强帮护顶概念设计,从理论方面对煤巷强帮支护理论进行论证。应用FLAC3D软件对煤巷进行模拟,详细分析巷道开挖引起的围岩力学响应情况,阐明帮锚杆对帮部强度的影响,从数值模拟角度对煤巷强帮支护理论进行论证。最后,煤巷强帮支护理论被成功应用于马兰、官地等矿山煤巷支护设计,在实践中取得良好效果。研究结果表明:(1)提高煤巷帮部支护强度,一方面可提高帮部对顶板的承载力,另一方面会减小帮部极限平衡区宽度和顶板广义跨度。(2)提高煤巷帮部结构体与顶板结构体的强度比值和刚度比值,有利于减少帮部结构体塑性铰的数量,使巷道结构体形成合理耗能机制,提高整体稳定性。(3)针对帮部比顶板岩体强度低的巷道,采用强帮护顶概念设计形成强帮护顶良性作用机制与合理耗能机制,以保证巷道的安全性。(4)增加煤巷帮锚杆直径、长度或增大帮锚杆布置密度,可达到有效控制围岩变形、减少极限平衡区的效果。(5)数值模拟与现场应用均表明,提高煤巷帮部的强度可以提高巷道的整体稳定性,煤巷强帮支护理论在工程实践中具有良好的适用性。

On the basis of analyzing destructive mechanism and reinforcement mechanism of coal roadway sidewall, concept design of protecting the roof by strong sidewall is put forward by means of establishing mechanical model of coal roadway, analyzing relationship between supporting force and Mohr circle, researching the width of limit equilibrium zone in sidewall and mechanism of roadway energy dissipation~ and the theory of strong support for coal roadway sidewall is also theoretically demonstrated. FLAC3D is used to analyze surrounding rock＇s mechanical response caused by coal roadway excavation and clarify influences of sidewall bolt on sidewall strength. So the theory of strong support for coal roadway sidewall is demonstrated through numerical simulation. Finally, theory of strong support for coal roadway sidewall is applied to coal roadway supporting design of Malan and Guandi mines. Good results have been obtained in these practices. The study results show as follows： （1） Improving the support strength of sidewall can not only enhance the bearing capacity of sidewall on the roof, but also reduce the width of limit equilibrium zone in sidewall as well as generalized span of roof. （2） Increasing strength ratio and stiffness ratio between the sidewall and roof can decrease quantity of plastic hinges insidewall, which makes reasonable mechanism of roadway energy dissipation, ensuring the overall stability of coal roadway. （3） Using the concept design of protecting the roof by strong sidewall to support roadway which has lower strength in sidewall than roof can form the well function mechanism of protecting roof by strong sidewall, as well as the reasonable mechanism of roadway energy dissipation, which ensure the safety of coal roadway. （4） Increasing diameter, length, density of sidewall bolt can effectively control the deformation of surrounding rock and decrease limit equilibrium zone. （5） Both numerical simulation and field application indicate that improving the strength of sidewall can improve the overall stability. good applicability in engineering practice. Theory of strong support for coal roadway sidewall has