综放面动压回采巷道帮部大变形控制机理及应用
Control mechanism and application of large deformation of dynamic pressure roadway of fully mechanized top-coal caving face
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摘要: 基于综放面动压回采巷道的变形特征和两类滑移面的分布规律,研究了锚杆,锚索与第Ⅰ类及锚索与第Ⅱ类滑移面的微结构的力学模型,得到了一级和二级锚固体的重构机理,提出了"携顶底,控两帮"的支护思想,并推演了该思想的演化图解;运用FLAC3D数值模拟研究了综放面回采巷道在3种不同支护方案下的变形破坏规律,研究结果表明,与方案一相比,采用方案二和方案三支护的巷道破坏深度和塑性区发育单元体数量分别减小了44.4%,66.7%,巷道掘进与回采期间帮部变形分别减少了51.4%和68.6%,50%和68.9%;将新的支护思想在综放工作面回采巷道沿底和沿顶掘进两种情况下进行了工业性试验,结果表明,新思路下巷道围岩变形得到了有效控制;研究结果对类似工程地质条件下综放回采巷道的围岩控制具有重要的指导意义.Abstract: Based on the distribution law of two types of slip surface and the deformation characteristics of dynamic pressure roadway in fully mechanized top-coal caving face, the mechanical model for microstructure of anchor bolts, Class I slip surface and Class II slip surface are studied. The reconstruction mechanisms of level-one and level-two anchors are obtained. The support idea of "top and bottom to help control the sides" is put forward, and the evolution of the graphic is deduced. The roadway deformations and failure laws under three different support programs of fully mechanized top-coal caving face are studied through numerical simulation of FLAC3D. The results show that compared with option I, roadway damage depth and plastic zone development unit based on option II and III are reduced by 44.4% and 66.7%, and the deformations of two sides are reduced by 51.4% and 68.6%, and 50% and 68.9% during roadway excavation and mining. The industrial tests on mining roadway along the bottom and the top of tunneling by the new support idea are developed on the fully mechanized top-coal caving face. The roadway deformation by the proposed method can be effectively controlled, and meets the requirements of production safety. The results have important guidance to the surrounding rock control of caving mining roadway under similar engineering geological conditions.