厚层松软复合顶板煤巷梯次支护力学原理及应用

Mechanical principles and application of a multi-length support technology to a coal roadway with thick soft combined roof during deep mining

井厚层软弱复合顶板巷道围岩,单一长度的锚索加强支护,形不成稳固的承载结构,导致下位岩层离层,巷道围岩继续变形和破坏.提出了梯次支护原理,首先采用锚杆支护在巷道顶板浅部围岩造壳(一阶支护),再采用短锚索支护控制顶板中下部软弱煤岩形成二次强化锚固承载结构(二阶支护),再应用长锚索对已形成的二阶锚固承载体向顶板上部深层煤岩体实施整体组合锚固(三阶支护),在顶板岩层中形成一定厚度和承载强度的具有组合锚固效应的阶梯式立体支护结构,并对其支护力学原理进行了理论分析.该支护技术成功应用于淮南顾桥煤矿11151轨道顺槽,其巷道顶板浅部围岩离层分别为10和14 mm左右,深部围岩离层最大值为23 mm.

Stabilizing the load bearing structure of a roadway roof when it consists of a thick,soft layer can not be done with a set of equal-length anchors.This is because the roof will separate and deformation will destroy the structure.A multi-length support method is proposed.The lower roof is supported with bolts that form a shell.Then a second set of middle length anchors are installed into the roof that make a second load bearing structure.Thirdly,the long anchors are installed deeply into the roof that form a compositing bolted bearing structure.Thus,the thick soft layer of the roof is controlled by this multi-step,three dimensional support structure because of the load bearing strength and thickness it creates.A theoretical analysis of the support is presented.A successful application of the technology in the 11151 gateway of the Guqiao mine is described.The separation of the lower roof of roadway was about 10 and 14 millimeters,and the maximum separation in the deep roof was about 23 millimeters.