为了研究挠褶带内复合破碎型煤巷顶板的控制方法,对具有典型复合破碎顶板特征巷道掘进期间发生的数次小型和2次较大型冒顶事故进行现场观察和理论分析,总结了在挠褶带影响下巷道顶板围岩的5个典型特点,探讨了复合破碎煤巷顶板冒落的松脱型垮冒和挤压型垮冒2种垮冒类型.针对复合破碎煤巷顶板的2种垮冒类型,提出了采用将被动的前探梁临时支护改为单体柱主动支护或掘进机载临时支护梁和提高锚杆的初始预紧力,来控制松脱型垮冒;提出了采用增大锚固范围和采用基于巷道上帮角锚固的锚索桁架系统来控制渐次离层的方法来控制挤压型垮冒.分析了锚索桁架系统的支护原理,确定了锚索桁架的支护参数,现场应用结果表明:挠褶带内复合破碎型煤巷顶板主要发生松脱型和挤压型2类冒顶,其中松脱型垮冒通常只能减弱,不可避免,是挠褶构造生成时挤压、拉伸等造成破碎顶板围岩的固有特性;通过及时安装锚索桁架和锚杆网组合支护可以控制复合项板渐次离层,避免巷道发生挤压型垮冒.%In order to study the roof control method of the complex broken seam gateway within a flexure zone,a site observation and theoretical analysis were conducted on several small and two large roof falling accidents occurred in the gateway driving period with the typical broken roof features.The paper summarized the five typical features of the roof smrounding rock along the seam gateway under the influences of the flexure zone and discussed the two collapse falling types of the loose separation type collapse falling and the extrusion type collapse falling in the roof falling of the complex broken seam gateway.According to the roof two collapse falling type of the complex broken seam gateway,the paper proposed that the active support of the hydraulic single prop or the temporary support beam of the roadheader was applied to replace the passive temporary support of the forepoling beam to improve the initial pre-tension force of the bolt and to control the loose separation type collapse falling.The enlarged anchoring scope and the anchor truss system of the top corner anchoring in the gateway were applied to control the gradual bed separation and to control the extrusion type collapse falling.The paper analyzed the support principle of the anchor truss system and determined the support parameters of the anchor truss.The site application results showed that the roof of the complex broken type seam gateway within the flexure zone mainly would cause the loose separation type collapse falling and the extrusion type collapse falling.Among them,the loose separation collapse falling would only weaken generally and would not be avoided.The loose separation collapse falling would have the natural features of the broken roof surrounding rock caused by the extrusion,tension and others during the formation process of the flexure structure.The anchor truss and the bolt and steel mesh combined support timely installed could control the complex roof gradual separation and could avoid the extrusion type collapse falling.
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