Structure Forms of Basic Roof and Reasonable Supporting Parameters in Ends of Fully- Mechanized Top Caving Face

摘要：  端头液压支架支护强度的确定是支架设计与选型的关键，为此，理论分析了端头区覆岩垮落形态、基本顶的结构运动规律及合理支护强度的确定方法。研究表明：端头区基本顶既可为裂隙带岩层，也可为垮落带岩层，裂隙带基本顶弧形三角块的下沉运动与工作面中部砌体梁相同，垮落带基本顶弧形三角块形可为仅受煤壁支撑与覆岩压力的悬臂梁，或同时与前后弧形三角块铰接形成弧形三角块类砌体梁结构；基本顶弧形三角板不同的结构形式，矿压显现不同，砌体梁结构基本顶活动的压力显现明显，动载系数大，而弧形三角块类砌体梁基本顶活动的压力显现不明显，动载系数较小；端头区支架与围岩作用关系中，支架的工作状态有3种类型：给定变形状态、限定变形状态和给定载荷状态，可根据对应的端头区砌体梁模型、悬臂梁模型和弧形三角块类砌体梁模型估算不同条件下端头支架合理的支护强度．

关键词: 端头支架；弧形三角块；支护阻力

Abstract:  The determination of face-end hydraulic support resistance is the key to support design and selection．Therefore，theoretical analyses were carried out in this paper to study the collapse of overburden，movenment rules of basic roof structure，and determination method of resonable supporting parameters in the face-end area．The results show that the basic roof can be the fractured or caving rock stratum in the face-end area．The sinking motion of the arc triangular pieces in the fractured zone is the same with the voussoir beam in the middle of the face，while the arc triangular pieces in the caving zone can be regarded as the cantilever beam which is only supported by coal wall and loaded by overburden pressure，or forms the similar voussoir beam structure hinged with the frontal and posterior arc triangular plates mutually．Different triangular plate structures of main roof result in different pressure behavior，that is，the pressure behavior of main roof is obvious in the voussoir beam structure，and the dynamic load coefficient is large，while the similar voussoir beam hinged by triangular plate structures results in less pressure behavior and smaller dynamic load coefficient．In the action relation between the support and surrounding rock in the face-end，the working conditions of support include three types：given deformation state，limited deformation state，and given loading state．Meanwhile，the reasonable supporting strength of face-end support under different conditons can be estimated by the corresponding voussoir beam，cantilever beam，and the similar voussoir beam hinged by triangular plate structures in the face-end area，respectively．

Key words: face-end hydraulic support；arc triangular plate；support resistance