上提工作面支架围岩关系及其对矿压显现的影响

 针对淮南矿区提高回采上限工作面易于发生压架事故，采用理论分析和现场实测对上提工作面特殊的覆岩结构及其压架机制进行了研究。建立了不同覆岩结构围岩–支架力学模型，推导出了上覆基岩及松散层作用在关键层上的载荷，确定了支架临界工作阻力，并提出了相应的工作面压架防治措施。研究结果表明：以直接顶充填系数、覆岩关键层结构、基岩面表土层水文地质结构为判据，可将上提工作面覆岩结构分成4大类6种。单一关键层结构上提面压架危险性要比多层关键层结构高。对于单一关键层结构，当工作面临近松散承压含水层时，关键层距离含水层越近，水压越大，则作用在关键层上的载荷越大，关键层“砌体梁”结构越容易发生滑落失稳；当基岩面为厚黏土层时，采动影响下黏土层内部形成自然平衡拱结构，在“拱”结构保护下，“砌体梁”不易发生滑落失稳。

RELATION BETWEEN SUPPORT AND SURROUNDING ROCKS AND ITS INFLUENCE ON STRATA BEHAVIORS IN WORKING FACE WITH A RAISE OF MINING UPPER LIMIT

Aiming at the powered support jammed accidents are prone to take place in the working face with a raise of mining upper limit of Huainan mine area，the special overlying strata structure and its mechanism of powered support jammed are researched by using of theoretical analysis and field measurement. The corresponding mechanical models of support and surrounding-rock are established for different overlying strata structure，the loads of topsoil layer and overlying strata transfer into the key strata is deduced，the critical support working resistance is defined，and related preventive measures are put forward. The results show that: the structure type of overlying strata can be classified into six groups within four types according to filling coefficient of immediate roof，overburden key strata structure，and hydrogeology of topsoil layer on the bedrock surface. The risk of powered support jammed with single key strata structure is higher than that with multi-key strata in upper exploitation limitation-heightened working face. For the single key strata structure，when mining below the unconsolidated confined aquifer，the load on the key strata increases with the decrease of distance from the key strata to the aquifer and the increase of hydraulic pressure，so，the key stratum“voussoir beam”structure is more prone to sliding instability; while mining below the thick hardpan，the natural balance arch structure is formed in the hardpan，the sliding instability is not likely occur in the“voussoir beam”structure with the protection of arch structure.