堤坝下矸石充填采煤充实率设计

Design on backfill bodys compression ratio in waste backfilling coal mining under dam

为达到节约矸石充填量和确保堤坝安全的双重目的,需对矸石充填采煤充实率进行合理的设计,首先通过理论分析确定矸石充填采煤充实率的影响因子及各因子的影响情况;然后以济宁三号煤矿南阳湖堤下矸石充填采煤为实例,根据南阳湖堤的特点以及采煤规范确定设防标准,通过全部垮落法沉陷预计确定矸石充填量以及充填范围,由此动态确定该湖堤下矸石充填采煤充实率。结果表明:当工作面推进到距湖堤340 m时,采空区充实率需达到15.8%,随着工作面接近湖堤,采空区充实率应逐渐提高,当工作面推进到距湖堤60 m时,采空区充实率需达到91.8%;最后根据等价采高沉陷预计地表变形,该设计充实率不但能保护地表湖堤的安全,同时还节约了矸石充填材料。

The paper aimed to illustrate a rational design on backfill bodys compression ratio( BBCR) in waste backfilling coal mining,which could save the amount of waste backfilling and ensure the safety of dam. Firstly,the authors theoretically analyed on factors that influenced the value of BBCR and each factors actual effect of the BBCR. Secondly,a case studied on waste backfilling coal mining in Jining No. 3 Coal Mine under Nanyang Lake Dam to elaborate the BBCR dynamic design according to the dams feature and the coal mining specification to define the fortification standard and with the surface subsidence prediction using fully caving method to define the amount and range of waste backfilling,as instance,the BBCR should be at least 15. 8% when the mining face was 340 m away from the dam,and the BBCR levels up as mining face goes closer to the dam,the BBCR should reach 91. 8% as the mining face was 60 m away from the dam.Finally,a conclusion according to the surface subsidence prediction using equivalent mining height model that the rational BBCR design not only ensured the safety of the dam,but also saved filling materials and provides scientific basis for the layout of the project.