摘要
以任家庄煤矿拟充填工作面为工程背景,通过相似材料模拟实验,统计分析了覆岩裂隙数量、角度、长度、宽度等参数,研究了充填开采覆岩裂隙的时空演化规律和分布特征。结果表明,煤层开挖充填距离较短时,近煤层的低位岩层首先产生横向裂隙,裂隙数量少、角度呈近水平。随着开挖充填距离的增加,横向裂隙的数量和长度均呈增加趋势。横向裂隙衍生出的非贯通性纵向裂隙基本分布在煤柱与采空区交界的区域内,其长度相对较短,角度普遍大于180°。覆岩裂隙由低位岩层逐渐向高位岩层发育扩展,裂隙分布范围逐渐扩大,在关键层处裂隙发育受到一定阻碍,采充区中部覆岩的裂隙发生缩小和闭合现象,减缓覆岩裂隙数量的增加;停采后的覆岩裂隙宽度普遍小于0.8mm,由裂隙两端向中部位置,裂隙宽度呈现先增大后减小的变化趋势;开采起始位置的覆岩裂隙宽度比停采位置附近的覆岩裂隙宽度要大。最后针对充填开采覆岩裂隙演化过程提出了有针对性的控制措施。研究结果对于深入认识导水裂隙发育演化和保水采煤具有重要意义。
Taking the proposed backfill face of Renjiazhuang Mine as the engineering background,through similar material simulation experiments,the parameters such as the number,angle,length and width of overburden fractures are statistically analyzed,and the temporal and spatial evolution law and distribution characteristics of overburden fractures in backfill mining are studied.The results show that the excavation and backfill distance of coal seam is short,and the low-level rock stratum near the coal seam first produces transverse fractures,with a small number and a nearly horizontal angle.With the increase of excavation and backfill distance,the number and length of transverse fractures increase.The non penetrating longitudinal fractures derived from transverse fractures basically distribute at the junction area of coal pillar and goaf.Their length is relatively short and the angle is generally greater than 180°.The overburden fractures gradually develop and expand from lowlevel rock stratum to high-level rock stratum,and the fracture distribution range gradually expands.The fracture development at the key stratum is hindered to a certain extent.The fractures in the overburden in the middle of the mining and backfill area shrink and close,slowing down the increase in the number of overburden fractures.The fracture width of overburden after stopping mining is generally less than 0.8mm.From both ends of the fracture to the middle,the fracture width first increases and then decreases;the width of overlying rock fracture at the mining starting position is larger than that near the stopping position.Finally,targeted control measures are put forward for the evolution process of overburden fractures in backfill mining.The research results are of great significance for further understanding the development and evolution of water conducting fractures and water retaining mining.
作者
徐连兵
杨科
赵新元
XU Lian-bing;YANG Ke;ZHAO Xin-yuan(China Energy Investment Group Co.Ltd.,Beijing 100010,China;Anhui University of Science and Technology,Huainan 232001,China)
出处
《煤炭工程》
北大核心
2022年第7期86-91,共6页
Coal Engineering
基金
国家重点研发计划资助项目(2019YFC1904304)
合肥综合性国家科学中心能源研究院科研项目(21KZS217)。
关键词
充填开采
覆岩裂隙
时空演化
相似模拟
backfill mining
overburden fractures
temporal and spatial evolution
similar material simulation
