摘要
为研究冒落矸石在切顶卸压沿空留巷过程中的力学作用,通过现场实测和理论分析对矸石的碎胀规律及其力学特性进行了研究。针对不同赋存条件总结归纳了4种冒落矸石碎胀系数的现场实测方法:可视分层直接测量法、整层划定界限法、坚硬顶板间接测量法和围岩变形反推计算法。建立了矸石碎胀规律与围岩运动的关系,实测表明矸石块度对初始碎胀系数影响大,但残余碎胀系数基本稳定在1.26,故复合顶板留巷后下沉量大,且矸石压实稳定时间随埋深加大而延长。构建了垮落矸石稳定后受力模型,并对挡矸支护所受侧向应力和矸石对顶板的支撑力进行了分析计算,证明矸石碎胀规律对于巷道顶板保持稳定具有重要作用。
In order to study the mechanical effect of fallen gangue in the goaf during the gob - side entry retaining formed by roof cutting and pressure releasing, the bulking rule and mechanical characteristics of the fallen gangue were studied by field measurements and theoretical analysis. According to different roof conditions, 4 kinds of field ~＇~easurement methods for bulk factor were summarized, including visual hierarchy direct measurement method, whole layer delimiting limit method, indirect measurement method of hard roof and calculation method by surrounding rock deformation. The relationship between mechanical characteristics of the fallen gangue and the surrounding rock movement was established, and the actual measurements indicated that the size of waste rock had a great influence on the initial bulk factor, but the residual bulk factor was basically stable at 1.26, so the settlement of composite roof was large after gob - side entry remaining. The stability time of fallen gangue increased with the increase of the buried depth. Large fallen gangue had an obvious impact on the gangue retaining, and the small fallen gangue was characterized by flow deformation during compression. The stabilized force model of the fallen gangue was established, and lateral stress of the gangue to the gangue support and the supporting force of the roof were analyzed and calculated. It is proved that the law of the fallen gangue has an important influence on the roof stability.
出处
《煤炭工程》
北大核心
2017年第11期94-98,共5页
Coal Engineering
基金
国家自然科学基金面上基金资助项目(51479195)
关键词
切顶卸压
沿空留巷
冒落矸石
碎胀规律
力学特性
roof cutting and pressure releasing
gob side entry retaining
fallen gangue
bulking rule
mechanical characteristics
