煤炭采空区处理的新方法与实例分析

Coalmine Gob Area Control New Method and Case Study

位于乌鲁木齐市南湖路以西的煤炭采空区面积达67 100.5m2,区内构造从南到北主要由八道湾向斜和七道湾背斜组成,地层产状变化不大。该矿区开采较深,且采空区塌陷区有明显的地下水活动迹象。在对深孔大体积采空区注浆时,比较各种常见注浆治理方法,均存在不同的制约因素,故决定采用灌浆爆破压密法对采空区进行压实加固。经现场爆破试验,该区重复爆破次数在3～5次左右。灌浆爆破压密处理后,对不同土层进行取样对比分析,得到其相应密度(增加)及空隙比(减少)的变化分别为:杂填土14.1%,-7.9%;素填土5.9%,-3.3%;塌落煤层7.8%,-7.7%。根据压缩数据及现场测量,处理后的土体沉降2～4m,部分空体地段的沉降量达10～20m,治理效果明显。

The 67100.5m2 coalmine gob area is located at west of Nanhu Road, Urumqi City. Structurally from north to south is composed of Badaowan Syncline and Qidaowan anticline and no major changes in strata occurrences. The working depth is rather deep in the mining area, and obvious groundwater activity evidences existed in gob collapsed area. When grouting in deep large size gob area, different constraint factors are existing in common grouting control methods, finally blasting compaction is used. After site testing, the blasting number needed in the area is 3-5 times. Contrastive analyses to different soils after grouting blasting compaction, the changes of corresponding density （increased） and void ratio （reduced） are： miscellaneous fill 14.1%, -7.9%; plain earth fill 5.9%, -3.3%; caved coal 7.8%, -7.7% respectively. According to compaction data and site measurement, soil settlement after processing is 2-4m, settlement in parts of gob areas can be 10-20m, so that the control effect is obvious.