煤层底板原位综合测试及突水危险性评估

INTEGRATED IN-SITU TESTS FOR WATER INRUSH POSSIBILITY EVALUATION IN COAL SEAM FLOORS

在实施井下钻孔水压致裂地应力测量的同时,评价岩层阻水性能,确定导升带高度,做到一孔多用。测试区实际观测表明,泥岩、粉砂岩、中砂岩、灰岩阻水性能由大到小,导升高度则由小变大,平均导升高度约3.2m;地应力测量表明,该测试区原始地应力状态为SH>Sv>Sh,最大水平主应力方向NE至NEE。突水临界指数评价表明,-550m水平采煤工作面掘进时突水的可能性较大,应当采取防范措施。

In a single hole with multi-purposes,the evaluation ability of water-resistance and confirming progressive intrusion height can be put in practice during the process of geostresses tests with the in-situ hydraulic fracturing method in mining working faces or roadways.Test results in practice show that the abilities of the water-resistances of mudrocks,fine sandstones,middle sandstones,limestones are from large to small.The progressive intrusion heights are from small to large.The abilities of the water-resistances of strata in the floor Nos.11,10,7,8 of the coal seams are from large to small.The strata stabilities in the floor Nos.8,11,7,10 of the coal seams are also from large to small.Geostress tests with the in-situ hydraulic fracturing method indicate that the original geostress states are SH〉Sv〉Sh.The directions of the maximum horizontal stress are from NE to NEE in this area.The water inrush critical index evaluation shows that the water inrush possibility is higher as the coal extraction into the-550m level.Preventive measures should be undertaken earlier.