深部下组煤首采面带压试采奥灰突水危险性分区评价

为了探究华北型煤田深部下组煤底板带压开采安全可行性,以济北矿区某煤矿高承压水体下组煤首采面采掘为工程背景,结合在该面施工的9个奥灰钻孔和1个奥灰水文观测孔资料,运用突水系数法和底板岩层综合阻水强度法对正常块段奥灰突水的危险性进行预测评价与分区。分析表明奥灰突水值大于0.1 MPa/m的区域存在2处；而根据底板岩层综合阻水强度法计算，各个钻孔的综合阻水强度值均大于相应的实际水压值,并把实际水压值与其相应的综合阻水强度值作比值进行分析。2种方法对比分析表明,奥灰突水系数偏大的险区和实际水压与其相应的综合阻水强度的比值大的分布区域基本重合,比较符合实际情况。这为济北矿区及地质条件相似矿井煤炭资源向深部带压开采所引起的底板水防治提供了新的评价方法。

Evaluation of Ordovician Limestone Water Inrush Risk Zoning for First Working Face under High Pressure of Deep Under-group Coal Mining

In order to explore the feasibility for safe mining under pressure of North-China-type deep lower-group coal seam floor，with the first working face of the lower-group coal with high pressure water in Jibei mining area as an engineering background，combining with nine Ordovician limestone boreholes′ and one Ordovician limestone hydrological observation hole′s data，predicting assessment and zoning of the Ordovician limestone water inrush risk at normal block were analyzed with the water inrush coefficient method and integrated water blocking strength method of floor strata.The analysis showed that there are two regions with the Ordovician limestone water inrush values greater than 0.1 MPa/m.But according to the comprehensive water blocking strength calculation of floor strata，the integrated water blocking strength value of each borehole was greater than its corresponding actual pressure value，and then the ratio of actual pressure value to its corresponding integrated water blocking strength is analyzed.The results indicated that if Ordovician limestone water inrush coefficient is larger，the region with big ratio value of the actual water pressure to its corresponding integrated block water intensity just exists in dangerous zone.It is line with the actual situation.This research provides a new evaluation method for the floor water control during the transition to deep exploitation of coal resources under pressure in Jibei mining area or other areas with similar geological conditions.