煤与瓦斯突出预测敏感指标及其临界值研究进展

煤与瓦斯突出预测是突出煤层2个"四位一体"综合防突措施的关键环节,对确定突出预测敏感指标及其临界值具有重要意义。以往突出预测敏感指标及临界值的确定,包括地应力指标和瓦斯指标,是通过现场反复测试、试验确定的;而现今的突出防治管理模式不支持这种方法,故只能采取实验室试验研究,主要是针对瓦斯相关指标的研究,结合部分现场验证来确定。选取大隆矿12煤、芦岭矿8煤、祁南矿3煤、朱仙庄矿10煤、童亭矿7煤和新景3煤等6个煤样,煤种涉及中等变质程度的气肥煤到高等变质程度的无烟煤,试验研究了各煤样瓦斯压力P与瓦斯含量W,瓦斯压力P与钻屑瓦斯解吸指标K_1和Δh_2,以及钻屑瓦斯解吸指标K_1与Δh_2之间的关系规律。结果表明:突出预测的瓦斯指标之间具有单值对应关系,但各煤样的这种对应关系是变化的,国家相关标准给出的突出预测指标建议临界值之间并不对应,也不能完全反映煤层的实际突出危险性与突出严重程度,不同变质程度煤层很难存在统一的临界值;应用煤层瓦斯相关指标之间的对应关系,结合突出煤层的实际,如始突深度、突出动力现象、钻孔动力现象等,可间接确定突出预测敏感指标的临界值。同时,未来精细化的突出防治对突出预测敏感指标有更高的要求,进一步研究的方向应包含反映地应力状况、小构造影响下煤层赋存、预测煤层潜在突出强度的指标,以及适应突出灾害差异性的新突出预测方法及措施效果检验方法。

Research progress of sensitive index and critical values for coal and gas outburst prediction

Coal and gas outburst prediction is the key link of two“four-in-one”comprehensive outburst prevention measures for outburst coal seam.It is of great significance to determine the sensitive index and critical value of outburst prediction.In the past,the determination of sensitive indexes and critical values of outburst prediction,including in-situ stress index and gas index,were determined through re?peated field tests and experiments.However,the current outburst prevention and control management model does not support this method,so laboratory experiments can only be used mainly for the study of gas-related indicators,combined with part of the field verification to de?termine.In this paper,six coal samples were selected from No.12 coal seam of Dalong Mine,No.8 coal seam of Luling Mine,No.3 coal seam of Qinan Mine,No.10 coal seam of Zhuxianzhuang Mine,No.7 coal seam of Tongting Mine and No.3 coal seam of Xinjing Mine.The coal types range from medium metamorphic gas and fat coal to high metamorphism.For anthracite coal,the relationship between gas pressure P and gas content W,gas pressure P and gas desorption index K1 andΔh2,as well as drilling cuttings gas desorption index K1 andΔh2 are studied experimentally.The results show that:there is a single value correspondce between the gas indicators for outburst prediction,but the corresponding relationship of each coal sample is changing.The proposed critical values of outburst prediction indexes given by relevant national standards do not correspond to each other,nor can they fully reflect the actual outburst risk and outburst severity of coal seams.It is difficult to have a unified critical value for coal seams with different metamorphic degrees.The critical value of the sensitive index of out?burst prediction can be indirectly determined by the corresponding relationship between the gas related indexes of coal sample and the real?ity of outburst coal seam,such as the initial outburst depth,outburst dynamic phenomenon and drilling dynamic phenomenon.At the same time,the future refined outburst prevention and control will have higher requirements for the sensitive indicators of outburst prediction.The further research direction should include indicators that reflect the ground stress status,coal seam occurrence under the influence of small structures,prediction of coal seam potential outburst strength,and new outburst prediction methods and measures adapted to the differ?ences of outburst disasters.