瓦斯压力测定时间及其受控因素分析

提前掌握瓦斯压力测定所需时间,对准确高效地测定煤层瓦斯压力非常重要。以被动式岩巷测压为例,在初步分析测压钻孔周围煤体初始瓦斯压力分布规律、游离瓦斯与吸附瓦斯的关系、瓦斯流量衰减规律及瓦斯流场平衡条件的基础上,从理论上推导出瓦斯压力测定时间计算公式。将该公式与现场瓦斯压力测定监测数据进行对比分析,并研究瓦斯压力测定时间的影响因素。结果表明,理论分析结果与现场瓦斯压力测定情况基本一致,测压时间的误差仅为6%;改变测压钻孔初始气体压力(主动式测压)是唯一有实用价值的方法。

Analysis of Gas Pressure Measurement Time and Controlling Factors

It is very important for measuring gas pressure exactly and efficiently to know gas pressure measurement time in advance.Taking passive gas pressure measurement in the rock tunnel for example,on the basis of analyzing the initial gas pressure distribution rule in the coal lying in the surround of drill hole,the relation of free gas and adsorption gas,the reduction rule of gas flux and the condition of gas flow field equilibrium,a computational formula of gas pressure measurement time was obtained.A comparative analysis was conducted of the formula and monitoring data of gas pressure measurement in mine.Finally,the factors influencing gas pressure measurement time were studied.The result shows that the analysis result in theory is consistent basically with the status of gas pressure measurement in mine,and the error of gas pressure measurement time is only 6%;changing the initial gas pressure in gas pressure measurement drill hole(active gas pressure measurement) is the sole practical method.