煤与瓦斯突出预测的一个新指标

A new prediction index of coal and gas outburst

煤与瓦斯突出是煤矿主要瓦斯灾害事故类型之一。目前,国内煤与瓦斯突出预测主要是根据瓦斯动力现象特征和基于煤层瓦斯压力、煤的破坏类型、坚固性系数与瓦斯放散初速度的四参数法。四参数法规定,4个参数均超过各自的临界值才能定为突出煤层;瓦斯压力的临界值为0.74MPa。但实践表明,瓦斯压力小于0.74 MPa也曾多次发生突出。本文用可压缩流体力学的观点分析了突出机理;采用多相连续介质力学中的应力分析法建立了煤与瓦斯突出预测的一个新指标F,并给出了有关参数的计算方法;案例分析表明,所得结果符合实际。

At present, the main methods for predicting outburst in China are mainly based on gas dy- namic phenomena and the so-called four-parameter method （e.g. gas pressure of coal seam, failure mode of coal mass, hardiness coefficient of coal mass, and initial diffusion velocity of gas）. The four-parameter method requires that coal seam should be confirmed as outburst seam only if all of the four parameters exceed their alternative critical values, and the critical value of gas pressure is 0.74 MPa. However, practices show that outbursts had happened even though the gas pressures were less than 0.74 MPa. In this paper, the outburst mechanism was overviewed by compressible fluid mechanics, and a new predicting index F was established by using the stress analysis method of multi-phase continuum mechanics. In addition, calculation method for determining the related parameters was also given. Case studies reveal that the formula accords well with the practice.