基于属性数学理论的隧道瓦斯突出危险性评价

Evaluation of Tunnel Gas Outburst Based on Attribute Mathematical Theory

以贵州山区某过煤层瓦斯隧道为例,根据影响隧道瓦斯突出的关键地质因素,选取瓦斯压力、瓦斯含量、瓦斯放散初速度、煤的坚固性系数、煤体结构类型等参数作为隧道瓦斯突出评价的关键指标,采用属性数学理论建立隧道瓦斯突出危险性预测模型,对隧道瓦斯突出危险性进行了评价。在模型构建过程中,首先依据隧道瓦斯突出危险性分级标准,构建各评价指标的属性测度函数,进而结合隧道施工现场实测的相关指标参数,计算各煤层的单指标属性测度及综合属性测度,建立起评价指标测度与属性之间的关系,最后利用置信度对多因素影响下瓦斯隧道的综合属性进行判识,进而实现对隧道瓦斯突出危险性的评价。评价结果显示:过煤层隧道穿越M5、M9煤层时,隧道具有强突出危险性,穿越M4煤层时隧道突出危险性相对较小,隧道施工过程中应加强M5、M9煤层的消突和防突措施,以防灾害事故的发生;评价结果与工程现场显示的瓦斯动力现象相一致,具有较高可信度。

Taking instance from one gas tunnel passing through coal beds in Guizhou mountain areas and based on the key geological factors affecting gas outburst in tunnel,the key geology factors including gas pressure,gas content,initial speed of gas diffusion,the strength of coal and coal-body structure were chosen as evaluation parameters. The risk prediction model of gas outburst was established by using attribute mathematics theory with those key geological factors,and then the risk of the gas outburst in the tunnel was evaluated by the model. In the process of model building,according to the level classification of parameters associated with the tunnel gas outburst,the attribute recognition function of each key parameter was firstly established. And then,combined with the field measured data,both the signal index attribute measure and comprehensive attribute measure for tunnel gas outburst risk evaluation were calculated by the confidence function. Finally,the comprehensive attribute of gas tunnel under the influence of multiple factors was identified by using the confidence coefficient and the risk of the gas outburst in the tunnel was realized. The evaluated results show that the tunnel have great possibility of gas outburst risk passing through the M5 and M9 coal beds. But the tunnel has little possibility of gas outburst risk passing through the M4 coal bed. Therefore,special safeguard procedures should be taken to M5 and M9 coal beds for prevention of the possible gas outburst. The evaluated results based on the attribute mathematical theory meet well with the dynamic omen of gas outburst in the field practice,which shows that this theory can be used as a reliable method.