基于指数平滑法的非煤系地层隧道瓦斯涌出量预测方法

Prediction Method of Gas Emission Caused by Tunnel Excavation in Non-coal Bearing Strata Based on the Exponential Smoothing Method

分析非煤系地层瓦斯在隧道开挖作用下的涌出特征,阐明指数平滑法的计算原理,并将其应用于七曜山隧道瓦斯涌出量预测。结果表明:非煤系地层隧道瓦斯涌出位置及时机具有随机性,但涌出过程具有一定延续性,可将瓦斯涌出量视为具有一定依存性的时间序列;指数平滑法可以通过改变历史时程数据的权重关系来对预测结果进行不断优化,适用于非煤系地层瓦斯隧道;七曜山隧道为高瓦斯隧道,二次指数平滑法的预测误差在3%以内。

The emission characteristics of gas in non-coal bearing strata in tunnel excavation were analyzed.The calculation principle of exponential smoothing method was then explained.Finally,the method was applied to the prediction of gas emission amount in the Qiyaoshan Tunnel.The results showed that:In non-coal bearing strata,the gas emission position and occasion caused by tunnel excavation are random,but the emission process has certain stability and continuity,so it is suitable to regard the gas emission as a time series with certain dependence and correlation.The exponential smoothing method can optimize the prediction results by changing the weight relationship of the existing timing history data of gas emission amount,hence it is suitable for predicting the gas emission amount of tunnels in non-coal measures strata.The Qiyaoshan tunnel is a high-level gas tunnel and the prediction error of the quadratic exponential smoothing method is less than 3%.