高瓦斯隧道穿越煤系地层段TSP法超前探测

TSP geological prediction of high gas tunnel crossing coal measures formation

地震波反射法(TSP法)因兼具探测距离远和分辨率高的特点,在隧道超前地质预报中得到广泛应用。但是一直以来TSP法在高瓦斯隧道煤系地层段的应用相对较少,处于被弱化的位置。这里首先分析了影响TSP法在煤系地层段实施的因素,然后提出相应的对策提高TSP法在煤系地层实施的高效性,最后结合同一高瓦斯工区的两个典型案例,对比分析地震波波速、泊松比和弹性模量等物理力学参数的变化规律,探讨地震波相关参数异常和煤层分布范围的对应关系。结果表明,地震波低速异常区和高泊松比特征可判释厚煤层的大致分布范围,TSP法对煤层的有效探测,能为超前钻孔验证提供重点靶区,对隧道施工掘进创造有利条件。

Seismic wave reflection method（TSP method） has been widely used in geological prediction of tunnel because of characteristics of far detection distance and high resolution. However, the application of TSP method in the coal seam of high gas tunnel has been less, and has been weaken. Firstly, this paper analyzes the factors that influence the implementation of TSP method in coal measures strata, and then puts forward the corresponding countermeasures to improve the efficiency of TSP method in coal measure strata. Finally, through two typical cases with a high gas area, comparative analysis the changes of physical and mechanical parameters, such as seismic wave velocity, Poissons ratio and Elastic modulus, etc.,discuss the cor-responding relationship between the abnormal parameters of seismic wave and the distribution of coal seam. The results show that the low velocity anomaly area and high Poissons ratio can be used to interpret the distribution of thick coal seam, the effec-tive detection of coal seam by TSP method can provide a key target area for the advanced drilling, and create favorable condi-tions for the tunnel construction.