针对当前隧道超前地质预报工作中不能对于掌子面前方的水患进行有效预报的情况,笔者提出一种基于浮动薄板理论的隧道掌子面前方不良地质体的瞬变电磁波场变换延拓成像的超前预报有效方法,引入比较合适的三维的虚拟速度连续分析方法,解决了偏移成像中对实测资料的速度提取问题。给出了瞬变电磁方法在隧道中适用的工作方法。对理论模型和应用实例都进行了分析计算,得到的结果与实际情况相符合,表明该速度分析方法是切实有效的。
In view of the fact that tunnel advanced geological prediction cannot effectively predict the flood in front of the tunnel face,this paper proposes a new method,i.e.,transient electromagnetic wave-field transform continuation and imaging,which is based on the theory of floating plate and has proved to be very effective in predicting the unfavorable geological body in front of the tunnel face.With this desirable 3-D virtual velocity continuous analysis method,the problems of velocity extraction of observed data in migration imaging can be well solved.This paper puts forward the suitable working method of transient electromagnetism for the application in tunnel.In addition,the theoretical models and application examples were analyzed and calculated,and the results obtained coincide with the actual situation,showing that this velocity analysis method is feasible and effective.