巷道掘进中地震超前探测波场特征研究

Study on Seismic Advanced Detection Wave Field Characteristics in Roadway Heading

用交错网格有限差分法对激发点置于迎头远端一炮多收系统煤巷内不同地质模型中的弹性波场进行了数值模拟,分析了不同地质模型中的波场特征。研究表明:采用激发点置于迎头远端底板激发底板接收的观测接收方式可以有效排除顶板波的干扰;工作面前方构造界面反射波清晰且表现为负视速度,可通过视速度滤波进行识别提取;工作面绕射波为主要干扰,其出现位置可预测和波列较宽是区别于前方构造界面反射波的主要特征。

This paper makes numerical modeling of seismic wave field in the advanced detection surveillance system that the shotpoint is away from the coal face by applying staggered grid finite difference method, and seismic wave field characteristics of various wave pat- terns in difl＇erent models are analyzed. As a result, the interference wave in the roof can be eliminated effectively when the shotpoint is on the floor; reflected waves of geological interface are clear and show negative apparent velocity, so it can be recognized and extracted by using apparent velocity wave filtering; the diffraction wave of coal face is the main interface wave, the diffraction wave train is wider than other waves and it is predictable.