Abstract:

In seismic exploration, especially in shallow seismic exploration, tomography and seismic wave method, the first arrival time picking accuracy directly affects the inversion results of the exploration area geological structure. The automatic pickup of the first arrival time is also a key seismic data processing node in tunnel advance geological prediction. In this paper, 4 first arrival time automatic pickup algorithms, namely maximum amplitude algorithm, energy ratio algorithm, STA/LTA algorithm and AIC algorithm, are introduced; and the 4 algorithms are compared and analyzed based on a set of seismic data collected using the preearthquake prediction of a tunnel in Yunnan. The results show that the first arrival time of the SLA/LTA algorithm is more accurate, followed by those of the AIC method and the energy ratio method. And same conclusion is obtain by comparing and analyzing other sets of data collected by the tunnel advance geological prediction.

Key words: tunnel, advance geological prediction, first arrival time automatic pickup, SLA/LTA algorithm, seismic wave method