关键词: 断层围陷波, 活断层, 断层破碎带, 汤西断裂

Abstract: As the first application of fault zone trapped waves to the active fault exploration in urban areas,an experiment aimed at Tangxi Fault of Taihang Mtns.Fault Belt was performed with explosion sources.By using digital filtering,spectral analysis and other techniques,the fault zone trapped waves were separated from seismograms.Based on the observational data of two transverse profiles,the position of the fault was detected,and its width was assumed to be 200～300m.The great width of the fractured zone may be due to the tensional action.The normal dispersion nature of the fault zone trapped waves was revealed from multiple band-pass filtered seismograms.The waves with lower frequencies travel faster than those with higher frequencies.This indicates that the fault zone trapped waves are surface waves and their dispersions can be used to study physical properties of the medium in the fault zone.The results also show that the fault zone trapped waves can be formed and propagate not only in new fractured zones,but also in old faults.Indeed,they can be generated if the physical properties of the mediums inside and outside the fault zone are quite different.The method using fault zone trapped waves is of great advantage for active fault exploration,especially in urban areas.

Key words: fault zone trapped waves, active fault, fractured zone, Tangxi Fault