Research On Seismic Wave Combination Detector Method For Explorating Carst Cave Under Bridge Pile

In the carst development layer, the bridge pile construction would cause a lot of questions including sticking, drill falling, slurry lose, hole wall collapse, and the carst cave under the bridge pile would affect the safty of the bridge.Shallow seismic exploration (less than 200m) is a geophysical method which studys the shallow part of the geological structure, according to the propagation law of the artficial excitation seismic wave in rock and soil media. Shallow seismic exploration has small working area, high exploration resolution in theory, but complicated interference factor in shallow layer which makes exploration resolution lower in fact.This paper, based on the theory of the shallow seismic exploration technology, uses the principle of the combination detector tu overcome the disadvantages of the observation which is interfered seriously by the sound wave and surface wave, combined with the engineering geological condition of the jinhe super large bridge in Zhaozhuang section of Beijing-Shanghai high-speed railway. This paper improves exploration resolution and establishs a seismic wave methed which explorates the size of the carst cave, using the principle of combination detector, gives the feature image of seismic of the carst cave and the correlation of the carst cave depth and the seismic wave period. The actual situation of the bridge pile construction shows that this method is feasible to explorate the carst cave under the bridge pile and has a high exploration resolution.