The Application of Single-hole Seismic Wave Method in the Assessment of the Working Status of Existing Bridge Foundation Piles

In this paper, the application of single-hole seismic wave in the detection of existing bridge foundation piles is studied through the case study of ShangBu bridge (old bridge) in Guangzhou.The application results show that the three pile lengths of No. 2 bridge piers in ShangBu bridge meet the original design requirements, and the piles have no obvious defects. The single-hole seismic wave method with multiple hydrophones can be better to used to detect the pile lengths and obvious defects of existing bridge foundations.In addition, when longitudinal excitation is adopted (knock on the cover beam, vertical knock on the support), the first arrival time and amplitude of seismic wave are clearer than that of lateral excitation (knock on the pile), which is convenient for interpretation of detection results.By means of the geological conditions exposed by the pile side drilling and the checking calculation of the pile bearing capacity, it is found that the calculated bearing capacity of No.2 bridge pier P2-1 and No. P2-3 pile meets the original design bearing capacity requirements, and the calculated bearing capacity of No. P2-2 pile is about 26% lower than the original design value (514kN).