广州建筑 ›› 2020, Vol. 48 ›› Issue (5): 8-.

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单孔地震波法在既有桥梁基桩工作状况评估中的应用研究

  

  • 出版日期:2020-10-10 发布日期:2020-11-16

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

  • Online:2020-10-10 Published:2020-11-16

摘要: 本文通过广州地区上埗桥(旧桥)既有基桩检测工程案例,对单孔地震波在既有桥梁基桩检测中的应用进行了研究。应用结果表明:上埗桥2#桥墩三根桩桩长满足原设计要求,桩身无明显缺陷,采用多道水听器的单孔地震波法可较好地对既有桥梁基桩桩长及明显缺陷进行探测;采用纵向激振时(盖梁上敲、支架竖敲),地震波首波初至时间和振幅相比横向激振(桩身横敲)更加清晰,便于对检测结果的判读;借助桩侧钻孔揭露地质状况,并对基桩承载力进行验算发现,2#桥墩P2-1、P2-3号基桩承载力计算值满足原设计承载力要求,P2-2号基桩承载力计算值比原设计值降低约26%(514kN)。

关键词: 既有建筑物, 基桩检测, 单孔地震波法, 完整性, 承载力

Abstract: 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).

Key words: existing buildings, foundation pile detection, single-hole seismic wave method, integrity, bearing capacity