Prestressed Concrete Cylinder Pipe (PCCP) is used in the Huining section in Beijing in the middle route of the South-to-North Water Transfer Project.After having worked for a long period,the PCCP pipelines have successively suffered the damage of wire breakage,concrete cracking,and local uneven subsidence.Aiming at the common engineering geological defects of the PCCP pipelines used in the Huining section,this study carried out shallow seismic tests based on the high-density seismic imaging exploration and the Rayleigh wave method.As a result,the physical properties of the PCCP and cushion areas were obtained,accurate troubleshooting of the fractures developing on the pipe wall and geologically uncompacted areas were performed, thus providing valuable experience for the investigation of the damages to PCCP.