The Research On Static Performance Of Prestressed High-strength Concrete Pipe Pile (PHC Pile) And Application Engineering

As a new kind of pile foundation,prestressed concrete pipe piles have been greatly developed since the beginning of last century.It has been widely used in various building foundations and played an important role.As an important component of pile foundation,prestressed concrete pipe piles have always been the focus of attention of the buildings and bridges and can be divided into the prestressed concrete pipe pile(PC pile),prestressed concrete thin-wall pipe pile(PTC pile)and high-strength prestressed concrete pipe pile(PHC pile).Although it has many advantages,there are still many deficiencies.It is necessary to study the prestressed high strength concrete pipe pile(PHC pile).Based on the research of the construction of high-strength prestressed concrete pipe piles in Hefei,studies are conducted as follows:(1)This paper summarized the current situation and key problems of prestressed concrete pipe piles.The development history of prestressed concrete pipe piles is summarized.And the construction technology of prestressed concrete pipe pile is also expounded.The construction quality and accuracy control method of prestressed concrete pipe piles are also put forward.The status of static loading behavior of prestressed concrete pipe piles is summarized.(2)There static loading tests were conducted on the prestressed high strength concrete pipe piles to check the designed bearing capacity.Through the Q-s curves and the S-lgt curves of the vertical static loading tests,the ultimate bearing capacity of the pipe piles is determined which provides the basis for the later design.(3)The in-depth study of the prestressed high strength concrete pipe piles is developed by using finite element software ANSYS.The finite element analysis results agree well with the tested results which prove the accuracy of the FE models.Five parameters including the pile length,diameter,wall thickness,concrete strength,no-prestressed reinforcing steel bar are considered to explore the effects on the piles which provide some advice in the engineering application in the future.(4)This paper introduced the prestressed high strength concrete pipe pile project in Hefei.The supervision process and quality requirements of prestressed high strength concrete pipe pile project are put forward.The existing problems of piles are summarized,and the corresponding solutions are also put forward.Several main detecting techniques of the piles are put forward.And three stages of quality control of prestressed concrete pipe pile are detailed.