CURRENT STATUS AND PROSPECTS OF TEST TECHNIQUES FOR PRESTRESSED HIGH STRENGTH CONCRETE PIPE PILE

There are many difficulties in testing the mechanical properties of prestressed high strength(PHC)pipe pile, because of the complicated production process, unique pile structure and large pile resistance. At present, the test techniques for testing the mechanical properties of PHC pipe pile can be divided into four categories: point monitoring, linear monitoring, distributed optical fiber monitoring, and quasi-distributed fiber bragg grating monitoring. This paper summarizes the principle, advantages and disadvantages, application status of the test technology for PHC pipe pile, as well as the installation method of related sensors. It further discusses the problems existing in the test technology and installation method. The analysis indicates that distributed optical fiber monitoring and quasi-distributed fiber bragg grating monitoring have higher test accuracy, wider monitoring range and better monitoring results. The coordination of deformation between optical fiber and pile body, survival rate of the installed fiber and impact of installation on PHC pipe pile are the hot research topics in the future.