Study On The Seismic Behavior Of PHC Pipe Piles Applied For High Pile Wharfs

The prestressed high-strength reinforced concrete pipe piles,that is PHC pipe piles,are most used in high-pile wharfs,but easily damaged under earthquakes.The seismic performance of PHC pipe piles affects the seismic performance of high-pile wharfs,so how to improve the seismic performance of PHC pipe piles is the key to solving the seismic problem of high-pile wharfs.Based on an example of a high-piled wharf,this paper analyzes the force and deformation of PHC pipe piles in high-piled wharf under earthquakes,and studies the main influencing factors of the seismic performance of PHC pipe piles.Based on this,the design and application of PHC pipe piles are developed.The main research contents are as follows:The seismic finite element model for high-piled wharf is established and analysed.Based on an example of a high-piled wharf project,a finite element model of the high-piled wharf was established using the finite element analysis software of ABAQUS to simulate the whole process under earthquake,and the distribution of the force and deformation of the PHC pipe pile were analyzed.The results show that the horizontal displacement of the piles of the PHC pipe pile are not uniform,but the change trend is basically the same.It increases approximately linearly from the bottom to the top of piles.The maximum value are at the top and consistent,and the minimum value are at the bottom and gradually decrease from the seafront to the near land side.The vertical displacement are not uniform,and gradually decrease from the seafront to the near land side.The trend of the bending moment and shear force of the piles are differentat the interface of the soil layer and the pile body and decent interface of piles and soil,and the abrupt change increase from the sea side to the near land side.The maximum value of the bending moment and shear force of the pile body appears near the pile top,the soil layer interface or the soil pile interface.The main factors affecting the seismic performance of PHC pipe piles are studied.Aiming at the pile diameter,wall thickness,section shape and pile length of PHC pipe piles,the method of controling variable was used to analyze the influence of each controllable factor on the seismic performance of PHC pipe piles in high-piled wharfs.The results show that with the increase of the diameter and the thickness of the wall,the displacement of the piles decreases,and the bending moment and shear force increase.When the shape of the pile section is different,the forces and deformation of the hollow round pile are the most uniform and the change value is relatively small.The shape of the cross section of the pile is the best.As the pile length increases,the force at the bottom of the piles increase.Based on the above analysis,the research about the design and application of PHC pipe piles are carried out.Combined with the results of engineering examples,design suggestions are proposed that different pile positions with different pile diameters,composite piles that are partially hollow,and different pile positions with different pile lengths,which provide reference for actual engineering construction.