Numerical Analysis Of The Bearing Performance Of Stiffness Filling Core High Strength Concrete Pipe Piples Under Horizontal Cyclic Loading

Prestressed concrete pipe piles reflect the rapid development of concretetechnology and the continuous improvement of the level concrete products.Under the strong earthquake, top of the pile of the pile foundation will be therole of the larger shear and bending moment. The seismic performance of hollowPHC piles usually used project is poor, prone to brittle fracture affect the overallstability. Pouring high strength concrete in the steel cage filling core inconstruction can improve the seismic performance. Although the bearingcapacity of whole pile has increased, but the juncture of its pile and pile cap stillcannot meet the seismic requirements. The stiffness filling core pipe pile is usinga combination of steel reinforced concrete structures instead of ordinaryreinforced concrete to fill the core, with the advantages of light weight, highcapacity and good shock resistance. It can enhance the level bearing capacity and energy dissipation capacity of the pile, and improve the integrity of piles,thus to improve the seismic capacity of the pile and the rapid development of thebuilding structure.With the improvement of building safety and durability requirements,theoretical calculations before building design is becoming increasinglyimportant, the development of the computer gradually brought the finite elementsimulation software in engineering calculations,ABAQUS software is an finiteelement software that commonly used actual engineering simulation. Its scopeof solving the problems is very broad, from the relatively simple linear analysisto the relatively complex nonlinear problems. The various load conditionschange in environment and the surroundings change are also able to simulate. Inthis paper, the horizontal bearing capacity and ductility characteristics underhorizontal cyclic loading have been simulated in use of this software among theordinary filling core PHC pipe piles, the stiffness filling core PHC pipe piles andthe variable parameters stiffness filling core pipe piles. Then adjust the pileparameters to obtain the optimum combination of parameters, and make stiffnessfilling core with concrete optimal combination to meet project requirements.The results show that:(1) The overall carrying capacity is little of ordinary filling core PHC pipepiles under horizontal seismic loads. Its node with poor ductility is easy todestroy, and need to select the appropriate way to strengthen it.(2) The formula have been put forward between the stiffness filling core pipe piles with the pile cap junction, combining many scholars’ derivation ofpile and pile cap connection. Then it are verified by the simulation results, andthe simulation results are consistent.(3) It can improve stiffness of the pile by setting the stiffness filling core inthe pile and steel and concrete combining with each other, thereby increase thelevel of the bearing capacity of prestressed pipe. Because the stiffness fillingcore have enhanced the connectivity between the caps and the pile junction, itimproved the ductility and energy dissipation capacity, thus improve the seismicperformance of the pile.(4) With the increase of the core strength of the filling depth, and theincrease the length of the horizontal and vertical beam, its carrying capacity hasimproved, but only slightly. Therefore, when the bearing capacity has met therequirements, the position and the cross-sectional area of steel have been themain parameters affecting the seismic performance.