Nonlinear Finite Element Analysis For Seismic Response Of High-Pile Wharf Structure

Thanks to the introduction of our reform and opening-up policy since 1978, a large number of water conservancy, transportation and civil engineering structures have been built. The infrastructure construction in China has been entering the peak period including port engineering which connects the land and marine transportation. The high-pile wharf is widely used as a common harbor engineering structure in port construction in China. Many domestic and abroad papers show that the high-pile wharf structures are susceptible to damage. The seismic research on the high-pile wharf structures has great significance to ensure the safety of high pile wharf structures and reduce economic loss. In this paper, According to the characteristics of ABAQUS, seismic response in finite element analysis of high-pile wharf structures is studied in details. The main contents are as follows:(1) In order to obtain the displacement and internal forces of the high-pile wharf structures under the strong earthquake, three dimensional model of high-pile wharf is set up with ABAQUS software. In the paper Master-Slave contact surface is used to describe interaction of piles-soil, and embedded element is conducted to simulate interaction of steel which possesses the nonlinear characteristics and concrete based on the plasticity model damage. What’s more, Drucker-Prager criterion is employed to simulate the elastoplasticity of subsoil. So nonlinear time-history analysis theory is employed to analyze the nonlinear seismic response for the high-pile wharf. In the process, the results of the calculation include the horizontal displacement response, bending moment and shear force distribution. At the same time the regularity of the structural stress and residual displacement of subsoil are also summarized and discussed. Furthermore, the force effects on the overall high-pile wharf structures under the different seismic waves are compared and analyzed. The linear and nonlinear numerical computation is summarized to distinguish the difference. The results show that that the junction of bank soil and pile top are dangerous position of piles which is susceptible to enter the plasticity condition. The Comparison considering material linearity and nonlinearity states that the gap of the pile internal force ranges from 9.0%-72.2%. So it is very important to consider material nonlinearity to optimize the design of the high-pile wharf and accurately evaluate the seismic resistance capacity.(2) The control variable method is adopted to investigate the bank soil strength and batter pile layout on seismic performance of the high-pile wharf by comparing the horizontal displacement response of the structure and the pile internal force. The studies indicate that the increase of soil strength can effectively reduce the horizontal displacement response of the standing-pile wharf and pile internal force. The horizontal displacement, bending moment and shear force can be decreased about 11.2%-27.8%, if the bank soil strength is doubled. The batter pile can effectively reduce the horizontal displacement of high-pile wharf. The horizontal displacement of batter pile wharf was only about two-thirds of all straight pile wharf structure and it also has obvious effect on reducing the internal forces of the piles. But the batter pile wharf increases the residual displacement of soil which is very negative for post-earthquake reconstruction work.(3) In order to understand the effect of number of piles on seismic performance of high-pile wharf structure, five and seven piles-wharf structure is researched on the basis of original wharf structure. The nonlinear time-history analysis is used to compare these two structures. The following conclusions display horizontal displacement, bending moment and shear force decrease about one third if the number of piles is increased from 5 to 7.