Nonlinear Analysis Of Seismic Response Of Cross Sea Bridge In Bohai Sea Area

In this paper,based on the proposed Qinhuangdao-Dalian cross-sea channel project,in view of the non-navigable holes bridge,considering the nonlinear properties of the soft soil site,and a elastoplastic hysteresis spring model is proposed.The time history analysis of the response of bridge under earthquake load is carried out.Besides,the influence of structural parameters and design parameters is also analyzed.The first chapter is the introduction,which mainly describes the background of the research and the related progress of pile and soil research.First,the project is based on the cross-sea channel project linking Qinhuangdao and Dalian,and gives a brief description of the project planning and project design.Pointing out the main problems in the project,including soft soil foundation,ice load and earthquake,among which the most important is the soft soil foundation simulation.Then,the related researches in the field of pile and soil are sorted out,and the differences between existing research and engineering application are pointed out too.Finally,putting forward the main contents of this paper.The second chapter first summarizes several commonly used soil models,then uses the ABAQUS software to establish the three-dimensional solid finite element model of the horizontal loaded pile,and calculates the hysteresis curve of horizontal soil resistance to horizontal displacement of the soil at different depths.Combined with the lag system spring built in Midas software,the hysteretic curve of the solid model is processed,and the parameters needed for the hysteretic spring with depth are obtained.Finally,a comparison is made to verify that the spring model can simulate the calculation results of solid finite element well.The third chapter,based on the geological data of Bohai sea area and the design scheme of bridge structure,the parameters of elastoplastic hysteresis spring model simulating the effect of the soft soil in this area is calculated.Midas software is used to establish the threedimensional frame model of the real bridge,taking the inherent properties of the plastic hinge of the pier section into consideration,and the nonlinear response analysis of the structure under the action of the E1 and E2 earthquake is carried out.The results are compared with the linear elastic soil spring model,which proves that both of them have better similarity under the action of small earthquakes,and the hysteretic spring under the action of large earthquakes can consider the energy dissipation effect of the pile and soil better,which has a certain reference significance for bridge structures with fine analysis requirements.The fourth chapter analyzes the influence of structural parameters and design parameters on the basis of design conditions.The results show that the number of the fixed support,the temperature effect,the height of the pier and the seismic fortification intensity have great influence on the response of the structure under the earthquake,but the effect of the span of the main beam is not significant.The fifth chapter is the whole content of this paper,including the shortcomings and further research of this paper.