The Seismic Performance Study Of Cable-stayed In Deep Sea Under Near-field Earthquake

Earthquake is a destructive natural disaster, under the earthquake, structure was severely damaged, caused heavy loss of life and property, therefore, seismic has been one of the problems designers need to consider. In recent decades, many scholars has studied seismic performance of long-span cable-stayed bridges on land under far-field earthquake and achieved rich results, as the expansion of traffic network, the long-span cable-stayed bridges in deep sea are increasingly constructed, the bridge designers are facing a new problem because of the complexity deep-sea environment, as the bridges near seismic zone increased and geological complexity, making the study of near-field earthquake more important, so the seismic performance study of cable-stayed bridge in deep sea under the near-field earthquake in this paper has a certain practical significance.In this paper, using Jiuzhou channel bridge, one part of the Hong Kong, Zhuhai and Macao bridge, as the engineering background, in view of the twin towers, crank arm and central cable planes steel-concrete composite beam, using Midas Civil finite element software to establish the three-dimensional whole model, according to the boundary conditions of pile- soil interaction, isolation bearing, hydrodynamic force caused by earthquake, using the "m" method in the finite element software, lead rubber bearing and additional quality method based on Morison equation consider respectively. Through the establishment of high pile caps cable-stayed bridge and low pile caps cable-stayed bridge model to study the dynamic characteristics of structure, using the response spectrum analysis and time history analysis method for two structure forms of cable-stayed bridge to analyze seismic response and compare them, then draw a conclusion that the internal force response characteristic of cable-stayed bridge under two structure forms; Whether the dynamic characteristics and seismic response effect of Jiuzhou channel bridge can be ignored by comparing whether it consider the dynamic water or not, and explore the variation rule of seismic response by hydrodynamic force under the different depth. The research results in this paper could be used to provide some useful reference and guidance to bridge designers, construction and management personnel.