Research On Seismic Conceptual Design Of Extradosed Cable-stayed Bridge In Yingkou Minsheng Road

The seismic design of bridges includes two aspects: one is the specific parameters design which focuses on the calculation and analysis and the other is a seismic conceptual design which is the workers' understanding and summary for damage of the earthquake.The second method is that in the early stage o f seismic design,to make rational analysis and judgment then apply it to further detailed design work.The current code for seismic design of bridges in China has pointed out that the concept of seismic design should be paid attention to in the design work.The correct choice of the bridge system is a prerequisite for the success of the seismic conceptual design.The research direction of this paper is the influence of bridge system selection on seismic performance in conceptual design stage.Extradosed cable-stayed bridge is a new bridge appeared in recent thirty years.The seismic performance of the low-tower cable-stayed bridge is not exactly the same as that of the beam bridge or the cable-stayed bridge and there is no regular summary of the seismic performance of the bridge at the same time,therefore,it is urgent to study the seismic performance of the low-tower cable-stayed bridge.This paper mainly relies on the actual engineering and focuses on the structure of the seismic performance analysis of the low-tower cable-stayed bridge under different constraints.This paper discusses the system selection of conceptual design,and provides reference for similar bridge structure design.In the choice of calculation method,this paper uses nonlinear time hi story analysis method.In the study of earthquake resistance,through the summing up and study of the previous earthquakes,static analysis theory,response spectrum theory and dynamic theory are developed in turn.Nonlinear time history analysis as a mainstream dynamic analysis method,which not only can calculate the response within the elastic range of the structural line,but also consider the nonlinear effect.Therefore,it is preferable to use it as the main analytical method.In the concrete work,this paper carries on the simulation calculation to a low tower cable-stayed bridge-Yingkou Minsheng Road Railway bridge.Based on the nonlinear time history analysis method,the response results of the low pylon cable stayed bridge under the condition of two different restraint systems and the action of El-centro seismic wave are analyzed and summarized.By comparing the livelihood of Luqiao in different periods,under the constraints of the system of key parts of displacement,internal force characteristi cs of site seismic response value,the earthquake seismic performance is obviously better than that of the pier tower girder pier beam consolidation system separation,which verifies the the importance of correct choice of bridge system to improve the seis mic performance of the bridge,and it is the key to the success of conceptual design.