Study On The Influence On The Seismic Catastrophe Performance Of The Cable-stayed Bridge Construction Process

Earthquake struck home and aboard frequently in recent years.Since 2012,earthquake above level M8.0 happened 8 times.As a hub of communication,the damage of bridge in earthquake can result in huge losses in life and economy.If we could have a full understanding of bridge's anti-quake capacity when designing,and make sure that it can still work after small earthquake,can be repaired after normal one,and can hold still after big,the losses can be reduced.However,most researches are focused on the anti-quake capacity of a bridge piper,few people cares about the influence of construction process on anti-quake capacity.To improve this shortage,we will build a overall mode of a cable-stayed bridge by Midas Civil software,simulate the whole process of construction,analyze the anti-quake capacity of tower bottom and girder by IDA method if the construction process(the order of the cable adjustment and closure)was changed.Also,we made some great conclusions by comparing the anti-quake capacity in different construction phase of cable-stayed bridge,which may be an reference for construction and its design experts making some decisions on construction process.Detail contents is as followed:(1)The article systematically introduced the basic principles of three analysis methods of earthquake response,its characteristics and sphere of application.Besides,we made detail exposition on the structural characteristics and construction force characteristics of cable-stayed bridge and IDA method,which made a theoretical foundation for further research.(2)With the practical engineering background,the article exhaustively introduced the construction method of cable-stayed bridge's cable tower and girder,and the simulation process of construction period by software.Based on these two different construction process,one that we change the cable adjustment order(firstly adjust the front cable or end cable)and the another that we change the closure order(firstly fold side span closure,and then middle or transform order),we established different Midas Civil models and analysis the structural dynamic characteristics.(3)setting structural parameters---bending moment?the corner?shear force,and the shearing drift,analyze the results of nonlinear time history,and draw IDA curves of the girder when vertical earthquake happens,and IDA curves of the tower bottom when longitudinal and transverse earthquake happens.(4)According to the differences of IDA curves under different construction process.We found the the different anti-quake standards to evaluate the influence of construction process on cable-stayed bridge.This influence is mainly manifested by the girder,which means firstly adjusting the end cable is helpful to improve the girder's anti-quake capacity,while changing the closure order has little influence on cable-stayed bridge's anti-quake capacity.