Analysis Of Seismic Response On Urban Railway Isolated Bridge

Earthquakes are one of the most destructive natural disasters in daily life,therewere many cases occurred that bridges collapsed under earthquake force,so theanti-seismic design of bridges must be strictly enforced,isolation technologydeveloped fast in recent years,setting isolators between the columns and the upperstructure of the bridge is the most common seismic isolation technology,isolator canextend the basic vibration period of a bridge,to aviod concentration of seismicengergy range.to reduce the seismic force of a bridge.Isolators can also use their ownmaterial characteristics to dissipate the seismic input energy of a bridge to ensure thesafety of the main structure of the bridge.Therefore the research on isolator is verynecessary.In this paper,by using dynamic analysis and the principle of energy,usingsoftware Ansys to establish the analysis model of three different bridges,focusing onthe impact on the seismic isolatior of the bridge, the main content is organized asfollows:1. Make a summary about the type and the phenomena of the damage of thebridge,we can get some apocalypses from them,then introduce some new anti-seismictechnology,especially the seismic reduction and isolation technology.2. Describes the derivation and calculation methods of dynamic analysisNewmark-β method formula,and describes the development process and the basicprinciples of energy,derive the basic equations of single degree of freedom andmulti-degree of freedom on the principle of energy.Make a detail description of thesignificance of the energy of each part of the energy equation represented.3. Using Ansys software to establish the analysis model of three different bridgesand make dynamic analysis of them.By using the principle of energy method,setdifferent parameter optimized conditions for the initial damping steel bearingparameter and input different seismic waves, to calculate the seismic input energyunder different isolator parameters of the same bridge.find out which parametercauses the least seismic input energy.that’s what we actually need.4. Set the parameter which is decided as the damping steel bearing parameterapplied on the three bridge.then make dynamic analysis of the three bridge wheredamping steel bearing is not applied.Extract the typical response of the the same location of the three bridge, By making a comparison on response between the bridgewhich has the damping steel bearings and with the bridge which has no damping steelbearings.then calculate the reduce rate of response that the damping steel bearingsdeclined.By making that comparison,we can find out the influence that the dampingsteel bearing can do to the bridge.5. Describes the reason why effects of the travelling wave generates and twodifferent ways on the seismic wave input.By calculating and analyzing the result ofthe response,to find out the different and the same between the two methods on theanti-seismic calculation of the long span continuous beam bridge.Finally, set differentinput time of seismis waves to the long span continuous beam bridge to simulate theeffects of the travelling wave.Extract the response of the typical position.make acomparison between them to analyze the influence that the effects of the travellingwave can do to the long span continuous beam.