Analysis Of Vehicle-bridge Coupled Local Vibration Response Of Long-Span Corrugated Steel Web Continuous Beam Bridge

As a new type of bridge,the corrugated steel web PC box girder bridge has the advantages of light weight,easy construction and installation,and good seismic performance.The research on it at home and abroad is gradually developing in the direction of large span continuous beams.The research on the static performance of corrugated steel web PC box girder bridges is relatively complete,but the research on the local vibration of vehicle-bridge coupling is relatively small.Improving the design of PC box girder bridges with corrugated steel webs has important theoretical research significance and practical application value.In order to study the local and overall dynamic impact coefficients of corrugated steel web PC box girder bridges under vehicle load,this paper uses ANSYS to establish a corrugated steel web PC box girder bridge plate-solid finite element model to establish a three-dimensional bridge and vehicle structure.The vibration equation is based on the contact relationship between the wheel and the bridge surface,which forms the coupling vibration equation.Use MATLAB software to solve the dynamic equations of the vehicle-bridge coupling system,consider the random excitation of road irregularities,study the displacement vibration response and the mid-span bending moment vibration response of the key research nodes of the bridge;analyze the vehicle speed,road roughness,damping ratio,and number of loaded lane Influence of other parameters on local and overall displacement and bending moment dynamic amplification factor.Change the bridge structure parameters(web type,bearing constraint type,diaphragm spacing,box beam section form)to study the influence of bridge structure design parameters on local and overall displacement dynamic amplification coefficients and bending moment dynamic amplification coefficients.the result shows:The local dynamic amplification factor of the displacement of the box girder is obviously greater than that of the whole main beam.To study the vehicle impact effect of corrugated steel web composite beam bridges,it is also necessary to study the local impact effect;the deck flatness level and bridge damping ratio have an important impact on the dynamic response of corrugated steel web continuous beam bridges;Both the local and overall displacement dynamic amplification factors are greater than the two-car driving conditions.In order to make the partial and overall displacement dynamic amplification coefficients of the corrugated steel web composite beam bridge more safe,it is advisable to use the displacement dynamic amplification coefficient when the bicycle is traveling.Under the guarantee of the same bridge design parameters,the impact of the vehicle on the corrugated steel web composite box girder bridge is smaller than that of the concrete web box girder bridge.Reducing the spacing of the diaphragms,that is,increasing the number of diaphragms,can reduce the local and overall dynamic displacement and dynamic amplification factor of the bridge structure,but when the spacing decreases to a certain value,the structural dynamic response basically remains unchanged,or even increases.Increasing the number of single-box chambers hardly changes the dynamic amplification factor of the structure.Therefore,in the design,for single-box multi-chamber cross-section type corrugated steel web composite beams,the dynamic amplification factor of single-box single-chamber can be approximately used as the consideration of automobiles Design value of shock effect.