Research On Dynamic Performance Of Composite Trough Girder With Corrugated Steel Webs

During the booming era of urban transportation and intercity high speed rail projects,parts of the traditional structural forms can no longer meet the needs of efficient design,rapid construction,and ever-increasing serviceability.The trough girder with corrugated steel webs(TGCW)is an innovative steel-concrete composite bridge form consisting of a concrete bottom slab,two corrugated steel webs(CSWs),and a pair of concrete top flanges.As a new type of urban rail transit carrier,TGCW combines the merits of both the trough girder and CSWs and possesses the advantages of lower building height,more beautiful shapes,less influence from shrinkage,creep,and temperature gradient,higher efficiency of prestressing exertion,and so on.To the best of the authors’ knowledge,previous studies were limited to the statistical behaviors of TGCW,thus,this thesis will explore its dynamic characteristics and dynamic response under urban rail transit.The main research contents are as follows:1).The research situation of dynamic characteristics and dynamic response under urban rail transit of trough girders and corrugated steel web PC composite bridges,as well as the development and characteristics of train-track-bridge coupling model are summarized.2).Based on Hamilton theory and energy variation principle,the governing equations of motion and natural boundary conditions of single-span simply supported TGCW are derived,and the corresponding natural frequencies and modal shapes are obtained.For verification purposes,the theoretical results are then compared with the finite element analysis results conducted by ABAQUS and the laboratory measured values.The differences in the fundamental frequencies calculated through different theoretical methods are then discussed.In addition,sensitivity studies have been conducted to investigate the effect of span length,bottom flange width,CSWs waveform,and thickness based on finite element analysis.3).Establishes the rigid-flexible coupling model of train-track-bridge system through multibody dynamics software and finite element software,and illustrates the simulation implementation process of the train-track-bridge coupling method through the standard example.By comparing the dynamic response results of the rail mid-span and the track slab mid-span with the standard example,the correctness of the model established in this paper is proved.4).Based on the train-track-bridge coupling analysis,the deflection,acceleration and dynamic amplification factor of the bridge observation point when the B-type metro car acts on the TGCW are observed.Based on the coupling analysis results,the influence of vehicle speed,vehicle weight and TGCW structural parameters on the dynamic response of the bridge are analyzed.5).The dynamic coefficient is not only a function of the bridge span,it is also affected by vehicle speed,bridge structural parameters,etc.The dynamic coefficient obtained by the train-track-bridge coupling analysis are compared with the one obtained by the recommended formula in specification horizontally,and the applicability of the recommended formula in specification is discussed.