Seismic Behaviors Analysis Of Concrete-filled Thin-walled Square Steel Box Piers Based On OpenSees

As a new kind of combination design form in composite structure, concrete-filled thin-walled steelbox pier is composed of inner and outer steel box, core concrete as well as stiffening ribs. This kind ofpiers show great economic and technological advantages such as superior seismic performance,convenient construction, light weight, and low foundation requirements when appling to high pierbridges. This paper introduced the application of this kind of piers inlong span continuous rigid framebridge with high pier, as well as its anti-seismic performance, the main research work is as follows:1) This paper describes the problems currently encountered in traditional reinforced concrete in theapplications of high piers, combining the optimization and development of current pier structure, theauthor proposes the application of thin-walled steel box concrete piers in high piers, meanwhile, thestructure form as well as the current research status at home and abroad of seismic performance ofconcrete piers with steel box are intruduced..2) Taking Sanshui River Bridge as the project background, o the basis of intrinsic reinforcedconcrete piers, applicated to concrete-filled thin-walled steel box piers, and seismic response andeconomy technique analysis of the two kinds of piers have been acquired.The results show that:concrete-filled thin-walled steel box piers havebetter seismic performance and economic andtechnological advantages.3)Collation current computation theoris of concrete-filled steel tube and numerical computingmethods for seismic performance study, the finite element model of concrete-filled rectangular steel tubewere tested and the results was compared with the finite-element pacakage OpenSees, the simulationresult accorded well with the experiment result, the effectiveness and reasibility of the model are verified.4)On the basis of the work above, scaled pier models were established, the skeleton curve changinglaws of hollow and solid concrete-filled thin-walled steel box piers are analyzed in different axial forceratio, length-diameter ratio, hollow ratio, steel ratio, strength gradeof concrete, yield strength of steel, etc.5)Tri-linear hysteretic model of skeleton curve of the hollow concrete-filled thin-walled steel boxpiers are established, analysis of the comparison between theoretical calculation and the simulated resultsof OpenSees, shows that the theoretical calculation is accurate, streamlines complex process of softwareprogramming, as well as save the calculating time, which can be served as a reference for the experimentdesign and analysis afterwards.