Seismic Performance Of Super Long Span Continuous Rigid Frame Bridge With Corrugated Steel Webs

Long span continuous rigid frame bridge with corrugated steel webs(CRFBWCSW)is widely in western China,because of its strong spanning capacity,good force performance,fast and convenient construction,and many other advantages.The static performance of long span CRFBWCSW has been studied much systematically,but there are few studies on the dynamic performance of long span CRFBWCSW,especially the seismic performance,evaluation and optimization of failure modes,and seismic reduction methods and effects of long span CRFBWCSW in complex geological conditions.In this paper,a series of systematic researches have been conducted in conjunction with a super long span CRFBWCSW,which is under construction.In this research paper,we have done the following works:Firstly,numerical model of the pile-cavity joint action system is established by ABAQUS software.Dynamic response of pile bottom displacements,stresses,strains and bending moments for a single rectangular and elliptical cavity under the effect of ground motion after inversion has been analyzed.Then,the seismic performance influencing factors of the super long span CRFBWCSW pile-cavity,such as pile diameter,cavity size,pile top load,rock cohesion and peak ground motion on the safe thickness of cavity top slab and vertical displacement of pile bottom has been studied.The multiple linear regression analysis has adopted to obtain the multiple regression model for the safety thickness and vertical displacement of pile bottom.And then,the multiple regression model is optimized.Finally,the seismic performance of single cave and beaded pile foundation-cave are compared.Secondly,theoretical,experimental and numerical simulations were carried out to analyze the force performance of corrugated steel webs with stiffening ribs.Three specimens of corrugated steel webs with different stiffening rib arrangements were designed,namely,pure corrugated steel webs,corrugated steel webs with vertical stiffening ribs and corrugated steel webs with one transverse stiffening rib,based on the basic stress characteristics of corrugated steel webs in the negative moment zone near the piers of rigid bridges.The buckling modes,shear strength,stiffness and strain distributions of each specimens were obtained.Then the theoretical,experimental and numerical simulation results were compared and analyzed.Then the detailed parameter analysis,theoretical calculation and finite element analysis for the actual bridge web stiffener scheme are carried out,which provides suggestions and verification for the use of a suitable form of stiffener in the design of corrugated steel web girder.Thirdly,The performance objectives of this bridge are given by analyzing the performance objectives of well-known bridge structures across the world,taking into account the structural peculiarities of super long span CRFBWCSW.The seismic performance of the bridge under longitudinal earthquakes is evaluated based on the seismic time-temporal acceleration curves synthesized from the design response spectrum in the seismic design code for highway Bridges.Then,the results of ETM are compared with the results of IDA analysis method under the action of 16 ground motions in the far field and 16 in the near field to verify the accuracy and reliability of the seismic performance results of the ETM for calculating the seismic performance of the super long span CRFBWCSW.Fourthly,the failure modes of the super long span CRFBWCSW under the far-field and near-field ground motions are analyzed using the weighted rank sum ratio method.When considering pile-cavity failure,the failure modes of the bridge was also analyzed.Then,the weakest failure mode of the bridge is identified.and a design for optimizing the failure modes of a very large span waveform steel web continuous rigid frame bridge is proposed by combining the failure paths of each element of the bridge.A design method to optimize the failure mode of the super long span CRFBWCSW is proposed by combining the failure path of each element of the bridge.At last,a replaceable energy dissipation tied beam device is proposed according to the characteristics of the dependence project bridge structure,which constitutes a replaceable fuse energy dissipation system for the super long span CRFBWCSW.The effect of the tied beam on the seismic reduction effect and failure mode of the super long span CRFBWCSW is studied,and the design process of the replaceable energy dissipation tied beam is proposed to optimize the seismic performance of the bridge.