Applied Research Of The Combination Elastic Modulus In CFST Arch Design

In this paper, CFST(concrete-filled steel tubular) arch bridge was the studystructure, briefly introduced overview and research development of this combinationstructure; And focused on CFST arch bridge application superiority of development andresearch status, Including the latest achievements of the theory and engineering practice;On the basis of collected large number of existing data of CFST components and CFSTarch bridge of recent year, summary analyzed the creep effect research situation ofCFST numbers in the recent years, including different computing forms of combinationelasticity of CFST members in China and abroad; Through the Creep effect mechanismand impact factors, focused on the analyzed the creep effect theory and methods anddifferent computing models of the creep coefficient that influenced the creep effect;Based on Midas/civil finite element software as calculation and simulation platform,the calculation theory and methods of the CFST arch bridge were introduced, and thentake a CFST arch bridge as the calculation example, explored the appropriate methodsof modeling and building the finite element model; Based on this finite element model,focusing on analyzed the CFST arch bridge load capacity under different creep effectfactors, such as the fitting ways of the main arch rib composite section elasticity of theCFST arch bridge, including stress analysis under transformed section method and theunified modulus method of completed bridge state, as well as internal and externalinfluencing factors to CFST arch bridge creep effect such as concrete strength, loadingage and environment relative humidity; In addition, this paper focused on analysis thecreep effect of CFST bridge under considering of construction stages, including perioddividing of construction stages and creep analysis. In addition, this paper also focusedanalysis of the effect of creep under taking into account the impact of the constructionphase, including of stress and deformation conditions of concrete filled steel tube archbridge in whether to consider the creep effect, as well as under different creep age in theforce.Under the guidance of above ideas, some constructive conclusions of the CFSTarch bridge creep effect were got: Stress and deformation calculation result betweentransformed section method and unified modulus method showed a similar trend, twoanalog of main arch cross-section did not significantly changed the form of internalforce distribution and maximum force sectional position along arch direction; And thetranslation section method calculations showed smaller calculated value, the result safe side; In comparison, the deformation was smaller sensitive to the two differentsimulation methods, deformation graph only slightly significant separated at the dome.To the stress and deformation under considering creep of different timeliness canbe found: Grown over time, creep impact still increased while stress and deformation nolonger obvious from1year to10years which illustrated the creep basically completedwithin one year after the opening of the arch bridge construction; Creep effect of CFSTarch bridge was mainly manifested on stress redistribution: In the same cross-section,creep made steel pipe stress increased while the core concrete stress gradually decreased,but did not significantly affect internal force distribution form and position of maximumforce which had important significance to the same type bridge.