Study On The Sensitive Factors And Key Technologies In The Construction Process Of Continuous Beam Bridge

Since the reform and opening up 40 years ago,China’s bridge industry has made remarkable achievements.The continuous steel structure bridge is widely used in the plain and hilly area because of its linear beauty,good integrity and short construction period.With the deepening of bridge design theory and the maturity of construction method,the bridge span is also developing to the direction of large span.During the cantilever construction process,the construction section is increased,the construction is difficult,and the system transformation is complex,which leads to the increase of the linear and structural stress of the bridge under the influence of uncertain factors during the construction process,and then affects the strength,rigidity and stability of the continuous steel structure bridge Sex.Therefore,the research on the potential influencing factors and key technical problems in the construction process of long-span continuous steel bridge is of great practical significance.Based on a three span continuous steel bridge of 65 m + 110 m + 65 m,this paper studies the key technical problems in the construction process.The specific research contents are as follows:1)Based on the literature review at home and abroad,this paper introduces the development of the continuous steel structure bridge,analyzes the main problems existing in the construction control of the continuous steel structure bridge,and summarizes the research status and research ideas of the construction control of the continuous steel structure bridge.The sensitivity analysis of structural design parameters of continuous steel structure bridge is carried out by using control variable method,and the parameters that have great influence on the main beam structure,high sensitivity and less influence and low sensitivity are studied,so as to focus on the control in the later construction process.(2)Using the bridge calculation and analysis software MIDAS civil2017,taking Xihe super large bridge of Hefei Fuzhou high speed railway as the engineering background,the finite element model of 65 m + 110 m + 65 m three span continuous steel frame bridge is established for construction simulation analysis.This paper studies the sensitivity of the main factors affecting the deflection of the prestressed concrete continuous steel structure bridge,such as the concrete elastic modulus,the concrete bulk density and the prestressed tension control stress,so as to provide the theoretical basis for the linear control in the construction process;analyzes the deflection and internal force of the beam in the key construction steps,and analyzes the influence of the prestressed tension on the linear of the beam in the cantilever pouring construction.(3)In view of the large pouring volume in the construction process of No.0 block,which may be caused by the temperature cracks of hydration heat stress,the finite element software MIDAS / fea2017 is used to model and analyze the No.0 block,discuss the influence of different convection coefficient on the temperature stress of concrete,propose reasonable temperature control measures,and guide the construction with the research results.(4)Combined with the general situation of continuous steel structure bridge project,this paper systematically expounds the common closure sequence of continuous steel structure bridge,uses the finite element software MIDAS / civil2017 to analyze the linear and mechanical influence of closure sequence in different temperature difference situations,understands its change trend,and draws relevant conclusions;according to the closure scheme given in the analysis,through theoretical calculation and software to simulate the stress situation of closure framework,and relevant analysis The method provides convenience for the same type of site construction.