Research On Construction Control Technology For Continuous Beam Of(40+2×65+40)m Pipeline Bridge

With the rapid development of traffic construction in China,prestressed concrete beams with many advantages have been booming.The prestressed concrete continuous beam constructed by cantilever pouring method will experience a series of complex changes in the construction process,and the stress state and line shape of the main beam will become quite complex.In order to ensure the safety in the construction process and meet the operation requirements,it is necessary to control the construction of each stage in the cantilever construction process of the continuous beam,so as to meet the design of the prestressed concrete bridge requirement.The object of this paper is the prestressed concrete continuous beam pipeline bridge,which belongs to the water conservancy bridge.There are only three water pipelines on the bridge,and there is no traffic requirements.At present,the construction control technology of prestressed concrete continuous beam in China has been relatively mature,but there are few construction control cases involving prestressed concrete continuous beam pipeline bridge.Taking the(40+2×65+40)m continuous beam pipeline bridge as the engineering background,this paper studies the bridge construction control technology,and mainly completes the following work:1.Firstly,the principle of continuous beam construction control and the main influencing factors of construction control are introduced,then the finite element model is established according to the design drawings and the actual parameters of the site,and the simulation calculation and analysis are carried out.2.Considering the transformation of continuous beam structure system,three closure schemes are analyzed.By comparing the maximum stress,displacement and stress,the three closure schemes have no significant difference.3.The elastic modulus of concrete is an important structural parameter.This paper mainly introduces the relatively advanced elastic modulus measurement means at present.It is more efficient and direct to measure the elastic modulus with the elastic wave method,and the data acquisition is more comprehensive and representative.4.Monitor the line shape and stress in the whole process of construction,compare the measured actual parameters with the model analysis results,and adjust the actual parameters in consideration of concrete self weight,elastic modulus,shrinkage and creep,so as to provide theoretical basis for construction control in each stage of cantilever construction.5.Through the combination of theoretical analysis and on-site construction control of the beam,the alignment and internal force of each stage of the bridge construction process meet the design requirements,and finally the bridge is closed smoothly.