Construction Control And Analysis Of Long-span High Speed Railway Beam-arch Composite Bridge

Long-span continuous beam-arch composite bridge has been widely used in bridge engineering in recent years due to its novel structure and good mechanical performance.At the same time,the construction control consciousness and standard of long-span continuous beam-arch composite bridge have also been emphasized and improved.On the basis of summarizing the development of continuous beam and arch composite bridge at home and abroad,this paper summarizes the construction control of continuous beam and arch composite bridge,and makes a comprehensive analysis and research on the monitoring and control methods of a(90+180+90)m long-span high-speed railway girder and arch composite bridge.This paper mainly studies from the following aspects:(1)The continuous beam arch bridge was established by applying the Midas/Civil finite element model of the complete bridge each construction stage is obtained by calculation and analysis of displacement and stress data,provides the theoretical data for construction control,control of site construction has important guiding significance.(2)The method of rigid support and the method of rigid suspender are used to determine the bridge's reasonable state of bridge formation.By comparing the stress of continuous beam and arch rib under the two kinds of bridge formation states,it can be seen that the method of rigid support is more suitable for the determination of the bridge's reasonable state of cable force.Using the method of iteration of reverse-normal difference and the method of influence matrix,the cable forces of the boom under different construction sequences of primary tensioning and secondary tensioning are obtained.By comparing and analyzing the stress and displacement of the arch rib under each construction scheme,the optimal tensioning scheme is determined by twice tensioning and adopting symmetrical interval tensioning from the arch foot to the vault top.(3)Midas/Fea was used to establish the finite element model of the bridge arch joint,and the stress and displacement data of continuous beam,arch abutment and arch ribbed concrete and arch ribbed steel tube under the action of the equivalent load bureau were obtained.Through the data analysis,it can be seen that the stress of the joint of the beam arch is reasonable in the construction stage,and the deformation meets the design requirements(4)For the large span Gao Tieliang-continuous beam arch combination bridge completed,stress of the arch rib and linear,and the boom of on-site monitoring,through the contrast analysis of measured values and the theoretical value,the stress of the continuous beam and arch rib section measured values conform to the theoretical value and the whole bridge elevation each segment after tensioning and derrick tension of continuous beam after the measured maximum difference level and theoretical level is less than 15 mm,deformation of the arch rib measured values conform to the basic theory of value change,according to the optimal tension solution of tension after the boom into a completed bridge and the design value difference less than 4%,continuous beam and arch rib in the construction process of the linear and stress have showed good good development trend,The derrick cable force conforms to the requirements of relevant specifications.