Research On Key Technology Of Construction Control Of Pingnan Third Bridge

Large-span concrete-filled steel tube arch bridges generally use the cable-hoisting method of cable-stayed buckle.The construction control is divided into two phases:the empty steel tube arching phase;the bridge phase.After the empty steel pipe is arched,the adjustment of the arch rib shape and internal force is small,and there are not many adjustment methods.Therefore,the cable force of the stay cable and the arch truss shape are the key to construction control.In this paper,the Pingnan Third Bridge is taken as an engineering example,and Midas is used to establish a finite element model to simulate the arch rib lifting process,calculate the cable force of the cable staying process and optimize the cable force,analyze the linear changes of the arch ribs,and propose optimization.Linear method.The research on the concrete pouring sequence in the pipe is also carried out.The specific research work is as follows:(1)This article summarizes the history of the development of CFST arch bridge,the common construction methods of CFST arch bridge in construction,and uses the Pingnan Third Bridge as the engineering background to introduce the significance of construction control,the principles and methods of construction control,and the calculation of construction control.Content and error analysis and feedback in construction control.(2)Taking the Pingnan Third Bridge as the engineering background,the article puts forward the optimization of the cable force calculation.The finite element method is used to calculate the cable force and the control displacement of the lifting stage.The influence of temperature changes on the elevation is analyzed,and the influence of temperature on the linearity during the lifting stage is proposed.Based on the ideas and methods,the influence of temperature on the control displacement was calculated using finite element method.(3)Based on the Pingnan Third Bridge,the article calculated and determined the initial tension of the load-carrying cable and cable.The maximum deflections of arch tops in different perfusion sequences,the stress of a steel tube under a single suspension,the initial stresses of the steel tube at the arch foot after completion of the perfusion,and the comparison of the effects of cables and cables on the flexural cables on the arch are analyzed and calculated.Finally,the optimal perfusion scheme was determined through analysis.