Construction Control Calculation And Stability Analysis Of Cable-stayed Steel Box Arch Bridge

Cable-stayed hanger-cable hoisting method is a commonly used construction method for long-span steel box arch bridges.Due to geographical factors,the asymmetrical arrangement of the buckle cables in the cable-stayed hanger system causes the arch ribs to experience large unbalanced forces before closing,Making the linear control and stability problems of the steel box arch bridge particularly prominent during construction.Therefore,this paper takes the Anhui Xin’anjiang Bridge as the research object.The bridge is constructed with an asymmetric cable-stayed hanger system.In order to ensure its construction safety and reliable quality,it conducts related research on its construction control calculation and stability.The main research contents are as follows :(1)Introduce the construction control and calculation theory,including: the necessity,content and method of construction control,the calculation theory of reasonable bridge state,the calculation theory of reasonable construction state,and the calculation theory of cable force of cable stays.Provide a theoretical basis for the subsequent construction control calculation.(2)The Midas Civil calculation model of the steel box arch bridge is established.The rigid support method and the bending energy method are used to solve the bridge hanger force.The advantages and disadvantages of the two methods are compared and analyzed,and the reasonable bridge hanger is determined.force.Aiming at the construction of the boom,the concept of one-time tension was proposed,and the tension of the construction boom was solved by the disassembly method and the unclosed combining force method,and the applicability of the unclosed combining force method to solve the tension of the boom construction was verified.(3)The Midas Civil calculation model of the steel box arch rib diagonal pull buckle is established.The unknown load factor method and the elastic-rigid support method are used to calculate the asymmetrically arranged buckle cable force,so that the arch rib is being removed The arched line shape after buckling meets the target line shape.(4)On the basis of the hanger force and buckle cable force solved in the previous chapter,the Midas Civil construction calculation model of the whole process of thelong-span steel box arch bridge was established,the structural mechanical properties of key construction stages were analyzed,and the calculation of the bridge was verified There is a difference between the state and the theoretical state,and the sensitivity analysis of parameters such as elastic modulus,bulk density and ambient temperature is carried out.(5)The geometrically nonlinear stability analysis of the linear elasticity and the initial defects was carried out during the construction and completion of the steel box arch bridge.Finally,the stability of the arch ribs,the weight of the deck and the number of cross braces for structural stability were discussed.Law of influence.