Optimization Of Cable Force Of Prestressed Concrete Cable-stayed Bridge And Stability Analysis Of The Construction Process

Cable-stayed bridges have been widely used in more than half a century due to their excellent mechanical performance,reasonable structural characteristics,beautiful appearance and economical cost.They have become one of the most competitive bridge types with large spans..The vigorous development of cable-stayed bridges also puts forward higher requirements and challenges for the design and construction of cable-stayed bridges.With the increase of its span,the optimization of the internal force of the cable-stayed bridge structure and the stability of the construction period become more and more important.The optimization of the internal force of the structure is mainly based on the adjustment of the cable force in the reasonable state of the bridge and the reasonable control of the cable force in the construction phase.This article first introduces the development and prospects of cable-stayed bridges by consulting relevant documents at home and abroad,summarizes the cable-stayed bridge cable force calculation theory and method,and pave the theoretical basis for cable-stayed bridge cable force optimization.The cable-stayed bridge is a high-order statically indeterminate structure.In theory,there are countless kinds of internal force solutions.The reasonable completion state refers to an optimal solution that makes the internal force indicators of the bridge reach a scientific and reasonable optimization.To this end,this paper uses the Qingshui River Bridge as the engineering background,uses the finite element software Midas/Civil2019 to establish a full bridge model,simulates the construction steps of the bridge,and calculates the initial tensile force during the construction phase.The forward installation iterative method is used to determine the initial tensile force of construction.Under the premise of meeting the control accuracy,the cable force can converge well after multiple iterations,without considering the impact of shrinkage and creep,so that the bridge is obtained under the initial tensile force.The cable force is closer to the cable force in a reasonable bridge state.Through calculation,it is found that the various indexes of the bridge control section meet the requirements of the specification,which verifies the correctness of the calculation of the reasonable initial tension by the forward-fit iterative method.On the basis of determining the reasonable bridge status and reasonable construction cable force,the stability of the Qingshui River Bridge during the construction process is studied,the stability analysis of the whole construction process and the typical construction stage is carried out,and the stability of the relevant structural design parameters is studied.Some conclusions have been drawn,which have certain guiding significance for actual projects.