Simulation Of Construction And Study On Optimization Of Cable Force For Extradosed Cable-stayed Bridge

As a new kind of bridge structure system,extradosed cable-stayed bridges has been used more and more in engineering practice because of its superior structural performance,good economic efficiency and good appearance.As the structure of the cable,the pylon and the girder,reasonable bridging cable force is an important prerequisite to ensure the mechanical performance and structural safety of the bridges.Therefore,the optimization of cable force under dead load of extradosed cable-stayed bridges has become an important and difficult design aspects.With the increase of bridge span,the balanced cantilever construction with traveling forms has become the mainstream method of prestressed concrete bridges.The analysis of the construction phase for the bridge,the significance is not only to ensure that the bridge state to meet the design expectations,but also to ensure the safety of the structure during construction phase.The analysis of the setting cable tension of the extradosed cable-stayed bridges is an important but difficult point in the construction analysis.In this paper,the study is based on the main bridge of Yuxi River.Firstly,the methods of optimization of cable force for extradosed cable-stayed bridges are summarized,and a brief review is made.Secondly,with the sum of the bending strain energy and the tensile and compressive strain energy as the objective function,the influence impact matrix method and the MATLAB quadratic programming module are used to optimize the cable force of the extradosed cable-stayed bridges under dead load.Then,ANSYS analysis is used to optimize the cable force of the extradosed cable-stayed bridges.Then,based on ANSYS optimization analysis,the cable force results are taken as the cable force of finished bridge.Based on Midas Civil software,the initial tension force is obtained by fitting the iteration method and the stress state of the girder in the construction stage is verified.Also,calculation method of camber is given.Finally,the influence of tower-span ratio on the structural system of extradosed cable-stayed bridge is studied.Increasing the tower-span ratio can effectively improve the structural force performance.The results show that the two methods are reasonable and effective.It can guide the optimization of cable force under dead load of finished bridges for the same type bridges.But will increase the economic cost and cause the cable to increase the stress.