Study On Cable Adjustment Of Cable-stayed Bridge With Curved Tower Mixed Beam By Unstressed Cable Length Method

Modern traffic engineering has put forward higher requirements for the artistic modeling and span of cable-stayed bridges.The shape of cable-stayed bridges is becoming more and more personalized,and the span of cable-stayed bridges is becoming larger and larger.This puts forward higher requirements for the construction method and construction control technology of cable-stayed bridge.Engineers have been looking for more concise,efficient,safe and accurate construction methods to promote the development of construction technology and the improvement of construction control theory.Long span cable-stayed bridge has long girder length,high main tower and large number of stay cables,because of its large scale,it is not convenient to form at one time.So at present,bridges with large span such as cable-stayed bridges basically adopt the method of phased installation in the process of construction.Monitoring and feedback correction of the bridge construction process are carried out by construction contro l to ensure that the internal force of the structure and the linear design requirements after the completion of the construction are ensured.The main purpose of this paper is to find out the feasibility and reliability of cable-stayed bridge with curved tower hybrid beam.The main research method is to establish MIDAS finite element model for correlation analysis.The key contents and main results of this paper are as follows:(1)This paper introduces the stress-free state method and discusses the operation process and points for attention of using MIDAS/Civil indirectly to realize the stress-free state method.(2)Based on the Huaihua Yazuiyan bridge,a bridge model is established to determine the reasonable bridge status of the bridge,and the reasonable cable force,the line shape and the key section stress of the main beam,the deflection of the main tower and the critical section stress are obtained.(3)Based on the model of once completed bridge of Yazuyan Bridge in Huaihua City,the reverse disassembly calculation of the bridge is carried out,and the reference initial tensile force is obtained in the course of calculation.The initial tensioning force and the secondary cable force satisfying the reasonable state of the bridge are determined by the method of repeated cyclic calculation of the inverted disassembly and the formal assembly.(4)The model of the non stress state method of the Yazuiyan bridge is established in MIDAS/Civil,and the construction process is calculated using the length of the cable suspension catenary based on the EXCEL iteration to calculate the exact length of the non stress.(5)The feasibility and reliability of the stress free control method are verified by comparing the analysis results of the inversion and assembly iteration method with the stress free control method,and the advantages of using the method are summarized.(6)The stress free control method is used in the construction of cable-stayed bridge with curved tower and the sensitive parameters are analyzed.The key to this method is to calculate the exact length of the cable in the process of construction.