Backward Analysis Based On State Update Of Construction Control Of Cable Stayed Bridge

In recent years,the construction control of cable-stayed bridges has become a hot research topic in the field of bridge at home and abroad,as a result,many study results are obtained nowadays.Based on the learning from the former studies and summary of those study results,this thesis focuses on the highways and the small-and-medium span steel cable-stayed bridge in cities.The analysis of those subjects is combined with practical data collected through the experience of monitoring the construction of Yuhe Bridge in the North Ring Road in Datong,Shanxi province.The paper emphasizes the ability of cable-stayed bridge itself of adapting to the construction control system and proposes the backward analysis method which is according to the update of mode.This thesis is mainly divided into the following three parts.The first part is about the design of cable-stayed bridges.The aim of this part is to analysize and summarize the structural characteristics of the North Ring Bridge,and determine the reasonable construction state of the bridges according to the reasonable status of built bridges and the construction sequence.For a steel cable-stayed bridge with a falling off construction method,the backward analysis method is used to determine the reasonable construction state.The concept is clear,simple,efficient and practical.The second part focuses on the parameter identification and updating module of finite element.Based on the sensitivity analysis of parameter,this part uses the least squares method and measured data to identify sensitive parameters in terms of the settlement of main girder of the North Ring Bridge before its cable tension.The results of upgrading module of finite element are also verified so that the necessity of correction parameter identification in construction process and the finite element model are explained.For the process of cable tension,the stiffness of the temporary support of the main beam has a great influence on the cable force changes.According to the matrix principle,the problem of the identification of the stiffness of the supports is converted into the influence on correction of matrix in the construction process.The third part is about the optimal quantity of adjustment to calculate module.The error of cable force adjustment is shifted to the calculation of the extreme value of constrained multivariate function.In that sense,the correction effect and applicability of two kinds of optimization methods are studied according to the examples of cable-stayed structures.This part gives the calculation sequence of adaptive control theory in the cable tension process of the North Ring Bridge and calculates the optimal adjustment amount by taking four examples in the first round of the North Ring Bridge cable tension.The contrast and analysis of the cable force error correction of the actual bridges show the necessity of correcting the error.