Analysis On Construction Control Of High Pier Long-span Continuous Rigid Frame Bridge

As the wide use of long-span continuous bridge,the continuous rigid frame bridge construction control theory became more mature and perfect,especially the research on the design parameter identification and correction method,greatly improved the precision of the construction control.This paper is based on the engineering background of the Dadu River Bridge and combined with the characteristics of cantilever construction of continuous rigid frame bridge.In order to get the more accurate control,this article simulates the whole process of the bridge construction with the finite element software Midas/civil and identify design parameters with the neural network method.The main contents of this paper are as follows:Firstly,the continuous rigid frame bridge is briefly summarized,including its basic characteristics,development status and trends and construction methods;Secondly,it comprehensively introduces the theories of the continuous rigid frame bridge construction control,including its steps,content,calculation and analysis methods,the main impact factors and parameter identification methods,etc.Thirdly,it establishes the finite element simulation model of the Dadu River Bridge,analyzes the sensitivity of the design parameters impacting the construction control results.The method determining the main and secondary design parameters which affect the construction control results is through comparing the corresponding beam deformation and stress variation amplitude under the condition of all the design parameters for the same changes.Fourth,in order to realize the rational control in the stress,linearity and temperature of each section of the bridge and ensure the Dadu River bridge construction control to satisfy the requirements of the specification,it was through comparing and analyzing the calculated data by the theoretical model simulation and the actual measured data according to the characteristics of cantilever construction.Fifth,the parameter identification of the Dadu River bridge construction control applies BP neural network to judge the feasibility of the method on the construction control of the great span bridge,which by analyzing the size of the error between the measurement data of deformation of main beam and the forecast data calculated after the main parameter identification.The idea of this paper is based on the bridge construction control adaptive control method,and gradually expands the construction control process of Dadu River bridge.Firstly,it establishes the Structure Calculation System,and obtains the bridge pre-crown by calculating each girder segment deflection of the cantilever construction.Secondly,it is through the structure of the Test System to obtain the real-time stress,deflection and temperature monitor data;Thirdly,the Error Analysis System is what used to achieve the identification and judgment of parameters affecting construction control;Finally the Forecast System is used to refine design parameters and gets the subsequent segment formwork erection elevation by refined design parameters.