A Study On Construction Scheme Optimization And Construction Monitoring Of Concrete Filled Steel Tubular Arch Bridges

As a traditional type of bridge which has the history of1800years, arch bridgehas been developing to this day because it has features both beautiful andload-bearing. Early arch bridge was restricted by its gravity because the material ofconstruction was stone mostly which had dead load. But this limit was not brokendown until concrete-filled steel tubes arch bridge appeared. During the construction,the installed weight of concrete-filled steel tubes arch bridge is lighter than traditionalarch. It has been developing rapidly in recent20years because of its mer its. Withaccumulation of theoretical knowledge and practical experience, our country hasmastered kinds of construction method about concrete-filled steel tubes arch bridgewhich has lead to a problem to choose a construction scheme. Previously scheme wasselected by one or two practical factors which could not get perfect result so peoplestarted to find ways to screen the construction schemes. Bridge constructionmonitoring is really related to that whether the stress is reasonable and the linearstructure can meet design requirements under both under-construction state andcompletion state, and whether the bridge can work well in the operational period.Therefore, based a case study of Laihua Bridge in Laibin City, the thesis, analyzed theoptimization model and Monitoring mechanism of construction of concrete-filledsteel tubes arch bridge by combination of theoretical modeling and empirical analysis,as a reference for similar engineering construction.First, based on the principles of Analytic Hierarchy Process (AHP), this thesisconstructed the Analytic Hierarchy model for construction scheme of concrete-filledsteel tubes arch bridge (CSTAB) with the evaluation index system of cost, projectperiod, technical feasibility, construction conditions and environmental conservation.As a case analysis of Laihua Bridge, we further compared the three keyTSCAB-construction schemes of cable hoisting method, rotation construction methodand cable-stayed cantilever method by the above Analytic Hierarchy model forCSTAB construction scheme. According to the comparing results, we can make aconclusion that cable hoisting method is the most excellent construction scheme forLaihua Bridge Project, consistent with field construction scheme. Through theoreticalcalculation and case analysis, Analytic Hierarchy model for CSTAB constructionscheme is reasonable and reliable. Second, viewing the bridge construction process as a grey process, we used thegrey system theory to construct the prediction model of monitoring bridge structureconstruction process which includes data processing, choice of specific model type,establishment of GM (1,1) model and residual GM (1,1) model, test of model accuracy.As a case analysis of Laihua Bridge, we carried out the simulation analysis of stressand linear monitoring data at the each stage of Laihua Bridge construction process byprediction model of monitoring bridge structure construction process. Furthermore,the conclusions were applied to the construction of Laihua Bridge project.Finally, based on the optimization model and monitoring mechanism ofconstruction of concrete-filled steel tubes arch bridge by combination of theoreticalmodeling and empirical analysis，the thesis summarizes the relative conclusions andput forward the implications for similar engineering projects. Meanwhile, we broughtobjectively out the shortcomings of this thesis and put forward some relative researchdirections in future.