Research On Linear Monitoring Of Large Span Railway Continuous Beam

With the rapid development of China’s railway transportation, the large span continuous beam has many advantages, such as large span and driving smoothly, it has become the preferential choice of the large span pre-stressed concrete girder bridge, and its main construction method is cantilever construction method. The construction process of the railway continuous beam is extremely complex. The application of the cantilever construction method will inevitably lead to the change of continuous beam structure and its complex internal forces and displacements. In order to guarantee the safety of the railway continuous beam’s structure, and ensure the fold smoothly, the linear and the internal force meet the design requirements. It is particularly critical of the effective linear monitoring of each quarter.In this paper, we take the cantilever construction of the YiChun super-large bridge across the MingYue road continuous beam as the background, and study the linear monitoring process of each segment and the beam linear, the stress variation of the bridge. In addition, we study the monitoring technology of the large span pre-stressed concrete railway bridge continuous beam combined with the railway traffic characteristics, based on the summary and analysis of domestic and international and the development of monitoring technology. There are two aspects of the linear monitoring of the railway bridge continuous beam, they are both equally important, it must be monitored so fully that could meet the design requirements ultimately.In this thesis, we analyze and comparative the method of linear monitoring combined with the linear monitoring of the YiChun super-large bridge across the MingYue road continuous beam, and according to the characteristic of railway bridge continuous cantilever beam. We choose the adaptive optimal to control the beam. Combined with the feature of bridge designing and construction, by using the finite element analysis method to analyze the section of the segments, we give the internal force and deformation of the section, and analyze the error according to the construction process monitoring results, then adjust the next segment vertical mold elevation. The results of the research apply directly to the beam linear monitoring.Many factors which influence the actual condition not match the theory condition, this paper analyze the sensitivity of beam alignment parameters. Through the close of the largest section of the cantilever section and calculated the impact of beam parameters are linear pre-stressed, concrete bulk density and elastic modulus, creep and long-term effects. Cantilever segment of the railway continuous beam poured section appear serious errors, it is almost hard to eliminate, therefore, the prediction of the next section is extremely important. This paper describes detailed the gray system control theory which can be used for the structure state estimation and prediction, and apply to linear monitoring. The results show the feasibility of the structure state prediction of the gray system control theory.