Passenger Dedicated Continuous Beam Bridge Construction Control And Temperature Effects

During bridge construction, many determinate and indeterminate factors make the actual state of bridge structure difficult to match the design state. Therefore, the bridge construction control plays the vital role in the bridge construction. Passenger-only lines have the characteristic of the high speed, the ride comfort of the track way and the high demand of the infrastructure construction under the line. Hence, the construction control has more strict demands for passenger dedicated railway bridges.The control of bridge construction is to find and correct problems in time, predicte the elevation of mould plate for next step and eliminate un-stress strain in actual based on structural analysis theories and deviation analysis. At the same time, the final structural stress and alignment of the bridge should meet the design requirements.As the continuous beam bridges on the Ha-Da passenger dedicated railway and Wen-Fu passenger dedicated railway being engineering background in this paper, the alignment prediction and control based on BP neural network and grey theory, the measured strain modification and temperature-effect analysis are studied. The main contents are detailed as following:1. The BP neural network and grey theory were used to predict the elevation of the subsequent segment. On the alignment control engineering practice, the comprehensive application of neural network and grey theory is better for the alignment control of the continuous beam bridges, and can meet the requirement of the alignment control.2. Based on the main effect factors analysis of the strain testing errors, the strain modified theory is put forward in this paper. The application results show that this method can effectively monitor the actual force status during bridge construction.3. The temperature-effect analysis of the continuous beam bridge shows that in the cantilever construction process, the sunshine temperature difference and the annual temperature difference of the beam have a great impact on the deformation of the beam, but have less impact on the stress. 4. The alignment control method, strain modification method and the temperature-effect analysis method proposed in this paper are successful to predict alignment, modify structural stress and temperature-effect analysis for the continuous beam bridge of the Ha-Da passenger dedicated railway and the Wen-Fu passenger dedicated railway.