Construction Monitoring And Shear Lag Effect Research Of Wide Box-girder Continuous Beam Bridge

The box-section bridge is the most widely used form of among the cross-sections, and box-section beam has increasingly shown its advantages in cross-section in the form of bridge. In order to ensure the alignment and stress to meet the requirements in the construction process, this paper takes Shayinghe Bridge as the basis to have the numerical simulation and field measurement. As box-beam shear lag effect is more obvious for the rooms-section, so this paper is based on the finite element model and the theoretical analysis and other methods to study the effect of shear lag. The main work is as follows:(1) Use finite element analysis software Midas/Civil and Midas/FEA to build the models with beam element and solid element.(2) For the features of one box four rooms section, this paper monitors alignment and stress. With the help of finite element analysis model, this paper makes the reasonable prediction of the alignment. Use the deformation data of pre-press to calculate the value of elevation. The constructed bridge is in good agreement with the expected models. Exclude the impact of temperature on stress to get the more accurate values of the actual stress, and the comparison with theoretical values fundamentally changes within a reasonable range.(3) Study the impact of pre-stressed in shear lag effect. Take the example of #0, respectively in only the longitudinal, and the jointly pre-stressed effect to calculate and analyze the shear lag coefficient of roof and floor of section. And also take the example of full process of bridge construction to study the influence of the current construction segment shear lag effect of under longitudinal pre-stress. In the constructed stage, discuss the law of influence of pre-stressed box girder shear lag effect with several sections.