Study On Temperature Field And Its Action On Steel Plate-girder Bridges

Plenty of researches have shown that the temperature effects of bridge impact the security during the construction and the reliability during the service. The researches on temperature and temperature effects of the bridge structure have risen many cares of the bridge experts and research workers both domestic and aboard. Because of the Good thermal conductivity, the temperature effects of the steel seem more notable. So far, different countries have various design standards on temperature gradient effects of bridge. Among these standards, the researches on the temperature gradient model of the steel plate girder bridge do not run deep. With the widely use of the steel structure in long-span bridges, the researches on temperature fields of the steel beam come more urgent.This paper bases on the Tennessee River Bridge in124. After observing the results of the temperature of the bridge, I choose some field test data of steel beam temperature and thermal deformation under typical weather and seasonal conditions. Meanwhile, with the aid of the finite element software, SAP2000, I try to study the temperature field and the temperature effect of steel plate girder under the sunshine. The main work and achievements of this paper states are as follows:(1)The field test on temperature field of the Tennessee River Bridge under the natural environment has finished, from which we can get the continuous data of temperature and the temperature deformation in the steel beam.(2)According to the data measured, I try to analyze the relationship between the steel beam temperature and time, between the steel beam temperature and space, then to find the variation rule of the steel beam temperature, to make sure the most adverse temperature gradient under the sunshine, to compare with the standards of different countries, and finally to put forward the vertical temperature gradient model along the steel beam height direction.(3)The detailed analysis has been made which is aiming at the rule of the day-time and the long-time temperature deformation of the steel beam. The comparison between the standards of different countries has also been made, so does the analysis on the relationship between temperature deformation and uniform temperature and the temperature gradient, in order to provide the basis to the design which has the similar form of main beam.(4)Combined with the project, I try to model the temperature field of the whole bridge using the finite element software SAP2000. And I introduce the measured temperature field to the model, to find the theoretical deformation of the bridge, then to compare and analyze the measured deformation with it, just to confirm the feasibility of the model.(5)According to the results of this paper, from the viewpoint of the influence of the temperature variation, I try to give some advices to the setting of the expansion joints, which is used in concrete bridge deck of the steel plate girder bridge. The results of the paper mainly focus on providing references for the design and calculation of the setting of the expansion joints in the future.