Study on effect of temperature on dynamic characteristics of three-cell box girder
The box girder is widely used in engineering because of its good structural characteristics.The temperature will affect the dynamic characteristics of the box girder.The stress and deformation of concrete box girder caused by temperature directly affect the safety,durability and applicability of concrete structure.In order to study the influence of temperature on the dynamic characteristics of the box girder,an experimental study of modal recognition based on environment was carried out upon Feng River Bridge in Shaanxi Province under different temperatures.Due to special reasons,the construction of the bridge needs to be suspended to the current position.Therefore,the bridge is in a closed state when the dynamic characteristics test is carried out,so as to avoid external interference.The natural frequencies and modals of the structure are obtained by experiments,and the experimental results are compared with the finite element results.On this basis,the correlation between dynamic characteristics of box girder and temperature variation is analyzed.The results show that in the short term,there is no obvious positive or negative correlation between the influence of temperature on the box girder's natural vibration characteristics.The increase of temperature will make the temperature of the box bridge structure more uneven,and the influence on its natural vibration frequency is greater and the influence on the low order frequency is more obvious.
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