Observation Research And Probability Statistical Analysis On Temperature Field Of Concrete Box Girder

Temperature effect is an important factor in the design of concrete bridges, the selection of the temperature gradient has an important influence on the bridge design security and economy. Based on the long-term monitoring data of a large span continuous rigid frame bridge in Qiandao Lake, Zhejiang Province, the temperature field of the concrete box girder is analysed.Select a month as a representative of summer and winter respectively, plot the temperature curve, and analyze the variation of temperature over time, compare the measuring point which distance the top surface of the box girder in the longitudinal and transverse direction. Meanwhile the impact of asphalt pavement is analyzed.A statistical analysis on the relationship between the vertical maximum positive temperature difference and the ambient air temperature was conducted. A formula based on the daily maximum air temperature and daily air temperature amplitude to estimate the box girder vertical maximum positive temperature difference was established.The clause related to temperature loads in bridge specification of different country is introduced. Reference these specifications, based on the measured data, the recommended temperature gradient design curve in Hangzhou is proposed through statistical probability analysis, it can be used as the reference of concrete bridge design in this area.According to solar physics, astronomy and the theory of heat transfer, the study of concrete bridge structure with the environment heat transfer mechanism is conducted, the boundary conditions of sunshine temperature field of concrete bridge is established. The numerical model is established and it can calculate the temperature filed with arbitrarily complex boundary conditions of concrete box girder.Solar temperature field is calculated by Abaqus. The influence of thermal physical parameters of concrete, asphalt pavement thermal physical parameters, pavement layer thickness, and environmental factors such as ambient temperature to the temperature field of box girder are analyzed and the sensitivity curve of amplitude To and index a are drew.