Analysis On The Characteristics And Model Of Temperature Field Of The Box Girder Section In Jiujiang Cable-stayed Bridge

The temperature effect of concrete box girder will produce structure stress and deformationwhich affects the safety of bridge operation. It has practical engineering significance to theresearch of temperature field of the bridge. Based on the long-term health monitoring system onJiujiang cable-stayed bridge, the uninterrupted continuous monitoring of the temperature field onthe concrete box girder bridge has been carried out. According to the temperature data obtained by30temperature sensors in the concrete box girder, daily temperature field and yearly temperaturefield of measuring point, temperature distribution along the longitudinal and transverse directionfor girder, the model of daily temperature field and yearly temperature field is studied. The maincontents in this paper are as follows:(1) Jiujiang bridge structural health monitoring system and its layout of the sensors areintroduced. The factors influencing concrete structure temperature field and the correspondingparameter calculation theory are summarized and the temperature field observation of theconcrete box girder has been carried out.(2) Selecting the typical monitoring data for different seasons as samples, the dailytemperature fields on the concrete box girder flange plate and respectively the floor are analyzed,the time-varying rules of the daily temperature fields every measuring point on the flange plateand bottom of girder are obtained, and the temperature field distributions along the longitudinaland transverse direction of girder are also achieved.(3) Taking two typical time data at12:00and0:00every day as samples, the yearlytemperature fields on the concrete box girder flange plate and the floor and the its distributionsalong the longitudinal and transverse direction of girder are studied. the characteristics of theyearly temperature field and the temperature characteristics under the different season for Jiujiangbridge have been got.(4) Using a full cycle of sine function to describe the daily temperature variation and a halfsine to show the annual variation characteristics of temperature respectively, the predictivemodels of the daily temperature field and annual for Jiujiang bridge have been established.