CHARACTERISTICS OF TRANSVERSE TEMPERATURE DIFFERENCES OF STEEL BOX GIRDER IN RUNYANG CABLE-STAYED BRIDGE USING LONG-TERM MONITORING

Based on long-term monitoring data measured by the structural health monitoring system instrumented on Runyang Cable-stayed Bridge, the thermal characteristics of the steel box girder in Runyang Cable-stayed Bridge are analyzed using one-year temperature data. By means of statistical methods such as the clustering analysis, correlation analysis, extreme value analysis, parameter estimation and hypothesis testing, the representativeness of screening temperature samples and symmetry of statistical characteristics of temperature are verified, and the statistical characteristics of transverse thermal differences of a steel box girder are investigated. The analysis results reveal that the transverse distribution of statistical characteristics of temperature is symmetrical, and there exist dominant transverse temperature differences in the top plate of the steel box girder. The probability distribution models of extreme values of the transverse temperature differences are further established, based on which the thermal difference standard values in a 50-year return period are obtained. Moreover, the four types of transverse thermal gradient models with regard to the top plate are presented. These research results can supply references for the life-cycle design and evaluation of long-span bridges.