Thermal Field of Composite Girder-Ballastless Track System on Arch in Plateau and Regions with Large Diurnal Temperature Variation Based on Measured Data
Thermal action is one of the key factors affecting the service performance of bridge-track structures.To inves-tigate the temperature field variation regularities of the composite girder-ballastless track system on arch,which is in plateau and regions with large diurnal temperature variation,based on the solar radiation data retrieved by satellite data and sustained temperature monitoring data of a proposed long-span railway deck arch bridge,a temperature field model of the composite girder-ballastless track system was established containing the shading effect of solar radiation,with a fo-cus on the analysis of the diurnal temperature variation and vertical temperature distribution.The annual daily-tempera-ture field simulation results were obtained considering the measured temperature and the hourly variation of solar radia-tion.The generalized Pareto distribution was used to estimate the extreme distribution of the maximum samples in the re-sults.With the determination of the representative values of vertical temperature differences with diverse exceedance probabilities,the vertical temperature gradient mode with polyline was proposed.The results show that the gradient in this paper is more significant than that in the plain area.The shading effect of the ballastless track causes the temperature gradient of the system to shift upwards,resulting in local gradient effects on the lateral web of the outside steel beam in winter.The stochastic effects of ambient temperature and solar radiation on the structural temperature field obtained from the measured data are included in the extreme temperature difference estimation method,which can provide reference for the calculation of temperature actions in the design stage of bridges in special areas.
composite girder-ballastless track systemthermal fieldshading effectvertical temperature gradientgener-alized Pareto distribution
万方数据
维普
