Analysis Of Regional Difference Of Temperature Action Of Concrete Box Girder Based On Meteorological Parameters

In general specification for design of Highway bridges and culverts(JTG D60-2015),the concrete box girder design adopted uniform temperature action in different regions.The influence of factors such as geographical location and topography on the value of temperature action was not taken into account,while China is a vast territory with a large difference between regions,so it is necessary to further discuss whether the specification is reasonable.Based on the middle bridge above Xiaosha River and Guangdong Changping 6th viaduct,the paper studied regional difference of temperature action of concrete box girder through the temperature field test,temperature action statistical analysis,temperature field simulation analysis,parameter analysis,etc.The main research contents are as follows.(1)This paper summarized the research status of concrete box girder temperature field at home and abroad and the specifications on temperature action,analyzed the deficiencies of current research and determined research content and technical route.(2)Based on measurement data of box girder temperature field,this paper studied the characteristics of temperature distribution,determined the mode of temperature action,and analyzed the regional differences of temperature action in Xinjiang and Guangdong.(3)This paper used generalized extreme value statistics to analyze Guangdong Changping 6th viaduct measurement data and calculated the generalized extreme value distribution of temperature action characteristic value T1,T2,the diagnosis model results showed that the results can reflect well the distribution T1 and T2.With the return period of 50 years as the standard,the representative value of temperature action in Guangdong Changping 6th viaduct area was T1=17.3,T2=3.1.(4)This paper Summarized the basic theory of heat transfer and the commonly solar radiation calculation model.Based on meteorological data,the temperature field simulation model of concrete box girder was established,and compared simulation results based on different solar radiation models with the measured temperature,the results showed that Hottel clear-sky model is more accurate in the simulation analysis of concrete box girder temperature field.(5)Based on temperature field simulation model of concrete box girder,the paper analyzed region parameters and determined the relationship between the characteristic value of temperature action and the region characteristic parameters.(6)Based on the representative value of temperature action in Guangdong Changping 6th viaduct(T1=17.3,T2=3.1),according to the relationship between the characteristic value of temperature action and the region characteristic parameters,this paper calculated representative value of temperature action of 361 urban areas and divided it into four areas,and each area temperature action suggested values is given.