Research On Temperature Effect Of Railway Concrete Partial Cable-Stayed Bridge Based On Long-term Monitoring

After many scholars have studied the temperature effect of bridge structures for more than half a century,a set of relatively complete calculations and methods for considering temperature effects have been established in national design codes.However,due to the complexity of concrete temperature field and the influencing factors affecting the temperature effect of bridge structure,the research and specifications of some special bridge structures such as concrete partial cable-stayed bridges need to be further improved.This paper takes the Dongping Waterway Bridge in Foshan City,Guangdong Province as the research object,and carries on the long-term monitoring of the temperature field of the main bridge box girder of the concrete part of the cable-stayed bridge for more than one year,and based on the processing of the measured temperature data and the finite element software.The calculation of the influence of the temperature effect on the cable-stayed bridge of the railway concrete section has been studied in the following aspects:(1)The structural characteristics,development overview and future development trend of some cable-stayed bridges are introduced,and the research process and research status of concrete bridge temperature effects are summarized.From the characteristics of temperature load,the research theory and solution method of temperature field,the theory and calculation method of temperature stress,the analysis theory of bridge structure temperature effect is introduced in detail.(2)The temperature sensor arrangement is optimized by the difference fitting method.According to the measured temperature data,the temperature distribution of the roof,the temperature distribution of the web and the temperature distribution of the bottom plate are analyzed in detail under the action of sunshine and cold wave.The box beam temperature distribution characteristics.(3)Using the correlation statistics,the linear formula of the maximum positive temperature difference between the local maximum temperature and the box girder day is given.The extreme value statistical analysis is carried out on the measured box girder temperature by extreme value statistical theory.The generalized extreme value distribution of the maximum positive and negative temperature difference of the box girder web is obtained,and 100 years are calculated according to the obtained generalized extreme value distribution.The maximum positive and negative temperature difference extreme values of the return period are given,and the positive and negative temperature gradient distribution curves of the box girder webs in the 100-year return period are given.(4)Through the establishment of the Midas Civil finite element model of the bridge state and the maximum cantilever state,the overall calculation and analysis of the overall rise and fall temperature of ± 25 ° C,as well as the specification and the calculation of the difference between the base plate temperature difference and the base plate temperature difference are considered.The negative temperature gradient has a total of six temperature gradient modes,and the temperature effect of some cable-stayed bridges.