Measurement And Analysis Of Transverse Stress By Sunshine Temperature Difference In The Box Girder Roof

Because of its good general mechanical properties and spanning capacity,concrete thin-walled box girder has been widely applied in the structure ofmodern long span bridge since1970s. However, whether the construction stageor the use of stage, one or more longitudinal cracks will usually be found underthe roof line edge. Previous researchers showed that the main reasons forcausing the crack are the temperature stress and wheel loads.The temperaturestress has to arrive or even exceed the stress of live load.When the firstprestressed box girder construction generally vertical transverse prestressedtension, but there is no pavement insulation effect under study the role of boxgirder construction phase sunshine temperature difference of the forces on theroof the roof cracking prevention of major importance.This paper is under the background of steep bridge engineering, getting theactual temperature gradient by combining temperature measurement of site withformula, getting the roof transverse thermal stress by measuring the Stress ofsite. by using the software ANSYS to calculate and analysis the temperaturechange of the lateral edge of the roof under stress parameters and underdifferent sections of difference temperature, and compare the impact ofSunshine Thermal Stress and weight effects on the roof cracking.Analysis of thelateral variation of the vertical temperature gradient temperature stress causedby different parameters box girder cross-section, compared the effects ofthermal stress and weight effects of sunshine on the roof cracking. Come underthe effect of sunshine temperature difference caused by temperature stress is thedecisive factor in the conclusions of the roof cracking.Indicate reinforcedconcrete and prestressed concrete highway bridge design specifications (JTGD62-2004) is given only formula vertical temperature stress is not sufficient.