The Analysis On Hydration Temperature Effect Of Continuous Box Girder And Calculation On Bridge Stress State

Cantilever casting prestressed concrete continuous box girder bridges, because ofits various advantages, occupy a pivotal position in the construction of bridges, andwith the increasing size of the box girder cross-section, the improvement of concretestrength, continue to develop.Heat of hydration effects of the large volume concrete, the stress state in eachconstruction phase and full-bridge phase, are issues of concern by the engineeringsector. Take the Weihe River Bridge of Xi'an to Tongchuan Expressway ExtensionProject, aimed at these three aspects of the problem, to carry out a computationalanalysis on the basis of summing up the existing research status. For the fact ofhydration temperature effect in mass concrete, focus in the construction process of0_#1_#blocks concrete, temperature and strain status being monitored, at the same timeto use heat of hydration analysis module in MidasFEA to conduct theoretical analysis;though comparison of measured and theoretical values related to temperature andprojections stress by strain, to verify the accuracy of the finite element model; on thisbasis,0_#1_#blocks hydration temperature and stress field all be calculated, and made aseries of measures to reduce the heat of hydration effect of the mass concrete. Joint touse MidasFEA and MidasCivil to calculate the stress status of0_#1_#blocks concrete inthe statge of maximum cantilever, and the stress state of side span close stage. Finally,by the use of MidasCivil, calculate the stress status of full-bridge phase in the effectof permanent and variable effect. The results shows that,0_#1_#blocks of concrete inthe hydration heat process, larger stress sector is in diaphragm and web of box girder;in largest cantilever stage and the side span close phase,0_#1_#block web and flangeplate stress is larger; in the most unfavorable load combinations, temperature gradientpositive temperature difference make it upward deflection in the middle of the sidespan, a larger negative moment near the box girder concrete of top bridge pier.The main research, provide a comprehensive and reliable guarantee for thequality control of the whole process of the Weihe River Bridge Construction, andactually provide a reference for similar projects.