Research Of Numerical Simulation On Real-time Temperature Field Of Long-span Concrete Box Girder And Crack Control

Over the past 20 years, Box girder accounted for the vast majority of the bridge structure both at home and abroad because of its own unique advantages. And long-span prestressed concrete continuous bridge system usually adapted the form of box-section. However, a great amount of research show, prestressed concrete thin-walled box girder bridge can lead to typical large-scaled crack, for example, the inclined crack of web. The cracks affected the further promotion and application of box girder in the highway construction. Therefore, further study of prestressed concrete thin-walled box girder bridge cracks is very urgent and meaningful to improve the life and performance of the bridge and to provide useful lessons for design in the future so as to avoid similar problems.According to the study, the large number of cracks were caused not only by the loads, but also the effect of non-loads. And according to a large number of investigation and research, the non-load cracks were mostly caused by deformation, including the deformation of temperature, shrinkage and the uneven settlement of foundation. The stress caused by the tensile strength of concrete. Due to the strength that caused by the limitation of deform which exceeds the anti-intensity of concrete, it leads to the phenomenon of cracking.This paper combines with the progress of a bridge construction. Take the non-navigation bridge prefabricated concrete box girder as the study object. Make use of Midas/civil do FEM analysis for the prefabricated concrete box girder. First of all, simulate the changing rules of three-dimensional temperature field, stress field with time of long-span concrete. Measure the internal temperature of mass concrete on the site. Compare the calculated results and monitoring data, and put forward the control measures of temperature cracks and technical proposals by the comparing results.The control measures of temperature cracks and technical proposals mentioned in this paper provide useful information for the similar projects. And it provides the reference of experiments and theory for its further study.