Temperature Effects on Box Girder for Changsha Medium-low Speed Maglev under Solar Radiation

The admissible value of the gap between the Maglev train and track beam is small, so the requirement of structural deformation in a maglev bridge is strict. However, under the effects of solar radiation, the box girder in a medium-low speed maglev bridge could induce noticeable temperature gradient, impacting the bridge deformation and the geometric alignment of rail. To determine the changing law of the temperature field and deformation, some temperature sensors were embedded in the concrete box girder and approximately one year temperature data were obtained. Based on the field experiment, the temperature field and the longitudinal and transverse temperature gradient of a box girder were discussed. In addition, a finite element model is established to represent the box girder of China Changsha Medium-Low Speed Maglev Railway, for studying the temperature gradients and thermal deformation of box girder under solar radiation. With the three-dimensional finite element model, the value of thermal deformation caused by the temperature gradient was discussed. Medium-low speed Maglev Bridge is a new structure, the research focused on the temperature effect is creative and meaningful to similar structure. It is hopeful that the findings from this study provide some insights on the temperature distribution of a box girder and the temperature effects on medium- low speed maglev rails.