• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.659-672
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• 1997

Thermal response induced from nonlinear temperature distribution in composite box gilder bridges depends on several variables(environmental conditions, physical and material properties, location and orientation of bridge, and cross-section geometry). In this paper, parametric study are conducted in order to find the effects of variations of seasons, location and orientation of bridge, sectional geometry and some material properties on the axial deformation, curvature and stresses in composite box girder bridge. A two-dimensional transient finite element model to conduct this parametric studies is briefly presented. Firstly, the effects of the parameters on the diurnal variation of curvature are considered, and for the time of maximum curvature, on the distribution of temperature and stresses of composite box girder sectional are considered. Finally, some considerations about the influence of the parameters on the daily maximum values of axial deformation, curvature and stresses are carried out. The influence of thermal effect on structures is important as much as the influence of live or dead load in some cases. In the design of steel composite bridges, the thermal stresses calculated on the supposition that the temperature difference between the concrete slab and steel girder is $10^{\circ}C$ and the temperature distributions are uniform in concrete slab and steel girder can be underestimated.