Concrete Additional Stress near Intermediate Support for Composite Girder Bridges with Corrugated Steel Webs

Abstract

This paper proposes an innovative method to calculate the normal stress of concrete slabs near the intermediate support for composite girder bridges with corrugated steel webs (CSWs). The shear stiffness of CSWs is lower than that of concrete webs, which will lead to significant shear deformation. For composite girders near intermediate supports, the shear deformation of CSWs will be constrained by the crossbeam, resulting in additional stresses in the top and bottom concrete slabs. The constrained effect of the shear deformation is not considered in most design codes, which will lead to unsafe designs. Therefore, analytical solutions of the concrete normal stress under different boundary and load conditions were derived based on the elastic bending theory considering the shear deformation of the CSWs. Experimental analysis and finite-element analysis (FEA) were carried out to further validate the analytical solutions. The results show that the proposed analytical equations can be used to accurately predict the normal stress of concrete slabs. The additional stress exists in the concrete slabs near the intermediate supports, and the plane-section assumption is not applicable in this area. The value of the additional stress decreases to zero with the increase of the distance from the fixed end. The additional stress is in the same direction as the general bending stress at the upper edge of the top concrete slab and the lower edge of the bottom concrete slab, which will increase the peak tensile and compressive stress of the whole section. Finally, a practical simplified calculation method of the concrete normal stress near the intermediate supports is proposed, and the calculation procedure is plotted. All the findings can be used for the design of composite girder bridges with CSWs.