Connections of Steel Girders with End Plates and Partially Prestressed Bolts

The connections with end plates and bolts can be used in steel bridge structures, or joining the decking beams, which can lead to very simple and economical constructive solutions. The paper presents some theoretical aspects concerning the behavior and calculation of the end plate connections which is partially pre-tensioned by high-strength bolts, and supplementary a welded cover plate is added to the tensioned flange of the plate girder. In the case of connections subjected to tension forces, it is not recommended to prestress the bolts as much as is the case when the joints are subjected only to shear because live loads can lead to the overloading of the bolts; the overload is a function of the relative stiffness of the end plate and of the bolts. The additional welded splice at the tension flange contributes to the transfer of the large tension stresses from the extreme bolts to the welded cover plate, resulting in a significantly reduced joint assembly loading and an increased load-bearing capacity. The paper includes a numerical example highlighting the influence of the stiffness of the joint elements and of the welded splice-plate on the joint loading, considering its pre-tensioning effect from the cooling contraction of the longitudinal welding fillets.