ANALYTICAL INVESTIGATION OF PATCH PLATE FLEXURAL STRENGTHENING EFFECT AND ITS REQUIRED LEGNTH FOR STEEL MAIN GIRDER WITH A FIELD CONNECTION

Abstract

Strengthening of the steel main girder by patch plate is standardly used in redecking. In the case of strengthening across the field connection, patch plate needs processed like a bypass structure, however, strength effect is not clarified. In addition, strength length to achieve sufficient strength effect is not known. Thus, analytical investigation is conducted to clarify the strength effect of bypass structure and, to suggest the required strength length of patch plate. Based on the results, bypass structure decreases nearby panel web’s neutral axis, thus it needs to extend more than 1.5 panel from connection. Furthermore, patch plate needs to extend more than 1.5 panel from the end of required strength length to achieve strength effect.