Research on the Calculation Methods for the Carrying Capacity of the Cross Section of the Bending Member Reinforced with an Enlarged Section

Abstract

Regulations on relevant design specifications are comparatively analyzed to expediently calculate the carrying capacity of the cross section of the bending member of a bridge reinforced with an enlarged section. Five different failure forms of the bending member strengthened with the enlarged section are analyzed, along with the advice on modifications propounded by some experts and professors who apply the said regulations. Results lead to the conclusion that the B-class failure form of a suitable reinforced beam is impossible. This failure occurs when new tension steels do not yield but old tension steels do yield. Based on the conclusion of the present study on damage forms, the calculation formula for the carrying capacity of the cross section of bending beams strengthened with enlarged sections is obtained, and the scope of application is extended to increasing the concrete sections on the tension and compressive zones, as tested by engineering examples. The calculation method is simple and relatively safe and has already been adopted in the