CONSTRUCTION METHOD FOR STEEL PLATE GIRDER

摘要

A manufacturing method of a steel girder is provided to manufacture a steel girder for a bridge more economically by controlling section force occurring on a lower edge by the dead weight of an I-shaped steel girder effectively. A manufacturing method of a steel girder comprises the steps of: installing an I-shaped steel member(100) to make two ends supported simply, thereby making compressive stress and tensile stress applied to an upper edge and a lower edge of the I-shaped steel member by the dead weight of the I-shaped steel member; manufacturing an I-shaped steel girder(300) with improved cross sectional stiffness by forming confined concrete for cross section expansion(200) which is reinforced or unreinforced concrete on a lower flange of the I-shaped steel member by installing a form to a lower flange of the I-shaped steel member and placing, curing concrete to the form, thereby making the compressive stress and the tensile stress confined, and expanding a cross section of the I-shaped steel member by the confined concrete for cross section expansion; and turning over the I-shaped steel girder with the stress confined by the confined concrete for cross section expansion, and then piling up in a yard, thereby making tensile stress applied on the lower edge of the overturned I-shaped steel girder not to cause ultimate compressive stress on the overturned I-shaped steel girder or excessive compressive stress on the confined concrete for cross section expansion to resist the dead weight of the I-shaped steel girder or the slab concrete load and live load such as traffic load added on a following I-shaped steel girder effectively.