Study on economic design and construction program of steel-hybrid combined girder bridge

In order to make full use of steel tensile and concrete compressive properties, combined beam cross-section stress-strain distribution characteristics and cross-section characteristics and loading procedures are closely related. At present, the cross-section form of I-beam combined with concrete panel is widely used, and the strength of the upper flange of the steel beam of the supported combined beam and the strength of the concrete panel of the unsupported combined beam have not been fully utilized. Through the theoretical analysis of different loading methods of combined beam strain stress distribution, so as to optimize the cross-section form, the proposed supported combined beam using the lower inverted T-shaped cross-section combined with the form of concrete panels, in the given actual engineering cases can obtain a higher elastic ultimate bearing capacity and can save 9.5% of the amount of steel. The unsupported loading method of I-beam combination beams can use lower grade concrete for better economy. Making full use of the neutral axis position change to design the combined beam cross-section is operable, inverted T-shaped steel beams combined with concrete panel combined beams is a way to save steel and reduce the construction of welded joints, with significant economic benefits.