Buckling prevention structure for steel closed cross-section members of steel bridges

摘要

To provide a buckling prevention structure for a steel closed section member that improves the seismic performance of existing steel bridges, and has excellent closed space airtightness, watertightness, and workability in the steel closed section member, and its construction method.SOLUTION: A flange of a T-section stiffener 156 is placed along a lower chord member 121 on an outer surface of a web 150, avoiding positions of diaphragms 145, 148. Each of a plurality of bearing joint bolts penetrate the flange of the stiffener 156 and the web 150, and a female thread is formed on a hole wall by itself to form a bearing joint hole by being screwed into each bearing joint pilot hole having a diameter smaller than the shaft of the bearing joint bolts. The flange of the stiffener 156 and the web 150 of the lower chord member 121 are then bearing pressure bonded. Buckling of the lower chord member 121 is prevented to improve seismic performance, and airtightness and watertightness is secured for the closed space of the lower chord member 121. This can be realized with simple workability on the outside of the lower chord member 121 without traffic restrictions or road closures.SELECTED DRAWING: Figure 3