HALF-CIRCULAR AND HALF-ELLIPTIC EDGE MODIFICATIONS FOR INCREASING AERODYNAMIC STABILITY OF STRESS-RIBBON PEDESTRIAN BRIDGES

A wind tunnel study was conducted to examine the aerodynamic stability of concrete stress-ribbon pedestrian bridges with special reference t o the Jomon Bridge. Not popular triangular fairings but half-circular and half-elliptic modified edges on both sides of decks were examined as a fundamental study prior to the Jomon deck model test. The modific ations are found to be effective in increasing the critical flutter sp eed V-F as well as suppressing vortex excitation. It was found in the Jomon deck model test that V-F was below the design speed for the deck with a conventional cross-section and that V-F was greatly increased by the similar edge modifications and a pair of half-circular cylindri cal fairings as well. Based on the test results and for some reasons, the half-circular fairing was applied to the actual bridge.