Recent Aerodynamic Studies of Long-Span Bridges

Wind forces have taken on increased significance and can be a major problem in the design of cable-supported bridge systems. The determination of the response of long-span bridge structures due to wind action is obtained by field observations and wind tunnel testing of models, or both. Current cable-stay bridge designs are subject to the same fundamental wind excitation as the classical suspension bridge; however, the inherent increase in stiffness of the cable-stay box-girder does place it in a different realm of response. Preliminary data are presented relating angle of attack and wind velocity obtained at the Newport, R.I., Suspension Bridge over Naragansett Bay during Hurricane Doria; field observations of the vortex excitation of the pylons of the Sitka Harbor Cable-Stayed Bridge; and wind tunnel tests of the Luling, La., Cable-Stayed Bridge. Results of the wind tunnel tests of the Pasco-Kennewick concrete Cable-Stayed Bridge are also presented.