Vehicle roll-over stability in strong winds on long-span bridges

摘要

High-sided, lightly loaded vehicles are known to be prone to accidents in strong, gusty winds. While wind related accidents may occur anywhere on roads, vehicles are more sensitive to wind while passing over bridges given the higher road elevations, exposure and possible speed-up effects at various bridge locations compared to ground level roads. The paper presents an extended roll-over model for estimation of vehicle stability in strong, gusty winds. The study example is of a Double-Deck Suspension Bridge where four typical vehicles were investigated, including: a tractor-trailer truck; an intercity bus; a courier van; and a full-sized SUV. Using a sectional model of the bridge deck and vehicle models built in scale, six component force and moment coefficients were measured at various lanes for the full azimuth of wind directions. The effects of the road level were also investigated. Based on expected wind turbulence properties at the bridge site and measurements of wind flow modifications at various deck locations, vehicle stability against roll-over has been predicted for various wind and vehicle speeds. For calibration purposes comparative tests and analyses on the same vehicles were carried out for the Confederation Bridge, PEI, Canada, and the results compared with the adopted policy for traffic control in strong winds on that bridge. Recommendations for traffic management in strong winds on tested bridges were drawn.