Wind and vehicle induced forces on flat plates. Part 1: Wind induced force

The current UK standard for the determination of wind loads on temporary road signs is generally perceived by the industry to be unrealistic. To enable a rational revision of the standard to take place full scale data have been collected on the wind induced force acting on a representative range of 750 mm road signs, 1500 mm road signs and a pedestrian barrier. These have been expressed as non-dimensional coefficients of force based on sign area and wind speed. Sign shape appears to have no significant effect on the magnitude of the wind force coefficient but the inclusion of a mounting frame around a sign does increase its susceptibility to wind induced forces. Nominal sign size (750 or 1500 mm) appears to have some effect on the overall force coefficient, with larger signs experiencing more severe wind forces. This effect may be partly due to the proximity of the 750 mm signs to the ground. Spectral analysis of the sign response shows a general agreement with wind tunnel data for flat plates with, however, increased response in the reduced frequencies range 0.1-1. This is perhaps due to the asymmetry of full scale turbulent eddies near to the ground. The results presented form part of a wider study, which included the wind and vehicle induced effects on flat plates in the atmospheric boundary layer. (C) 2001 Elsevier Science Ltd. All rights reserved.