Wind force coefficients for the design of supporting systems of large canopies attached to low- and middle-rise buildings with flat roofs

Wind tunnel experiments have been conducted to investigate wind loads on large canopies attached to low- and middle-rise rectangular buildings with flat roofs. The canopy is assumed to be supported by beams. Two types of structural systems, the cantilever type and the hanger-rod supporting type, are considered. Wind pressure distributions along the center and edge lines both on the top and bottom surfaces were measured in two kinds of turbulent boundary layers corresponding to open-country and urban terrains. The effects of the ratio of canopy height to roof height, h/H, and wind direction on the wind forces were investigated. The results indicate that the wind direction providing the maximum load effect (i.e., bending moment M or shear force Q induced by wind) depends on h/H and the location of the beam, significantly. Based on the results, the wind force coefficients for designing the two types of structural systems are proposed, in which main focus is on the maximum bending moments induced in the beams as the most important load effect.