Abstract:Conical vortex and the induced wind load on saddle roof are investigated by wind tunnel test. The mean and fluctuating pressure distribution associated with conical vortex on saddle roof are presented and discussed, with emphasis on the mechanism of wind pressure characteristics along the leading edge. Some character parameter of conical vortex, such as the axis of the conical vortex and the coverage area, are identified through contour maps of roof surface wind pressure coefficient. The sway of the axis of conical vortex is analyzed, on the basis of which the qualitative and quantitative relations between conical vortex movement and suction fluctuation on roof surface are established respectively. Based on the third and fourth order statistical moment of wind pressure, non-Gaussian region on roof surface is located. The mechanism of non-Gaussian feature related with conical vortex is also clarified.