Characteristics Of Wind Load And Design Wind Load On Claddings And Components Of Saddle Roof

As a kind of typical spatial structure, saddle roofs are widely used in the actual projects. At present, the study of characteristics of wind loading on large-span saddle roofs is still weak. The current wind load specification cannot meet the wind load requirements of the claddings and components of saddle roof. Therefore, further study on the characteristics of wind load and design wind load not only has theoretical research value but also has certain value.Based on the wind tunnel test data of the large-span saddle roof, the study on the distribution of wind loading has carried out. The conical vortex formed on the saddle roof is analyzed in qualitative and quantitative. According to the fluctuating wind pressure power spectrum on the roof surface, the energy and movement of conical vortex is explored. And the roof is divided into several zones, providing the basis for the wind load design of the actual engineering. The main content is shown as following,1. The distribution of mean wind pressure coefficients and fluctuating wind pressure coefficients is summarized. And the effect of the wind attack angles and rise-span ration on distribution of wind pressure is investigated.2. Based on the measured pressure on the saddle roof, models of describing mean pressures under vortex are proposed using the point vortex model, the Rankine vortex model and the Cook model respectively. The result of mean wind pressures is predicted which is compared with the measured wind pressure.3. The characteristics of fluctuating wind pressure spectra on saddle roofs are discussed. The connection between the shape of the spectrum and the separation, and then shedding off of the conical vortex is established. So it will provide reference for further analysis of wind induced response and fatigue resistant design.4. Extreme-value estimate methods are compared. The evaluation about the methods is given. The distribution of extreme wind pressure coefficients is summarized. The most unfavorable attack angles and positions are determined. Based on the envelope diagram of extreme wind pressure, the saddle roof is divided into several zones. A design wind pressure coefficient is assigned for each zone for the actual engineering.