Numerical Simulation Of Wind Pressures On And Wind Environment Around Large-Span Structures

Owing to the ability of providing as large space without inner columns as possible, large-span structures are widely used in buildings such as stadiums/gymnasiums, exhibition centers and airport buildings. This kind of structure is usually sensitive to wind loading due to their light self-weight, large flexibility and complex geometric shape properties. Wind load often becomes the governing live load of this kind of structures. How to accurately predict the global and local wind pressures on the structure is an utmost important problem in the structural design process. On the other hand, the density of pedestrians around this kind of buildings is often large. Therefore the problem of wind environment around the building is of great concern by common people and researchers.This thesis studies the wind pressure distribution behavior and wind environment problem for large-span roof structures using the numerical simulation method. In the thesis, after presenting the previous important achievements of study in this area, the basic theory including the governing equations for the numerical prediction is first established. A numerical procedure based on the averaged Navier-Stokes equation and the two-layer turbulence enclosure model is adopted in the prediction. The scheme of governing equation discretization, boundary condition and iterative algorithm for solution of discretized equations are then described in detail.As an example the two-layer turbulence model and the standard k-e model are used respectively to predict the wind pressures on a two-dimensional low-rise house model. The obtained pressures are compared with the wind tunnel test results and good agreement is found. This demonstrates the accuracy and validity of the numerical method. Meanwhile comparison and discussion are given to the numerical results predicted by the two turbulence models. As the second example, numerical simulation is carried out to predict wind-induced pressures on and wind velocities around a real large-span structure-Jingangshan airport building. Through comparison with the wind tunnel test results the distribution behavior of windpressures on this kind of structures is summarized. Finally, criteria for evaluating the degree of comfort of the wind environment around buildings are described and discussed. The wind environment in different areas around the Jingangshan airport building is then numerically predicted and the degree of comfort of the environment is evaluated. Several proposals for improving the confort of wind environment are presented in the same time.