Influence To Wind Pressures On The Roof Of Low-rise Gable-roofed Buildings With Cantilevered-Parapets

In recent years, typhoon attacks the coastal areas of our country frequently and causes severe damage to the coastal provinces,what's more, it has been increasing obviously year by year. Previous wind disaster surveys indicated that more than half of the low-rise buildings especially the typical light-weight steel buildings in coastal industry-concentrated regions were destroyed seriously in the wind disaster. Therefore, it is of great significance to investigate the wind-load characteristics of the light-weight steel gable roofed buildings which represents the low-rise buildings and find out the corresponding ways to optimize the structures to meet the wind-resistant design requirements.In this dissertation, the wind tunnel experiment and CFD numerical simulation techniques were employed to study the wind-induced pressure distributions on the typical low-rise gable roofed buildings (the light-weight steel building) with cantilevered parapets in different heights and different widths based on the existing research achievement, and then the corresponding conclusions and optimizational parameters of the height were put forward.At first it summarized the existing research achievement of the wind-resistant status of low-rise buildings and the wind character on the roof of low-rise buildings home and abroad in this paper, then lucubrated them and elaborated the wind character in atmospheric boundary layer and the factors that have effect on the wind load on the roof, and analyzed the wind-induced damage mechanism of the low-rise roof, and then amply discussed the basic foundamentals of CFD numerical simulation and techniques. Then the wind tunnel test was adopted to the study of the influences of the wind pressure on the roofs in the cases that horizontal cantilevered parapet in different height were installed to the roofs of the mass extensive typical low-rise gable roofed buildings in the coastal typhoon-prone areas. As a result, it educed the optimization design height of the horizontal cantilevered parapet in this experiment model. And then in this paper further plentiful CFD numerical simulations based on the previous experiment were carried on to study the characteristic of wind load on the roofs of the low-rise buildings with horizontal cantilevered parapet in different height and different width. Consequently, a more comprehensive and systemic analysis of wind pressure distribution on the roof on the impact of additional horizontal cantilevered parapet of different size turned out in comparision with the results of the wind tunnel test . The comparision results showed that the horizontal cantilevered parapets could obviously reduce the peak of the negative pressure on the roof of the low-rise buildings. The desired effect lied on the parapet wall with reasonable height and width. Finally, relevant useful conclusions and the optimizational parameters of horizontal cantilevered parapets were drew according to the wind tunnel experiment and the results of numerical simulations.The research results and the optimizational parameters obtained in this paper can be applicable to wind-resisting design of low-rise roofed buildings, and also they can be served as references to the relevant regulations of the wind-resisting design of low-rise roofed buildings in the wind disaster regions.