Numerical Simulation Study On Wind Pressure Effected By Roof Construction Of Low-rise Buildings

It’s frequently affected by typhoon in China’s coastal city, and all the previous wind disaster were brought enormous casualties and property losses. However, the loss caused by low-rise building’s damage are of half of the wind disaster loss. Many typhoon investigation shows that local damage at the vulnerable area including roof corners, edges and ridge or its induced overall damage of the whole building are the two main modes of wind-induced damage of low-rise buildings. Therefore,The research of detail structure that contains ridge, protruding gable wall and the parapet influence on roof wind pressure are of a very important practical significance.This paper based on the wind tunnel test data of Tokyo Polytechnic University,use the numerical simulation method study on the building model of geometric size is 24m× 16 m ×12m. Compared with the same size of low-rise building wind tunnel test data, the numerical simulation based on RNG k-ε turbulence model can accurately predict wind pressures on low-rise buildings. Low-rise buildings roof wind pressure is affected by many factors, with the 0° wind angle at the direction of flow vertical the short edge by the house, this paper concluded that as the wind angle increases, the roof high negative pressure zone along the short edge by the house turn to the long side by analysising the influence of wind angle and slope angle to roof wind pressure characteristic. With the increasing of slope angle, the suction of windward roof bacame weaken, the negative pressure zone appeared in the area of leeward roof ridge line. On the basis of this model, with the wind angle as variables,in-depth study of local wind pressure characteristics of gable roof affected by the change of structure size. Research shows that, when the ridge height increased, the shape coefficient of windward roof increase. With the increase of the height of protruding gable wall, roof partition shape coefficient changes small. At vertical wind direction, the wind pressure coefficient of roof edge region decreased in the common role of ridge and protruding gable wall. But suction of windward areas becomes larger at oblique wind direction.A numerical study was performed on the influence of three kinds of parapet form(continuous high parapet, local parapet,corner raised parapet) in the local roof’s wind pressures distribution law of a flat-roofed low-rise building with a1.5:1:1 body type. The research results show that, when the parapet height is 0.6m,continuous high parapet and corner raised parapet can reduce more roof local pressure than corner raised parapet.Finally, based on the architectural wind load design methods and research results, providing theoretical foundations for the Quantitative calculation of wind load of low-rise buildings. and presenting the optimization method for wind-resistant design of low-rise buildings.