不同地貌下几个典型屋盖的风压特性

在均匀流场、市郊地貌及城市地貌中对包括双坡、球壳及柱壳的几个典型屋盖进行了风洞试验,利用同步多点压力扫描技术得到屋盖的风压数据。将分布于屋盖的局部体型系数与建筑结构荷载规范进行了比较,讨论了不同地貌及风向角对屋盖风压的影响,分析了各风向角下的绝对值最大的负局部体型系数及出现的位置。发现位于双坡屋盖的屋角、屋檐及屋脊区域的风压远大于其它区域的风压,均匀流中这些屋盖的平均风压是市郊地貌屋盖的2至3倍,而市郊地貌屋盖的平均风压又是城市地貌屋盖的2至3倍。

Characteristics of wind pressure on typical roofs under different terrain conditions

The wind tunnel tests of several typical large roofs,including a pitched roof,domes and a cylinder,were carried out with various terrains which cover uniform approach,suburban and urban exposures.The wind pressure data of roofs were obtained by using the synchronous multi-pressure scanning technique.The local shape factors of wind load distributed over roofs are compared with those specified by "Load code for the design of building structures".The effects of various terrains and different wind directions on wind pressures of roofs are discussed.And the negative peak local shape factors under each wind direction with their positions are analyzed.It is found that wind pressures located on corners,eaves and ridges of pitched roof are much greater than those located on other areas,and mean pressures of these roofs exposed to the uniform approach are 2 or 3 times those exposed to the suburban terrain,and mean pressures exposed to the suburban terrain are 2 or 3 times those exposed to the urban terrain.