屋盖开孔的近地空间建筑的平均风压特征

对开孔位置和开孔率不同的7个屋盖开孔近地空间建筑进行了缩尺刚性模型测压试验,分析了屋盖升力系数,屋盖中线测点和立墙测点的点体型系数,以及屋盖的块局部体型系数分布规律,并与当前规范取值进行比较,结果表明:屋盖中心开孔减小了屋盖向上的净平均风吸力,屋盖轴线测点最大正体型系数可达+0.32,中心开孔屋盖设计时应充分考虑正风压作用;屋盖角部开孔时的正风压较中心开孔工况大,对结构受力不利;中国规范对于屋盖中心开孔工况的角部块Ra的局部体型系数取值偏于不安全;屋盖角部开孔后局部块受风的压力作用显著,会导致屋盖的进一步破坏;屋盖中心开孔增大了迎风面立墙正风压86%以上,减小了侧墙和背风面立墙的吸力,使得在全封闭状态下承受风吸力的背风面墙转而承受风压作用。

Mean wind loads on a closing-ground building with a roof opening

The effects of seven different roof opening configurations on the net mean wind loads in a closing-ground building were examined using wind tunnel tests. The lift coefficients of roof, shape coefficients of center-line taps on roof and wall, local shape coefficients were specially studied and compared with the values from Code. It is shown that the net mean suctions on the roof are reduced for the configuration of roof center opening, the biggest value of positive shape coefficient on the center-line is +0.32, which should be taken account into the design of structure efficiently. The positive wind pressures in the configuration of roof corner opening are larger than that of roof center opening configuration, which are unfavorable for structure. The Chinese Code was found to significantly underestimate the local wind pressures of corner area Ra for roof center opening configuration, and the local wind pressures for roof corner opening configuration are larger than that of roof center opening configuration, which may be the result of continuing destroyed for the building. The positive wind loads on the windward wall are increased for roof center opening configuration, up to 86%, and the suctions on the backward and leeward wall are reduced largely.