L形平面低矮房屋屋面的风荷载特性

Wind Loading Characteristic of Lowrise Buildings Roof with LShape Plan

摘要:

通过L形平面低矮房屋在同济大学TJ2风洞进行的刚性模型测压试验,首先对其屋面的风压时程概率分布进行了讨论,试验结果表明,屋面大部分区域的风压时程偏度较大,概率分布与三参数Gamma分布较为吻合,其极值的估算更适合用“SadekSimiu法”,且相比而言,传统的高斯方法偏于不安全.继而对翼长、坡度及组合屋面形式对屋面风荷载特性的影响进行了研究,试验结果显示,翼长的增加,坡度的减小均会加剧屋面的平均负压和最不利负压;而屋面由两双坡组合变为双坡、四坡组合后,屋面的平均负压和最不利负压都有大幅度的减小,从而得出双坡、四坡组合屋面的L形平面房屋比两双坡组合屋面更有利于抗风的结论.

Abstract:

Rigid model pressure measurement tests of lowrise buildings with Lshape plan were conducted in TJ2 wind tunnel laboratory,the pressure time histories probability distribution was discussed firstly.The experimental results reveal that the skewnesses of most regions pressure time histories of the roof are large,and the probability distribution is well fitted by the threeparameter gamma distribution,consequently,the SadekSimiu procedure is preferred to estimate the peak pressure coefficients,and compared with such method,the traditional Gaussian method tends to be unsafe.Then the effects on roof wind loadings of wing length,roof pitch and the roof combination form were studied.The results show that the increasing of the wing length or the decreasing of the roof pitch intensifies the negative mean pressure and the worst negative peak pressure,however,the negative mean pressure and the worst negative peak pressure on gablehip combined roof are much smaller than that on twogable combined roof,thus the conclusion is drawn that the gablehip combined roof is superior to twogable combined roof in wind resistance.