低矮房屋风荷载实测研究(Ⅱ)——双坡屋面风压特征分析  

Field measurements of wind loads on a low-rise building——Part Ⅱ:Wind pressure distribution characteristics on gable roof

作　　者：李秋胜[1,2] 胡尚瑜[1] 李正农[1] 

机构地区：[1]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082 [2]香港城市大学,中国香港999077

出　　处：《土木工程学报》2012年第4期1-8,共8页China Civil Engineering Journal

基　　金：国家"985"工程湖南大学"现代结构与桥梁科技创新平台";国家自然科学基金重大研究计划"重大工程的动力灾变"(90815030);"十一五"国家科技支撑计划(2006BAJ06B05-5)

摘　　要：基于可移动的双坡屋面实验房获取的近地面台风风速和房屋表面风压同步实测数据,研究了台风作用下低矮房屋屋面风荷载。研究结果表明:在斜向风作用下,迎风屋面屋脊角部区域、屋面角部区域易形成较高的局部峰值负压并具有较大的脉动风压,风压系数概率分布为非高斯分布。在低频范围内,屋脊角部区域脉动风压预测谱与实测压力谱吻合相对较好;在高频范围内,脉动风压预测谱都低估实测谱。相对良态气候条件,在台风天气条件下,来流气流与建筑物相互作用产生的特征湍流对高频范围脉动风压功率谱影响显著,未考虑竖向风攻角和竖向脉动风速变化相对显著,在屋面角部区域现行规范计算方法相对低估其脉动风荷载。Wind loads on the gable roof of a low rise building were studied using the pressure data and wind velocity data recorded from a full-scale moveable instrumented low-rise building. The results revealed that high local suctions on the ridge in se comer and the eaves corner were observed under oblique flows. parated flow regions were non-Gaussian. The measured pressure Probability distributions of the fluctuating pressure spectra at several locations on the windward ridge corner agreed with the predictions of the quasi-steady theory in low frequencies quite well. However, the predicted spectra decayed significantly faster than the measured pressure spectra in high frequencies. Comparing with those obtained under non-typhoon wind climates, it would appear that building generated or wake turbulences are responsible for the discrepancies from the predictions of the quasi-steady theory. Vertical wind components and pitch angle varied significantly during typhoons, which caused underestimation of fluctuating wind loads.

关 键 词：风荷载 低矮房屋 风压实测 峰值压力 脉动风压谱 

分 类 号：TU312.1[建筑科学—结构工程]