矩形截面高层建筑气动基底扭矩系数均方根值研究  

RMS values of base torsional moment coefficients of tall buildings with square and rectangular cross-sections

作　　者：顾明[1] 张正维[1,2] 全涌[1] 熊勇[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]南通大学建筑工程学院,江苏南通226019

出　　处：《振动与冲击》2011年第10期1-5,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金(50621062;50878159;90715040);上海市浦江人才计划(08PJ1409500)

摘　　要：利用高频天平技术,在4种不同风场中对71种不同几何参数的矩形截面高层建筑刚性模型进行了风洞试验,得到了典型风向角下气动基底扭矩系数均方根值,考察了建筑厚宽比、长细比及建筑所处风场类型对气动基底扭矩系数均方根值的影响。不同厚宽比的矩形建筑的气动扭矩的作用不同,试验结果表明厚宽比对气动基底扭矩系数均方根值的影响很大;长细比不同导致的基底扭矩系数均方根值的差异主要是由模型顶部三维流的比重变化引起的,试验结果显示长细比的影响可以忽略不计;风场类型对基底扭矩系数均方根值的影响强弱随厚宽比的变化而变化。基于试验数据,拟合得到了矩形截面高层建筑的气动基底扭矩系数均方根值的经验公式,并对其进行了误差分析。通过与国内外相关研究成果的比较,验证了该拟合公式的精度与合理性,可以为荷载规范的修订和补充提供很好的参考。71 rigid models of typical square and rectangular tall buildings were tested with high frequency force balance（HFFB） technique in four different simulated wind fields;and their base torsional moment coefficients were obtained accordingly.Effects of parameters,such as,wind field,models＇ aspect ratio and side ratio on the RMS values of the torsional moment coefficients at the base of the structures were then studied.The test results indicated that the effect on the torsional fluctuating forces is changed with the side ratio,and the side ratio has a strong effect on the across-wind fluctuating forces;the influence of models＇ aspect ratio is negligible because the aspect ratio only induces the microvariation of the distribution of the aerodynamic force in the top of the model,and the influence of wind fields varies with different side ratios.New empirical formulas for the standard deviation of the base moment coefficient of torsional wind loads on the tall buildings were fitted by using the nonlinear least-square method,and the errors of the empirical formula were analyzed,they provided technical support for the revision and supplement of the present load codes.Through comparing the present wind tunnel test results with data in literatures,the precision and applicability of the empirical formulas fitted were verified.

关 键 词：矩形高层建筑 风洞试验 气动基底扭矩系数 拟合公式 

分 类 号：TU973.213[建筑科学—结构工程] TU317.1