高层建筑群静力干扰效应的试验研究

采用力天平技术 ,用风洞试验方法研究了 5种不同高度和宽度比的一个和两个施扰建筑物在不同间距和地貌条件下对受扰建筑的静力干扰影响。分析中采用神经网络、统计分析等方法对不同影响因素进行分析和对比 ,采用了一种比较简洁的方式 ,描述三个建筑物间的风致干扰特性 ,解决了三个建筑物的静力干扰效应难以表示的难点。结果显示 :对于顺风向静力干扰而言 ,干扰因子基本都小于 1,呈现遮挡效应。但同时也发现 ,由于狭管效应 ,处于并列布置时的某些配置的最大干扰因子值可高达 1 2 ,即此时结构在受扰后的平均荷载有可能比其孤立状态增加 2 0 %。一般情况下 ,遮挡效应随施扰建筑物的宽度的增大而增大 ,但狭管效应也会随之增强。高度比小于 0 5的施扰建筑的影响可以忽略不计 ,对干扰效应有较明显影响的高度比在 0 5～ 1 0之间 ,高度比超过此范围的建筑物的遮挡影响基本和高度比为 1的一致 ,但狭管效应则会更为明显。

EXPERIMENTAL INVESTIGATIONS ON STATIC INTERFERENCE EFFECTS OF TALL BUILDINGS

The static interference effect of tall buildings with various heights and breadths in various upstream terrains as well as various spacing was studied by wind tunnel test and force balance technique.The artificial neural networks method and statistical method were used for analyzing and comparing the huge amount of test data.The results show that the upstream buildings generally cause certain shielding effect by decreasing the wind load on the downstream principal building,but side-by-side arranged interfering buildings could significantly enhance the wind load on the principal building owing to the channeling effect.Generally,the shielding effect increases with the breadth of the interfering buildings,but the channeling effect will also increase with the breadth.The effect of the lower interfering buildings with height ratio( H r)less than 0.5 could be neglected,and the sensitive H r is in the range from 0.5 to 1.0.The shielding effect for higher interfering buildings of H r>1 is identical with that of H r=1,but the channeling effect may become more obvious.