不同断面宽度群体高层建筑的动力干扰效应(第2部分 横风向响应)

Wind-induced dynamic interference effects on different-sized tall buildings(Part II:Across-wind response)

采用本文第1部分所介绍的试验技术和软件分析工具,研究了不同宽度比(Br)的两个和三个建筑物间的横风向动力干扰效应。和顺风向响应分析一样,处于斜列的上游施扰建筑的尾流同样是引起受扰建筑横风向响应增大的主要原因,但试验结果同时也显示,当施扰建筑和受扰建筑处于并列和串列时,也会使受扰结构的横风向响应显著加大。在B、D两类地貌下,和受扰建筑大小一样的两个施扰建筑的干扰因子(IF)会比单个施扰建筑情况分别高出80%和25%。小宽度的上游建筑在低风速时就会产生涡激共振而产生较大的IF值,尤其要指出的是位于(3.1b,0)上的Br=0.5的施扰建筑物在B类地貌下和较低的风速下会产生高达7.09的IF值。粗糙化地貌的高湍流度会对上游施扰建筑尾流的旋涡形成产生一定的抑制作用,故在D类地貌下的IF值要远小于B类地貌情况,但在D类地貌下观察到的IF值仍有1.83。

Based on the techniques described at the author's previous work,systema tical studies of the across-wind dynamic interference effects on two and three tall buildings with different sizes were carried out.The incre ased turbulence intensity in the wakes of the upstream buildings is still the k ey factor to induce the adverse across-wind dy-namic response on the downwind build ing.However,the side-by-side and t andem arranged interfering buildin gs can also produce significant interference e ffects.The results show that two upstream buildings can produce more adverse dynamic effects on the downstream building t han a single upstream building does.Due to the vortices induced resonance,the largest interference factor(IF)of 7.09is found when the upstream bui lding of breadth ratio of 0.5is situated at(3.1b,0)in exposure category B at lower flow v elocity.Generally,for higher turb ulence flow disturbing the organize d vortices and reducing the strength o f the shedding vortices,the IF s measured in exposure category D are much smaller than those of measured in exposure ca tegory B.However,maximum IF is still found to be 1.83in the config uration of three identical buildings in exposure category D.