高层建筑间风致扭转干扰效应的试验研究

Experimental study on interference effects of wind-induced torsional responses between two high-rise buildings

为获得不同干扰工况下受扰建筑表面时变风荷载,进行了刚性模型的同步测压试验。对不同折算风速下的扭转响应进行了计算,分析受扰建筑在不同相对位置、不同截面宽度、不同高度的施扰建筑干扰下的基底峰值扭矩响应干扰因子包络值分布规律,并进一步研究了尾流涡激共振机理及其发生条件。结果表明,未发生涡激共振时,峰值扭矩干扰因子包络值最大达到1.9;随着施扰建筑与受扰建筑截面宽度比增大,并列布置时的峡管放大效应越来越显著,峰值扭矩响应最大增加42%。施扰建筑与受扰建筑截面的宽度比为0.4时,施扰建筑旋涡脱落的尾流导致扭转向涡激共振发生,当折算风速达到4.37时,峰值扭转干扰因子包络值达到最大值2.98。随着施扰建筑与受扰建筑的高度比的增加,峰值扭矩干扰因子包络值呈增大趋势。在群体高层建筑抗风设计中,需重点关注施扰建筑高度大于等于受扰建筑高度时的放大干扰效应;对于施扰建筑与受扰建筑截面宽度比较小（0.3~0.5）情况,应避免受扰建筑的折算风速落在3.33~5.56范围内而发生扭转向涡激共振效应。

The time-varying external pressures on the surface of principal building were obtained by applying the synchronous pressure measurement technique. Torsional responses were calculated in different reduced velocities.Distributions of the enveloped interference factor（ EIF） of peak torsional responses for different breadth ratios Br（ Br= Binter/ Bprin） and height ratios Hr（ Hr= Hinter/ Hprin） were analyzed. The interference mechanism and occurrence condition of vortex-induced vibration were further studied. Results show that the maximum value of EIFis 1. 9 in nonresonance cases. The channeling amplification effect becomes more remarkable with increased Brin parallel arrangement,and the peak torsional responses increased by 42%. Vortex-induced vibration phenomenon occurs when Brequals to 0. 4,which is induced by the wake of interfering building,and the maximum value of EIFreaches up to 2.98 as the reduced velocity is 4. 37. Besides,the values of EIFincrease with increased Hr. The amplification effect should be paid attention when Hr≥1. The reduced velocities should be out of the range of 3. 33-5. 56 when Bris from0. 3 to 0. 5,to avoid the occurrence of vortex-induced vibration.