基于双气动弹性模型风洞试验的邻近超高层建筑风致干扰效应

Research on wind-induced interference effect of adjacent super tall buildings based on two-aeroelastic-model wind tunnel test

  • 摘要: 由于超高层建筑通常在城市中心比邻而建,风致干扰效应对邻近建筑的影响不可忽视。针对先前关于风致干扰效应的研究中因较少采用双气动弹性模型进行风洞试验而导致气动弹性效应对风致干扰效应的影响未能充分反映的问题,本文通过双气动弹性模型和一刚性一气动弹性模型风洞试验,系统研究了相邻两座方形超高层建筑顶部横风响应的气动干扰机理。试验覆盖35个干扰位置(每个位置设置18个折减风速Ur),定量揭示了干扰因子(IIF)、气动阻尼比与建筑布局及气动弹性效应的关联规律。结果表明:在正下游串列布置中,Ur=7~8和Ur>14时IIF达1.1~1.3,且下游施扰建筑距离目标建筑越近,IIF越高;并列布置间距大于2倍建筑宽度时,狭缝效应使Ur=8附近IIF升至1.2~1.3,而间距过近使得两个建筑更像一个整体,响应被抑制。斜上游布置中,目标建筑受施扰建筑高速尾涡影响,高折减风速下IIF高达1.6~2.0。值得注意的是,双气动弹性模型和一刚性一气动弹性模型对比风洞试验表明,气动弹性效应使得中高风速下受扰建筑的负气动阻尼绝对值增大,且干扰因子升高,忽略施扰建筑气动弹性效应会使得风致响应的评估结果偏于危险。

     

    Abstract: Due to the close proximity of super high-rise buildings in densely populated urban centers, the significant impact of wind-induced interference on adjacent structures must be taken into consideration. Previous research did not employ two aeroelastic models to investigate the wind-induced interference effect between two adjacent super-tall buildings. As a result, the aeroelastic effect and wind-induced interference effect could not be well reflected. In this paper, based on a series of two-aeroelastic-model wind tunnel tests, the aerodynamic interference effect of the across-wind response of two adjacent square high-rise buildings is studied. The influences of interference location, reduced wind speed (Ur), dynamic characteristics, and model type on the aerodynamic interference factors (IIF) of across-wind acceleration response are analyzed. The wind tunnel tests were conducted at 35 interference locations, with 18 reduced wind speeds tested at each location, and contour maps of the interference factors were obtained. ‌The results show that, in tandem arrangements, IIF reaches 1.1–1.3 at Ur=7–8 and Ur>14, with higher IIF observed when the downstream disturbing building is closer to the target building; in side-by-side arrangements, IIF rises to 1.2–1.3 near Ur=8 due to the narrow gap effect when the spacing exceeds twice the building width, while closer spacing suppresses the response as the two buildings behave as a single entity; in oblique upstream arrangements, the target building is significantly affected by the high-speed wake vortices of the disturbing building, with IIF reaching 1.6–2.0 at high reduced wind speeds.‌ Subsequently, wind tunnel tests are performed on a one-rigid-one-aeroelastic building model at typical interference locations. Upon comparing the results of two kinds of wind tunnel tests, it was found that the aeroelastic effect increases the absolute negative aerodynamic damping of disturbed buildings at medium and high wind speeds, and the interference factor also increases. Neglecting the aerodynamic effect of disturbing buildings can bias the evaluation results of wind-induced response towards danger.

     

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