【摘要】 为揭示大跨穹顶结构因下击暴流作用而开洞破坏后屋面风压的变化规律，基于壁面射流模型分析大跨穹顶开洞屋面的内外风压分布。首先，验证了平面壁面射流模型模拟出的下击暴流风场的准确性，并通过风洞试验进一步验证，接着，通过数值模拟研究屋面在不同位置破坏开洞对大跨穹顶结构内外风压分布的影响，并进一步研究屋面负压区不同开洞率和不同矢跨比对结构风压分布的影响。结果表明，屋面的负压区破坏开洞后，屋面风压作用得到降低；与封闭建筑相比，同一区域处开洞率为7.5%的外风压系数最大可降低31.8%;内风压系数的幅值随着开洞率的增大整体有减小的趋势，开洞率为2.5%时内压达到负极大值约为-0.51;屋面内外合风压系数由负值变为正值，大部分幅值明显减小，总体平均降幅约为140%;随着矢跨比的不断减小，屋面内外风压体型系数在不断减小，内风压体型系数的减小速率不断衰减。研究结果可为开洞屋面的大跨穹顶结构的抗风设计提供参考。更多还原

【Abstract】 In order to reveal the variation law of roof wind pressure on a large-span dome structure after opening-hole damage caused by a downburst, the internal and external wind pressure distributions on the opening-hole roof of the large-span dome were analyzed based on the wall jet model. Firstly, the accuracy of the downburst wind field simulated by the plane wall jet model was verified, and further validated by wind tunnel tests. Then, numerical simulations were employed to investigate the impact of opening-holes at different positions on the roof on the internal and external wind pressure distribution of the large-span dome. Furthermore, the influences of different opening-hole ratios and different rise-span ratios in the negative pressure zone of the roof on the wind pressure distribution was were also studied. The results indicate that after the negative pressure area of the roof is damaged with opening-hole, the wind pressure action on the roof is reduced. Compared with an enclosed building, the external wind pressure coefficient in the same area with an opening-hole ratio of 7.5% can be reduced by up to 31.8% at most. The amplitude of the internal wind pressure coefficient generally tends to decrease as the opening ratio increases. When the opening ratio is 2.5%, the internal pressure reaches a negative maximum of approximate-0.51. The combined internal and external wind pressure coefficient changes from negative to positive, and most of the amplitudes are significantly reduced, with an overall average reduction of approximately 140%. As the rise-span ratio decreases, the shape coefficients of the internal and external wind pressure on the roof continue to decrease, and reduction rate of the shape coefficients is attenuating. The research results can provide references for the wind-resistant design of large-span domes with opening-hole roofs.更多还原