考虑下垫面复杂性的行人风环境评估

为解决城市下垫面给风环境评估带来的困难,建立地形-建筑物耦合模型进行风洞试验,研究某桥址区风环境变化规律;采用三参数Weibull分布对实际下垫面影响下气象数据进行拟合;结合拟合参数和试验风速比得到桥面行人舒适度超越阈值概率.结果表明:桥址区风速受山体的阻挡作用而减小,同时桥址区风速受城市建筑拖曳作用和街道风加速效应明显;结合三参数Weibull分布拟合得到的参数,桥面两端行人舒适度较高,同时桥面跨中位置处受街道风影响较大,易产生行人不舒适感.

Evaluation of Pedestrian Wind Environment on Considering Underlying Surface Complexity

In order to solve the difficulties of wind environment assessment caused by urban underlying surface, to establish terrain-building coupling model for wind tunnel test, and to study the wind environment of a bridge site, 3-parameter Weibull distribution is used to fit the meteorological data under the actual influence of the underlying surface. Combining with the fitting parameters and test wind speed ratio, the threshold exceedance probability of pedestrian comfort on the bridge deck is obtained. The results show that the wind speed in the bridge site is reduced by the blocking effect of mountains, and the wind speed in the bridge site is obviously affected by the drag effect of urban buildings and the acceleration effect of street wind. Combining with the parameters fitted by 3-parameter Weibull distribution, the pedestrian comfort at both ends of the bridge deck is high, the mid-span of the bridge deck is affected by the street wind, which is easy to cause uncomfortable feeling for pedestrians.