An Experimental Study on Wind Environment caused by Building Group Structure

1. 在大学校园内，利用观测气球测量了城市地区的垂直风速廓线。虽然本次调查的目的是寻找南风和北风的剖面差异，但由于北风条件较差，没有得到充分的结果。计划继续测量。在风洞中采用建筑群模型进行了实验，验证了以下几点：即建筑群密度（建筑覆盖面积和容积率）、布置形式和建筑形状对城区气流和建筑风压系数的影响。结果如下所示。(1)建筑物布置形式对建筑物屋檐高度以下的气流有影响。在建筑物屋檐高度以上，风速在一定高度以上相等，该高度为建筑物屋檐高度的1.5-3倍。街道方向对城区气流的影响可达一定高度。(2)在相同建筑覆盖度下，当建筑物高度增加时，表面边界层厚度和粗糙度参数Z_0总体上随建筑物高度成比例增加。(3)在相同建筑覆盖率下，当建筑物底部长度增加时，当建筑物覆盖率较低时，街道风增大。在屋檐高度以上，风速略有增加。(4)建筑群密度（建筑覆盖）的影响较大，在建筑屋檐高度下，墙体风压差异较大。(5)在考察风压系数在各种建筑形状和排列形式的建筑群条件下重合的标准风速高度时，其高度等于或大于建筑物屋檐高度的5倍。

1. For the grasping approach flow to a urban area, a vertical profile of wind velocity was measured by an observation balloon in the university campus. Although the purpose of this survey was finding the difference of the profile which occurs with the southern approach wind or northern one, sufficient results were not taken because the northern wind condition was poor. The measurement is planned to be continued.2. The experiment in the wind tunnel was conducted using a building group model and it examined following point. That is an influence of the building group density (building coverage and floor area ratio), an arrangement form and a building shape over the urban area air current and a building wind pressure coefficient. The results are shown as follows.(1) An air current below the height of the building eaves was affected by the arrangement form of buildings. Above the height of the building eaves, wind velocity become equal above a certain height, which is 1.5-3 times as high as the height of building eaves. The direction of street influenced the urban area air current up to fairly height.(2) When the building increased in height at the same building coverage, the thickness of surface boundary layer and roughness parameter : Z_0 increased proportionally with the building height in general.(3) When the building bottom length increased in the same building coverage, the growth of street wind was observed in case that the building coverage is low. And a little increase in wind velocity was observed above the height of eaves.(4) The influence of building group density (building coverage) were large and wind pressure on the wall was very different under the height of building eaves.(5) As examining the hight of standard wind velocity in which a wind pressure coefficient coincides on the conditions of the building groups of a various building shape and an arrangement form, its height was equal to or more than 5 times of a building eaves height.