Full Scale Measurment Study for Wind Forces on Rooftiles

掌握作用在屋面瓦上的风力特性，对于包括屋面瓦在内的建筑物的防风性能设计以及防止屋面瓦飞石造成的二次破坏具有重要意义。然而，通过缩尺模型风洞实验来测量作用在屋顶瓦片上的风力并不容易，因为存在着相似律等必须解决的问题。因此，到目前为止，还不能说屋面瓦防风设计的资料已经完全具备。其次，为了丰富屋面防风设计的数据，本研究利用实际尺寸的屋面瓦和一栋建筑物，在自然风作用下，对屋面瓦各面的风压进行了测量。两种典型类型的瓷砖，称为J型和F型，受到。测量的结果考虑了与瓦片位置和风向角有关的风压和风力。因此，以下事情变得清晰。1)各风力系数对J型和F型风向的定性变化相似。2)当风以一定角度吹向屋顶时，瓦会受到强大的升力。3)在作用于瓦片上的风力中，脉动风力占主导地位。4)作用在瓷砖上的外压和内压的风压变量在低频区域具有高相关性，但在高频区域相关性降低。此外，还进行了瓷砖的静载试验，研究了瓷砖顶端的位移与荷载之间的关系。结合以往的风力测量结果，提出了屋面瓦翘起的临界风速。

It is important to grasp wind force characteristics acting on roof tiles because of the windproof performance design of buildings including roof tiles and the prevention of secondary damages caused by flying debris of roof tiles. However, it is not easy to measure the wind force acting on roof tiles by the wind tunnel experiment using scale model, because there are problems which must be solved such as the law of similarity. therefore, it cannot be said that the data for the windproof design of the roof tile are fully ready till present. Then, in this research, in order to enrich the data for the windproof design, wind pressures acting on each side of roof tiles were measured in the natural wind using actual-size tiles and a building. Two typical types of tiles, called J type and F type, were subjected. The result of the measurement was considered about the wind pressure and the wind force related with tile positions and wind angles. Consequently, the following things became clear. 1) The qualitative change of each wind force coefficient to the wind direction of J type and F type is similar. 2) A powerful lift acts on tiles when the wind directs at an angle to a roof. 3) The fluctuating wind force is dominant in the wind force acting on tiles. 4) Although the wind pressure variable of the external pressure and inner pressure acting on a tile has high correlation in a low frequency area, correlation decreases in a high frequency area. Moreover, static loading experiments of tiles were carried out to investigate the relation between the load and the displacement at the tip of a tile. Combining with the previous wind force measurement results, critical wind speed which makes roof tiles lifted was presumed.