Study on control of snow load on roof

明确了大型建筑在大雪区屋面雪荷载控制的技术知识。在根据地面雪深估算雪荷载时，采用“一日雪深等于或大于10cm的日平均风速”比采用日本建筑研究院标准的“一、二月平均风速”估算出的雪荷载精度更高。对连日降雪量的风速分析结果证明了这一点。即在一天的雪深等于或大于10cm的日子之后，雪荷载增加。作为估计屋顶积雪形状的技术，通过风洞实验测量了屋顶表面的风降，并进行了验证。利用该技术和粉末风洞实验可以进行高精度的估计。建议在大型建筑中采用控制雪荷载的常规移滑方法。为此，提出了降低屋面与积雪界面抗冻阻力的选材技术。可以用来估计抗冻强度的材料表面的粗糙度和拒水性变得清晰起来。因此，我们得出结论，固结剂的强度受实际附着面积的影响。它验证了屋顶部分积雪的清除，这成为实际建筑物积雪清除情况的问题。这使得作用在每个顶板上的滑动阻力是不同的。在滑动试验的基础上，建立了再现部分除雪的理论。

A technical knowledge for controlling of snow load on roof with a large-scale building in a heavy snow fall regions was made clear. In case of estimating the snow load from the snow depth on ground, it was estimated to high precision by using "the average velocity of wind about the day in equal to or more than 10-cm deep in snow depth of a day" than "the average velocity of wind in January and February" which is used the standard of architectural institute of Japan. There was proved from the result which analyzed wind velocity during several-day snowfall. Namely, the snow load was increases behind the day that there was an equal to or more than 10-cm deep in snow depth of a day.As the technique to estimate a accumulation shape of snow on roof, it measured the descent of wind on roof surface by a wind tunnel experiment, and it verified. It was possible to do high precision estimation by using the technique and the powder wind tunnel experiment.We exhort to control the snow load method of regular removal sliding at large-scale building. Therefore, it made a technique of material selection to reduce the adfreeze resistance interface the roofing and the snow. The roughness and water repellecy of the surface of a material by which the adfreeze strength can be estimated became clear. As for this thing, we conclude that adfreeze strength is influenced by the actual adhesion area.It verified the partial removal of snow on the roof which becomes a problem with the removal situation of the snow at the actual building. It made that the sliding resistance which acts there at each roof part was different clear. It established the theory that reproduces a partial removal of snow based on the result of sliding experiment.