PRACTICAL ESTIMATION FOR UNBALANCED SNOW ACCUMULATIONS ABOUT FLAT AND GABLE ROOFS BASED ON WIND PRESSURE

In estimating the unbalanced snow loads on roofs of buildings in structural design, it is important to consider the influence of wind action on drift of snow accumulation. In our previous papers, based on wind tunnel tests about various shapes of roofs, we have discussed the possibility of estimating snow accumulation patterns by using the characteristics of the gradient of wind pressure distribution from windward to leeward on roof. That is, in the area of negative pressure on roof, snow depth distribution tends to increase to leeward when pressure distribution decrease to leeward, and conversely, the former decreases when the latter increases. On the other hand, in the area of positive pressure on roof, such relationships are reversed. In order to predict snow accumulations for arbitrary inclination of span roofs, we propose a new method to estimate the unbalanced snow distribution coefficients by applying the relationships between the wind pressure coefficients and the unbalanced snow distribution coefficients.