A STUDY ON THE REMOVAL OF SNOW FROM MEMBRANE STRUCTURES

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Publication year 1990
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Title A STUDY ON THE REMOVAL OF SNOW FROM MEMBRANE STRUCTURES
Author Kiyotoshi OHTSUKA,Osamu JOU,Yoshinori HOMMA,Yasuyuki MIYAGAWA,Takashi MASUMO,Hiroshi OKADA
Summary In order to develop an effective system for the artificial removal of snow on the retractable membrane roof of large span structures to be constructed in the snow rich regions. a series of field experiments were made at Sapporo City to collect the basic data on the physical properties of roof snow for melting and sliding. which are required for the optimal design of snow melting equipments and for the determination of roof shapes favorable to snow sliding. In the artificial snow melt experiments. a membrane roofed 1/10 scale model of a real sized doom of 100 meters in radius was introduced to investigate the relationships between the amount of heat supplied to the model roof and the rates of snow melt. As for snow sliding mechanics. static friction coefficients of snow to the roof material. and tensile strengths of fresh snow were investigated. because these two quantities are primarily responsible for snow sliding on the roof surfaces. Furthermore. a simple snow sliding model was developed based on the experimentally derived dependences of friction coefficients and tensile strengths on the physical properties of snow. The snow melt experiments suggest that heat supply of about 300 Wm-2 to the roof are　required to prevent snow from accumulating under heavy snow falls with the return period of 200-years at Sapporo City. The values of friction coefficient and tensile strength obtained in the experiments turned out to be consistent as the values for fresh snow on the membrane roof by comparing the observed pattern of snow slide on the roof of model doom with the calculated one by the snow slide model. We will discuss about the application of the analysis made here to the practical design of real sized membrane roofed doom structures.