Wind tunnel test of wind-induced snowdrift on stepped flat roofs during snowfall

Abstract

Snow distribution on a building surface is uneven due to the complicated drift movements of snow grains affected by the wind. Therefore, an accurate estimation of the snow distribution on a building’s roof is essential in protecting its structure. The existing wind tunnel tests of snow distribution on roofs do not consider the influences of falling snow, resulting in deviations between the test results and the actual snow distribution. In this study, a wind tunnel test method considering the snow falling process was proposed to simulate the irregular snow distribution on stepped flat roofs during snowfall. Based on the test data, the variation rule of snow distribution on the stepped flat roof with different test methods and conditions is summarized. (1) The results of the conventional snow erosion test, which neglected the influences of falling snow, deviated from the existing measurement results. (2) The test results of the proposed method with varying wind speeds and grain sizes met the double-linear or triple-linear rule, which conformed to the measurement results. (3) The initial snow significantly influenced the snow distribution on the front of the lower roof on windward side but only slightly affected the snow distribution on the other locations. The research conclusions could provide significant contributions to the actual engineering design.