Field Measurement And Numerical Simulation Of Wind-induced Snow Drift On Typical Roof

The damage of building roof caused by blizzard has always been one of the main natural disasters in snowy areas.The uneven distribution of snow cover caused by wind and snow drift is the main cause of building roof collapse in the snow disaster.However,the snow load is affected by many factors in the natural environment,and its numerical determination has great uncertainty,which brings great challenges to the value of the actual engineering design.Based on the combination of actual measurement and numerical simulation,this paper explores the movement law of wind-induced snow drift and the value of roof snow distribution coefficient from the following aspects:(1)Based on the measured study of the physical characteristics of snow,through the snow density distribution characteristics of snow characteristic analyzer,discusses the snow density under the influence of temperature,the snow depth,parapet,and after the measured determine the average particle diameter of 1.5mm,the average snow density of 150 kg/m~3and the rest of the value range around 60°,provides a reference for the subsequent numerical simulation parameter selection.Finally,the numerical simulation results are verified by using the classical measured case.(2)Simulation of snow drifting of flat roof and high and low roof.The effects of the change of wind field and the change of building geometric parameters on the distribution law of roof snow accumulation is compared through numerical simulation,and the influence of the two on snow distribution coefficient and distribution form are analyzed.The law of the development of flow field and the form of the distribution of friction velocity are determined to infer the feasibility of the distribution of snow cover form,and we summarize the reasons of the change of snow cover distribution from the perspective of wind-induced snow drift mechanism.(3)Simulation of wind-snow drift of double slope and double slope roof with snow slip effect.The influence of wind speed,wind direction Angle,slope and span on the roof snow distribution is summarized.The distribution coefficient of snow cover at the position of multi-span double-slope roof trough is corrected,comparing the calculation method of snow load in the specifications of different countries,comparing the extreme load at different slopes and the values of the reason,it is suggested that the distribution coefficient of snow cover at the trough position is 2.3.