| Three-center circle structure is usually used in coal storage structure,large span structure such as coal storage is sensitive to the value and distribution of wind and snow load.In recent years,snow disasters result in structural collapse accidents frequently.The current code of our country only gives the snow load value of some simple structure forms,three-center circle roof has unique snow distribution characteristics which are not reflected in the current codes.In this paper,the snow distribution characteristics of three-center circle roof are studied by using the wind-snow combined experiment facility,then the physical properties of the snow particles are measured,and the snowdrift on three-center circle roof is simulated by CFD numerical simulation..The main work and conclusions are as follows:1.The wind-snow combined experiment is carried out by using the artificial snow,the similarity criteria and parameters in the test are determined.The snow distribution test of the three-center circle shell,the rise to span ratio of 1/3 and 1/5 cylindrical shell models under different wind directions and wind speeds is carried out.The results show that under different wind directions,the snow accumulation will occur in the local area due to the influence of wind field,and the uneven snow load will become obvious with the increase of wind direction.The snow distribution law of the three-center circular roof and differences with cylindrical shell roof are summarized.2.The data of snow repose angle under different slopes are obtained by experiment,results show that the snow repose angle is about 60 ° on roof with different slopes,and the angle between snow and roof decreases with the increase of slope.When the slope reaches a certain degree,snow will not accumulate.Based on the measured results,the snow repose angle is set as 60 °,and then a numerical simulation correction method is established in the process of modeling.Compared with the measured results of flat roof and three-center circle shell,it is found that the modified method is in good agreement.The program platform of snow load prediction is established by using MATLAB to analyse a certain structure in the calculation of wind-induced snow drift.3.The snow distribution on the three-center circle roof under different wind speed,wind direction angle and span is simulated.The relationship between the distribution rule of roof snow load and each parameter is summarized.Results show that the wind speed and wind direction have a great influence on the uneven snow load on the roof,the local snow area appears in different positions under different working conditions,and the span mainly affects the snow distribution coefficient in the middle area of the roof.Some technical suggestions were proposed based on research results,which was to perfect the design code for snow loads. |
