长沙机场T3航站楼雪荷载数值模拟及取值

持续大量降雪在建筑物屋盖表面造成大量积雪,同时在风雪天气条件下,雪粒会发生复杂的漂移运动,使建筑的屋面会发生风致雪漂移现象,导致屋面局部实际雪荷载值超过设计值。长沙机场T3航站楼为造型较为独特的大跨屋盖结构,通过CFD(computational fluid dynamics)数值模拟方法对屋盖积雪分布进行研究,并分析设计取值。在模拟雪荷载时,采用了较为常用的VOF(volume of fluid)法,通过设定各相的体积分数来模拟其空间分布。数值模拟结果表明,积雪迁移现象对多级屋面的积雪分布产生显著影响,导致雪荷载分布不均匀。进一步结合荷载规范进行雪荷载包络设计,得到大厅区域和指廊区域的雪荷载分布系数。

Numerical simulation of snow loading on Changsha airport terminal 3

Intensive snowfall causes heavy snow load on the roof of buildings. Meanwhile, complex migration of snow particles would occur on surface of roof due to wind, which would cause heavier snow loading on roof than design specification. Changsha airport terminal 3 has a super-large structure with a very complex shape and large-span roof. In this paper, a numerical simulation was carried out on snow loading distribution of its roof and the design value was discussed. Migration of snow particles was simulated by means of Volume of Fluid (VOF) model and volume fractions of both air and snow phase were obtained. Numerical simulation results showed that snow migration has a significant effect on snow distribution of multi-level roofs, resulting in uneven snow load distribution. Moreover, snow load envelope was designed in accordance with the specification and the snow load distribution coefficients of lobby and corridor were obtained, applicable for further structural design.