大跨度球壳屋盖风致积雪数值模拟及雪荷载不均匀分布系数研究

Numerical simulation of snow drifting and research on snow uneven distribution coefficient of long-span spherical shell roofs

采用风雪单向耦合方法及单方程雪相模型对大跨度球壳屋盖结构进行风致积雪分析。通过改变风速和矢跨比分别研究屋盖表面积雪和侵蚀沉积量随风速及矢跨比变化的关系。拟合球壳屋盖表面积雪侵蚀量随风速和矢跨比变化的近似公式,建议了球壳屋盖表面雪荷载不均匀分布系数计算式,并与现行建筑结构荷载规范采用的雪荷载不均匀分布系数进行对比。研究结果表明:球壳屋盖表面的积雪侵蚀量与风速呈抛物线关系,与矢跨比呈线性关系;计算得到的球壳屋盖表面的雪荷载不均匀分布系数与ISO国际标准草案规定较为接近。

The snow drifting on long-span spherical shell roofs was simulated by the one-way coupled and singleequation model method. The relation between the erosion or deposition amount and wind velocity,and that between the erosion or deposition amount and the rise-to-span ratio of the roof were studied respectively by changing the wind velocity of the inlet or the rise-to-span ratio only. A fitting formula was suggested to estimate the snow erosion amount according to the wind velocity and rise-to-span ratio of the roof. The uneven distribution coefficient of snow on spherical shell roofs was then derived and compared with those provided by different codes. The results indicate that the snow erosion amount of spherical shell roof varies parabolically with the wind velocity and linearly with the rise-tospan ratio. The uneven distribution coefficient of snow on spherical shell roofs obtained in this paper is relatively close to that provided by the draft regulation of ISO international standards.