摘要
为了研究风雪流对低矮建筑屋盖的作用,制作了6组缩尺模型,在常遇雪天气候下,开展了屋盖积雪特性场地实测与模化分析,考虑了典型的阶梯型屋面以及平屋面、双坡屋面、女儿墙等因素的影响,提出了典型低矮建筑屋盖积雪荷载模化模型。研究表明:阶梯型屋面的积雪分布与已有的场地实测及风洞试验结果相似;平屋面雪荷载沿来流方向呈倒U型分布,可模化为均匀分布,但随着风速变化,积雪漂移使积雪形态可能向倒V型演化,建议考虑其线性非均匀分布对结构的不利影响;风速较低时,双坡屋面的积雪漂移量较少,对迎风侧屋盖更不利,国内外规范均侧重考虑了积雪漂移对背风侧的影响,建议考虑弱风条件下积雪漂移对迎风侧的不利影响;女儿墙的存在使屋面积雪量有较大的增加,屋盖前缘和后缘区域的漂移长度差异较大。结合风洞试验与场地实测,考虑雪粒子与风场的双向耦合、雪粒碰撞、黏结,探索性地对阶梯型屋面的积雪分布进行了二维数值模拟,论证了DEM-CFD风雪流模拟方法的可行性。
Field measurements and numerical simulations were adapted to research snowdrifts on low-rise buildings. Typical roofs including stepped flat roof,flat roof and pitched roof were considered. Snow load models on typical roofs were put forward. The results show that cson stepped flat roof is similar to the existing results,cson flat roof increases along the wind direction,presenting an inverted u-shaped distribution,and can be simplified as an uniform distribution. With the changing of wind speed,cstrends to the evolution of inverted ＂V＂. The adverse effect due to the linear inhomogeneous distribution should be considered. On the pitched roof,the amount of snowdrift is less on the condition of weak wind weather,the adverse effect on the windward side is suggested to be considered. Snow load on the plat roof and the pitched roof both increase due to the existence of parapets,and the drift length on the windward side is much higher than that on the Leeward side. At last,a coupled CFD and DEM method was used to simulate snowdrift on typical stepped flat roof,considering collision and bonding of snow,and the simulation results had a good consistency with the existing field measurement.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第22期225-231,244,共8页
Journal of Vibration and Shock
基金
国家自然科学基金项目(51378428)
西南交通大学青年科技创新项目(SWJTU12CX069)
关键词
风雪流
低矮建筑
屋盖结构
场地实测
数值模拟
规范
snowdrift
low-rise buildings
roof structure
field measurement
numerical simulation
norms
