群体球壳屋盖风荷载干扰效应风洞试验研究  

Wind Tunnel Test Study on Interference Effect of Wind Load on Hemispherical Dome Group

作　　者：沙蔚博 郑德乾 张晓斌 乐金朝[1] 马文勇 Sha Weibo;Zheng Deqian;Zhang Xiaobin;Yue Jinchao;Ma Wenyong(School of Water Conservancy&Environmental Engineering,Zhengzhou University,Zhengzhou 450001,China;School of Civil Engineering,Henan University of Technology,Zhengzhou 450001,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]郑州大学水利与环境学院,郑州450001 [2]河南工业大学土木工程学院,郑州450001 [3]石家庄铁道大学土木工程学院,石家庄050043

出　　处：《天津大学学报（自然科学与工程技术版）》2020年第3期324-330,共7页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51408196)~~

摘　　要：针对大跨球壳屋盖风荷载的干扰效应问题,在大气边界层风洞内分别对单球壳和四球壳屋盖进行了刚性模型测压风洞试验.通过对比分析有、无考虑周边球壳屋盖,从结构基底力和风荷载体型系数分布规律等方面研究了群体球壳屋盖间的干扰效应.结果表明:在风对屋盖结构的整体作用方面,球壳屋盖结构基底平均竖向力系数值为0.81,为向上的风吸力,而基底平均水平力系数值为0.19且主要表现为顺风向的阻力;周边球壳屋盖的存在显著地减弱了结构的基底竖向力,而在部分风向角下增加了结构的基底水平力;在结构的抗风设计中,四球壳屋盖结构的基底水平力干扰因子由于偏安全考虑取为1.21,而基底竖向力可不考虑干扰效应,即结构受到的向上风吸力可按单球壳工况的竖向力取值.在风对屋盖结构表面产生的局部风荷载分布方面,单球壳屋盖结构表面的体型系数呈现对称分布,迎风面低纬度区域存在小范围的正压,其最大体型系数为0.99,而在屋盖顶部高纬度区域则存在较大的风吸力,相应体型系数可达-1.70;周边球壳的存在使得屋盖表面体型系数的分布形式有所改变,其风致干扰主要表现为遮挡效应,即减弱了屋盖表面相应区域的风压(吸)力,但在150°风向角时,周边球壳的干扰却使得屋盖迎风面局部区域的风压力变为风吸力.Rigid model pressure tests on single and four-hemispherical dome structures were conducted in an atmospheric-boundary layer wind tunnel to study the interference effect on a large-span hemispherical dome group.The interference effect was investigated by comparing the base force and wind-load shape coefficient distribution on the dome structure with and without considering the surrounding domes.Results show that,with regard to the wind effect on the entire dome structure,the vertical base force is wind suction in the upward direction with a vertical base force coefficient of 0.81,and the horizontal base force is mainly the drag force in the streamwise direction with a force coefficient of 0.19.Owing to the existence of the surrounding domes,the vertical base force is remarkably reduced,whereas the horizontal base force is increased in several wind directions.In the wind resistance design for the four-hemispherical dome groups,the interference factor for the horizontal base force is suggested to be 1.21 with consideration of the structure safety,whereas the interference effect on the vertical base force is negligible,i.e.,the wind suction can take the value of the vertical base force of the single dome.For the wind-induced local wind load on the roof surface,the wind-load shape coefficient presents a symmetrical distribution on the surface of the singlehemispherical dome.The shape coefficients are positive with a maximum value of 0.99 at a low-latitude region on the windward side of the single-hemispherical dome.These coefficients become negative as a result of wind suction at a high-latitude region on top of the dome,and the corresponding value is up to-1.70.The distribution of the shape coefficient changes when the effects of the surrounding domes are considered.The interference effect is mainly a sheltering effect and the wind pressure(suction)is reduced at most wind directions.However,the wind pressure changes to wind suction at a local region on the windward side of the dome at a wind direction equal to 150°.

关 键 词：球壳屋盖 风洞试验 干扰效应 基底力 体型系数 

分 类 号：TU312.1[建筑科学—结构工程]