福建圆形土楼悬挑屋盖风荷载特性及气动抗风措施研究  

Study on Wind Load Characteristics and Aerodynamic Measures for Wind Resistance of Cantilevered Roofs of Fujian Circular Tulou

作　　者：李玉学 郑千慧[1] 李海云 LI Yuxue;ZHENG Qianhui;LI Haiyun(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province,Shijiazhuang 050043,China;Key Laboratory of Roads and Railway Engineering Safety Control of China Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]河北省风工程与风能利用工程技术创新中心,河北石家庄050043 [3]石家庄铁道大学道路与铁道工程安全保障省部共建教育部重点实验室,河北石家庄050043

出　　处：《防灾减灾工程学报》2024年第2期333-342,共10页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金(51278314,51878040);河北省自然科学基金(E2019210031);中央引导地方科技发展资金项目(206Z5401G)资助。

摘　　要：福建圆形土楼悬挑屋盖属于风敏感结构,且处于我国台风多发区,为提升结构的风灾防御水平,保障其抗风安全,采用CFD数值模拟方法对屋盖表面风荷载分布特性进行研究,同时提出了增强其抗风性能的气动抗风措施。研究表明:圆形土楼悬挑屋盖迎风面风压较大,其中,内、外悬挑屋盖端部风压系数绝对值最大,分别达到1.5和0.75,属于风荷载敏感部位;在外悬挑屋盖端部加设竖直挡风板和波纹挡风板均可以一定程度地卸载上述风荷载敏感部位的风压值,综合比较,设置波纹挡风板较竖直挡风板对风压卸载效果更好;对于设置波纹挡风板,当其相对高度h/Hj=0.05(h为波纹挡风板高度,Hj为地面到屋脊处距离)、倾角θ=-45°、波纹圆弧半径R=5.5 m时整体对屋盖表面风压卸载效果最优,其内、外悬挑屋盖端部风压系数卸载率分别达到40.1%和54%,原因在于倾斜布置的波纹挡风板对悬挑屋盖表面来流起到阻挡作用,使得气流撞击形成的漩涡从屋盖悬挑端转移到挡风板表面,同时波纹的存在降低了内、外悬挑屋盖表面气流漩涡强度,从而达到卸载屋面风荷载的效果。The cantilevered roofs of Fujian circular Tulou are structures that are sensitive to winds,lo-cated in China′s typhoon-prone areas.In order to improve the structures′resistance to wind disasters and ensure its wind-resistant safety,CFD numerical simulation was conducted to study the wind load distribution characteristics on the roofs.Aerodynamic measures to enhance wind resistance were pro-posed.The results showed that wind pressure on the windward side of the roofs was relatively large,and the absolute wind pressure coefficients at the ends of both the inner and outer cantilevered roofs,which were sensitive to wind loads,were the largest,reaching 1.5 and 0.75,respectively.The addi-tion of vertical or corrugated wind deflectors at the ends of the outer cantilevered roofs could mitigate the wind pressure on these sensitive parts to a certain extent.Generally,corrugated wind deflectors had a better effect on unloading wind pressure than their vertical counterpart.For corrugated wind de-flectors,when their relative height h/Hj=0.05(h being the height of the wind deflector and Hj being the distance from the ground to the roof ridge),inclination angleθ=45°,and corrugated arc radius R=5.5 m,the wind pressure unloading effect on the roof surface was the best.The wind pressure co-efficients at the ends of both the inner and outer cantilevered roofs were reduced by 40.1%and 54%,respectively.The corrugated design of the wind deflectors effectively blocked incoming wind flow to the cantilevered roofs,causing vortices formed by air flow impact to shift from the roof ends to the de-flector surface.Furthermore,the corrugations reduced the intensity of air flow vortices on the surfaces of both inner and outer cantilevered roofs,thereby efficiently unloading the wind load.

关 键 词：福建圆形土楼 悬挑屋盖 风荷载特性 抗风措施 卸载机理 

分 类 号：TU312[建筑科学—结构工程]