矩形截面高层建筑横风向等效静风荷载分析

Across-wind Static Equivalent Wind Loads Analysis on Rectangular Tall Buildings

高层建筑横风向风振响应和等效静风荷载备受风工程和结构工程领域的关注。横风向风荷载产生机理复杂,一般认为主要来源于紊流、尾流及旋涡脱落和气动阻尼。横风向风振主要是旋涡脱落下的涡激振动,各国规范大都规定圆柱体横风向涡激振动是确定性振动,非圆截面要依据风洞试验确定。该文综合众多试验研究,提出了在准定常理论不适用情况下的随机振动分析方法,建立了超高层建筑的横风向等效静风荷载的计算模型。引入横风力谱,考虑气动阻尼,对某矩形截面建筑进行了等效静风荷载分析,并对相关参数进行了分析。分析结果表明,按随机振动理论建立计算模型是可行的,当计算横风向风振响应时,应适当考虑正气动阻尼的影响,使计算结果更具真实性。

Both the wind engineering and the civil engineering pay much attention to the across-wind equivalent static wind loads and responses on tall buildings.The formation mechanism of across-wind loads is complex,which is generally caused by turbulent,tail flow and vortex shedding and aerodynamic damping,while across-wind vibration is mainly caused by vortex-induced vibration.Many countries regulate the provisions of the cylinder vortex-induced vibration is deterministic,for non-circular sections which should be based on wind tunnel tests.According to a number of experimental researches,this paper presents a random vibration approach on across-wind equivalent static wind loads and responses while the proposed quasi-steady theory does not apply.With the new method,taking into account the power spectra of across-wind loads and aerodynamic damping,an example is presented and analyzes some parameters.The results show that the random vibration theory is correct and feasible and the results are more authenticity considering aerodynamic damping.