某百米级高层隔震结构风致效应研究

Study on wind-induced effect of a 100 m level seismically isolated high-rise structure

现行规范采用静力设计的方法可能对高层隔震结构的风致效应考虑不足,为此深入研究了高层隔震结构抗风设计与风致效应,结合现行规范提出高层隔震结构风致效应分析框架,并针对中国某百米级实际工程隔震结构展开风致效应的分析与评估。结果表明:现行规范采用等效静力的计算方式低估了高层隔震结构实际所受的脉动风作用,通过风荷载时程分析发现,隔震层X、Y向的水平剪力相比风荷载标准值作用分别增加了23.8%和27.7%,但从设计的角度出发,现行规范取1.4的分项系数能满足隔震层抗风稳定性的要求;在10年一遇风荷载作用下,高层隔震结构顶部存在舒适度的问题,最大风振加速度达到16.2 cm·m^(-2),超出规范限值8%;在1年一遇风荷载作用下,高层隔震结构顶部的最大风振加速度达到7.6 cm·m^(-2),其居住舒适性更难以满足,高层隔震结构的舒适度问题在今后的抗风设计中应予以重视;提出的分析框架能较系统和全面地反映高层隔震结构风致效应,可为现行规范提供理论参考依据。

The static design method adopted in the current code may not consider the wind-induced effect of seismically isolated high-rise structure enough.Therefore,the wind resistant design and wind-induced effect of seismically isolated high-rise structure were deeply studied,the wind-induced effect analysis framework of seismically isolated high-rise structure combined with the current code was put forward,and the analysis and evaluation of wind-induced effect for a seismically isolated structure of 100 m level practical engineering was carried out.The results show that the code underestimates the fluctuating wind action on the seismically isolated high-rise structure by using the equivalent static method.Through the time history analysis of wind load,it is found that the horizontal shear force in X and Y directions of the seismic isolation increases by 23.8%and 27.7%respectively compared with the standard value of wind load,but from the point of view of design,the partial coefficient of 1.4 in the current code can meet the requirements of wind resistance stability of the seismic isolation.Under the 10-year wind load,there is a problem of comfort on the top of seismically isolated high-rise structure,and the maximum wind-induced acceleration reaches 16.2 cm·s^(-2),exceeding the limit of the code by 8%.Under the once-in-a-year wind load,the maximum wind-induced acceleration on the top of the seismically isolated high-rise structure reaches 7.6 cm·s^(-2),which is more difficult to meet the living comfort and the comfort of the seismically isolated high-rise structure should be paid attention to in the wind resistance design in the future.The proposed analysis framework can systematically and comprehensively reflect the wind-induced effect of seismically isolated high-rise structures,and can provide a theoretical reference for the current code.