大型冷却塔设计风荷载取值研究

Research on Design Wind Loads Values for Large Cooling Towers

我国冷却塔建设日趋高大化(塔高远超规范限制165 m)和复杂化(群塔组合复杂多变、周边建筑干扰显著),相应的设计规范和设计经验已无法满足其抗风设计需求。课题组以国内多个(超)大型冷却塔实际工程为例,进行了考虑群塔和周边建筑影响的刚体测压风洞试验,基于试验结果总结归纳了群塔放大系数取值的变化规律;再加载风洞风压时程进行随机有限元分析,计算获得多个典型高度和塔型的冷却塔结构二维风振系数取值,探讨了塔高、群塔干扰和阻尼比等参数对风振系数取值的影响规律。相关结论可为此类超大型冷却塔的设计风荷载取值提供科学参考依据。

The construction of cooling tower is increasingly enlarged(the height of tower is above the specification limit of 165 m) and complicated(the combination of towers iscomplex and the interferenceeffects of surrounding buildings is significant) in China.The corresponding design specification and design experience have not been able to meet the design requirements. Our research group takes the actual project of several large cooling towers in China as an example, the rigid wind tunnel test considering the influence of group towers and surrounding buildings were carried out. The change rule of amplification coefficient of group tower were summarizing based on test results. The stochastic finite element analysis of the wind pressure time history of the wind tunnel was carried out, and the two dimensional wind vibration coefficients were obtained. On the basis, the effects of the height of tower cranes interference and damping ratio parameters on the wind vibration coefficient were discussed. The main conclusionof this paper can provide scientific reference for the design of super large cooling tower.