基于均匀设计的海峡两岸高层建筑顺风向风荷载多因素分析

Multi-Factor Analysis of Along-wind Loads of High-Rise Buildings Between Chinese Taiwan and Mainland Areas Based on Uniform Design

摘要:

为明确海峡两岸高层建筑顺风向风荷载的异同，对两岸建筑风荷载标准进行了对标分析，并采用均匀设计方法进行了高层建筑顺风向风荷载多因素分析。研究表明：两岸风荷载标准中基本风速取样方法和极值分布参数取值方法存在明显区别，风压高度变化系数分布和不同重现期的设计风速转换系数大致相同，台湾标准给出的湍流强度建议值明显大于大陆标准；台湾标准分类计算建筑物主体和围护结构的设计风压，大陆标准采用统一表达式，两者给出的设计风荷载组合方式区别明显；以基底剪力和基底弯矩作为评价指标，H/BL（高宽比）、α（地面粗糙度指数）、C_g（脉动效应系数）、C_p（风荷载体型系数）和I_z（湍流强度），对高层建筑顺风向风荷载的影响程度依次减小，H/BL和α为主要影响因素；随H/BL的增大，C_g对顺风向风荷载的影响逐渐增强，当H/BL增大到一定程度时，C_g成为主导因素。

Abstract:

In order to determine the difference and similarity of along-wind loads of high-rise buildings between Chinese Taiwan and Chinese mainland areas， benchmarking analysis was used to compare the wind load code for buildings on both sides of the Taiwan strait， and multi-factor analysis of along-wind loads of high-rise buildings was conducted using the uniform design method. The results show that there are significant differences in the basic wind speed sample method and extreme distribution parameter estimation methods. The wind pressure height coefficient distribution and conversion coefficient of design wind speed in different return periods for the two standards are roughly the same； The turbulence intensity values of the Taiwan code is significantly larger than that of the mainland code； For the wind pressure calculation of main wind-force resisting system and cladding， Taiwan wind load code adopts classification method， while the Mainland wind load code adopts a unified expression. There are significant differences between the two standards in the combination of design wind loads of along-wind， cross-wind， and torsional directions. Taking the base shear and base bending moment as evaluation indexes， the influence of aspect ratio H/BL， exposure factor α， gust effect factor C_g， wind load shape coefficient C_p ， and turbulence intensity I_z on the along-wind loads of high-rise buildings gradually decreases， and the aspect ratio and exposure factor are the main influencing factors. The influence of gust effect factor on along-wind load increases with the increase of the aspect ratio of the structure， and when the aspect ratio increases to a certain value， it becomes the main factor that dominates the along-wind loads of the both sides.