Park Sejun, Simiu Emil, Yeo DongHun
NIST Director's Postdoctoral Research Associate, Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
NIST Fellow, Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
Eng Struct. 2019;186. doi: 10.1016/j.engstruct.2019.02.021.
Recent developments in pressure measurement technology, and unprecedented "big data" capabilities, have enabled the development of Database-assisted Design (DAD), a powerful innovative approach to the design of tall buildings for wind. DAD is accurate, rigorous, transparent, and user-friendly. Also, DAD eliminates unwieldy back-and-forth interactions between the wind and the structural engineer, needed in traditional practices if iterative designs are performed. In spite of these advantages, some structural engineers have shown interest in an alternative approach that uses equivalent static wind loads (ESWLs) in lieu of DAD. Such an approach is warranted if ESWLs induce in structural members demand-to-capacity indexes (DCIs) approximately equal to their peak counterparts obtained by DAD. This paper presents and assesses a simple procedure for calculating such ESWLs. The procedure uses an effective multiple points-in-time (MPIT) method for estimating combined peak wind effects, and accounts rigorously and transparently for wind directionality. A case study is presented that uses both the ESWL and DAD procedures, with the latter providing the requisite benchmark results. DCIs obtained from ESWLs based on the use of ten points-in-time (corresponding to 60 wind loading cases) were significantly closer to the benchmark DAD values than their counterparts based on the use of, e.g., four points-in-time (corresponding to 24 wind loading cases). For the building considered in this case study, ESWL-based design DCIs approximated to within approximately 3 % the DCIs yielded by DAD. The approximation was found to be poorer for cases in which a single unfavorable wind direction is strongly dominant. The ESWL procedure is generally inapplicable to structures with complex shapes. In all cases, the DAD procedure is the safest and most risk-consistent design option.
压力测量技术的最新进展以及前所未有的“大数据”能力，推动了数据库辅助设计（DAD）的发展，这是一种用于高层建筑风设计的强大创新方法。DAD准确、严谨、透明且用户友好。此外，DAD消除了传统做法中如果进行迭代设计时风工程师和结构工程师之间繁琐的来回交互。尽管有这些优点，但一些结构工程师对使用等效静力风荷载（ESWL）代替DAD的替代方法表现出兴趣。如果ESWL在结构构件中产生的需求与能力指标（DCI）近似等于通过DAD获得的峰值对应指标，则这种方法是合理的。本文提出并评估了一种计算此类ESWL的简单程序。该程序使用有效的多点时间（MPIT）方法来估计组合峰值风效应，并严格且透明地考虑风向性。给出了一个案例研究，该研究同时使用了ESWL和DAD程序，后者提供了必要的基准结果。基于使用十个时间点（对应60个风荷载工况）获得的ESWL的DCI比基于使用例如四个时间点（对应24个风荷载工况）获得的DCI更接近基准DAD值。对于本案例研究中考虑的建筑物，基于ESWL的设计DCI近似在DAD产生的DCI的约3%以内。对于单一不利风向占主导的情况，发现这种近似较差。ESWL程序通常不适用于形状复杂的结构。在所有情况下，DAD程序是最安全且风险最一致的设计选项。
