EQUIVALENT STATIC WIND LOADS VS. DATABASE-ASSISTED DESIGN OF TALL BUILDINGS: AN ASSESSMENT
Sejun Park, Emil Simiu, DongHun Yeo
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-an-forth interactions between the wind and the structural engineer required in earlier practices for iterative design. In spite of these advantages, it is desirable to offer structural engineers the option of basing structural design on equivalent static wind loads (ESWLs), rather than on the full time-series used in the DAD approach. Static wind loads are called equivalent if they 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 ESWLs that uses an effective multiple points-in-time (MPIT) method for estimating combined peak wind effects and accounts rigorously and transparently for wind directionality. Case studies were performed by using both the ESWL and DAD procedures, with the latter providing the requisite benchmark results. ESWLs yielded DCIs based on the use of 30 points-in- time significantly closer to the benchmark DAD values than those based on one calculations using one or even four points-in-time (corresponding to 24 wind loading cases). For an isolated building, ESWL-based DCIs approximated to within approximately 10 % the DCIs yielded by DAD. If an adjacent structure affected the oncoming wind flow, ESWLs could underestimate DCIs by almost 20 %. The approximation was also found to be poorer for cases in which a single unfavorable wind direction is strongly dominant. The ESWL procedure is inapplicable to structures with complex shapes. In all cases, the DAD procedure is the safest and most economical and risk- consistent design option.
, Simiu, E.
and Yeo, D.
EQUIVALENT STATIC WIND LOADS VS. DATABASE-ASSISTED DESIGN OF TALL BUILDINGS: AN ASSESSMENT, Engineering Structures, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924579
(Accessed December 1, 2023)