Site- and building height-dependent design extreme wind speed vertical profile of tropical cyclone

Abstract

Tropical cyclone (TC) wind is one of the dominant loadings in the design of building structures. The radial distance-dependent vertical profile and prominent jet structure or super gradient of TC winds make the conventional terrain-dependent design profile inadequate for describing TC wind loadings along the height. Herein, a stochastic simulation-based algorithm is developed to determine the design extreme wind speed vertical profile of TC using a quasi-3D TC wind field model. The wind field model is first described and validated by comparing the vertical wind speed profiles with the upper-level dropsonde data and lower-level tower observation results. The evolution of the wind profile during the passage of historical real storms is reproduced by introducing optimal fitting results for the wind field parameters. Ten-thousand-year synthetic tracks are simulated to obtain the design extreme wind speeds for several coastal cities. The design extreme wind speed composite profile and structure height-dependent outer envelope profile (OEP) are proposed, which are applicable to a certain height of interest and buildings with different heights, respectively. These profiles also depend on terrain exposure, return period, and location of the site of interest. The code-suggested profiles are confirmed to underestimate the TC-induced wind loadings along the height, especially at sites with lower roughness lengths. The power law profile is still applicable, but larger power coefficients should be utilized, and the design extreme wind speed at 10m should be increased with an increase in the structure height. This study provides a forward step towards the rational estimation of TC-induced wind loadings for high-rise structures. • The radial distance-dependent vertical profile and prominent jet structure of tropical cyclone winds are reproduced. • The design extreme wind speed composite profile and structure height-dependent outer envelope profile (OEP) for tropical cyclone are proposed. • The inadequacy of current code-suggested wind speed vertical profiles to tropical cyclone winds is discussed. • The design extreme wind speed vertical profiles of tropical cyclone in several coastal cities are developed.