Estimating peak pressure coefficients for high-rise buildings: LES-based evaluation of Gumbel and XIMIS methods

Abstract

Accurately estimating peak wind pressures is essential for the safe and cost-effective design of high-rise buildings. This study evaluates LES-based peak pressure coefficient predictions for high-rise buildings, using 1-h equivalent full-scale wind tunnel data from Tokyo Polytechnic University as a reference. The research examines the effects of segment durations, number of segments, total EFS durations, and wall-specific error analysis and prediction uncertainties in LES. The Cook-Mayne conversion standardized shorter segments to a 60-min EFS duration but introduced prediction discrepancies, particularly for negative peak pressures. Findings indicate that longer total durations with moderate segment lengths yield reliable maximum pressure predictions, while shorter segment durations are more effective for minimum pressures. Wall-specific analysis reveals greater uncertainties near the ground on side and leeward walls due to recirculation and separation, and at higher elevations on the windward wall from stagnation effects. The XIMIS method yields peak estimates comparable to the Gumbel method, effectively handles limited data. While LES shows strong potential for capturing peak pressures, its accuracy in Gumbel based analysis is sensitive to segment and total simulation durations. In contrast, XIMIS offers consistent results without need for segmentation, making it particularly valuable when data availability is limited.