LES simulations of wind-induced pressure on the floor system underside of elevated buildings

Recent hurricanes have shown that coastal elevated houses are still vulnerable to wind-induced damage, mostly to envelope systems. This paper discusses the performance of elevated houses against hurricane wind loads, particularly wind flow characteristics and the distribution of the peak pressure coefficient (Cp_min) corresponding to the underside of the floor system. Computational fluid dynamics (CFD) analysis was utilized to investigate the effect of interior piers and the wind direction (0°,45°, and 90°) on the distribution and the magnitude of Cp_min. The CFD results show that the distribution of Cp_min and its maximum value are dependent on pier distribution (e.g., pier location and spacing) and wind direction. The distribution of Cp_min for the 90° wind direction is more similar to the 0° wind direction, but the leeward parts of the floor system are exposed to higher negative pressures. The maximum of Cp_min belongs to the 90° wind direction, which occurs at the windward edge and behind the interior pier due to recirculation zones and subsequent vortices. The results of this study indicate that current design standards and provisions need to be updated to include proper design requirements for the floor system, particularly around piers, to help reduce direct/indirect wind-induced damage to elevated houses in coastal areas.