Wind impacts on buildings in Hong Kong during super Typhoon Mangkhut

Typhoons, among the most devastating natural hazards, have caused billions in property losses and posed significant threats to human safety globally. Damage to urban structures, particularly building windows, constitutes a major component of direct losses caused by typhoons. This study investigates wind impacts on buildings using large-eddy simulations (LES) in three neighbourhoods where window shattering occurred in Hong Kong during Typhoon Mangkhut. The focus is on three buildings among which two had shattered window glass multiple times in the past years during typhoons. It is commonly believed that wind pressure exceeding a threshold for window breakage is the primary cause. However, our results indicate that the maximum pressure on target walls where window breakage occurred can only reach up to −1.90 kPa, which does not exceed the threshold of the Hong Kong standard for curtain walls set at −2.86 kPa. The maximum pressure in the neighborhood can reach up to −5.47 kPa, occurring in regions of high wind speed downstream of the tallest buildings, where the Venturi effect and downwash effect combine. Although the wind speed and pressure are not as high as expected, the turbulence kinetic energy is extremely high. Therefore, designing curtain walls may need to consider wind speed, pressure, and turbulence to ensure structural resilience and safety.