Investigation and analysis of damages to typical buildings and agricultural greenhouse structures caused by typhoon Kajiki

Typhoon Kajiki (No. 2513) struck Sanya City, Hainan Province, with wind intensity reaching Beaufort scale 14, making it the strongest typhoon recorded in the region. Through field investigations within the typhoon’s 12-level wind circle and an analysis of meteorological data to determine wind speed return periods, a systematic analysis was conducted on the wind-induced damage patterns and mechanisms of three typical structural types: rooftop photovoltaic (PV) arrays, high-rise building envelopes, and agricultural greenhouses. The results show that the wind speed return period in the affected area was slightly below the 50-year benchmark. Consequently, the resulting wind pressure did not exceed the design specifications for general building structures, and thus did not result in significant failure of primary structural systems. However, the investigation also found that some secondary structural elements sustained damage. The specific causes are as follows: damage to rooftop PV structures was chiefly caused by the failure of connection bolts. For high-rise building envelopes, damage primarily resulted from localized excessive negative pressure, fatigue due to fluctuating wind loads, environmental degradation of material durability, and inherent deficiencies in material performance. Damage to agricultural greenhouse structures was mainly due to the aging of covering films, which reduced their tear and wind uplift resistance, alongside insufficient overall structural stability and stiffness. Based on these damage mechanisms, wind resistance and disaster mitigation measures are proposed, addressing five key aspects: design, materials, detailing, construction, and operation maintenance. This study is expected to provide a scientific basis for disaster management decisions by meteorological, construction, and emergency management agencies, as well as for the typhoon-resistant design of engineering structures.