Non-Gaussian characteristics and estimation of extreme wind pressures on roofs of Chinese traditional timber arch corridor bridges

Timber arch corridor bridges, a major traditional Chinese bridge type, possess historical, artistic, and scientific value. Their lightweight long‑span roofs are wind‑sensitive and exhibit pressure characteristics distinct from ordinary structures. To investigate these, wind tunnel tests were performed on a 3D‑printed scale model of Beijian Bridge under varying wind directions and gallery openness. Results show the roof is entirely under suction, with maximum loads at 30° and 150°. Of the peak factors derived from the peak factor method and Hermite polynomial model, 98.96% exceed the code‑recommended value of 2.5, underscoring the need to consider non‑Gaussian characteristics when estimating extreme wind pressures. Gallery openness significantly affects roof pressures: mean pressures and non‑Gaussianity increase from fully open to fully enclosed, suggesting that weatherboards should be removed in high winds to enhance permeability and reduce pressure accumulation. The findings support wind‑resistance evaluation and preventive conservation of such bridge roofs.