Numerical Investigations of Snow Load Interference Effects on Multiple Arched Roofs Under Wind–Snow Coupled Actions

Driven by the intensification of climate change, extreme snow events are becoming more frequent, posing significant risks to the safety of arched-roof structures. The combination of strong winds and heavy snowfall will cause localized snowdrifts that may exceed the safety design values in load codes. Such localized snowdrift phenomena even get worse under the action of mutual interference between buildings. To address this critical safety concern, this study employed a multiphase numerical model to evaluate interference effects on snow accumulation characteristics for grouped arched-roof buildings. Initially, the predictive accuracy of the numerical method was confirmed by comparing the results of a wind tunnel test. On the basis of full validation, a comprehensive numerical investigation was conducted to examine the snow redistribution patterns and aerodynamic interference effects among multiple arch-roofed buildings. Through analysis, the interference effect manifests as additional U-shaped snow accumulation on the windward surface of the disturbed arched roof, and specifically exhibits three distinct evolution stages of snow accumulation in relation to building spacing. Under adverse conditions, the disturbed snow load could increase by up to 1.4~1.5 times the fully exposed load, exceeding values specified in most design codes. Therefore, an amplification factor of 1.4 is recommended for the code-calculated fully exposed snow load to appropriately account for building interference effects.