Influence of surrounding boundary walls on the external wind pressure of a low-rise gable - roofed building

Abstract

Low-rise structures are not often subjected to rigorous structural analysis, despite their omnipresence. Estimating wind loads on low buildings is moderately complicated compared to high-rise structures due to the effect of the roughness layer. Therefore, anaccurate modelling sequence is required to obtain reliable results. Recent wind tunnel experiments revealed that the interference of surroundings affects the wind pressure characteristics in contrast to the isolated environment. Compared to large-scale objects, smaller objects have been given relatively less attention. One such example is a boundary wall that obstructs the wind flow, forming a wake behind. This research presents a detailed analysis of the effect of boundary walls on external pressure coefficients of low-rise gable-roofed buildings. Wind tunnel experiments were conducted on 1/50 scaled-down gable-roofed low-rise buildings. It was observed, the mean and peak pressure tend to decrease particularly near the perimeter zones at eaves’ height in the presence of boundary walls. Moreover, a reduction was observed in the intensity of diagonal vortices formed along with oblique wind attacks. Interestingly, the boundary walls not only altered the magnitude of external pressure but also its variation, notably. The wind tunnel results were in good agreement with the performed CFD modelling. There it directs to revise current wind loading standards related to low-rise buildings, considering provisions on shielding effect in the presence of boundary walls.