Shielding effects on a tall building from various configurations of surrounding medium-rise buildings

The paper investigates the effect of shielding provided by different configurations of medium-rise buildings surrounding a subject square-section tall building of height-to-breadth ratio at 6. The surrounding buildings are half as tall and represent the existing urban environment in an established Asian city. Mean and dynamic wind loads on the tall building, under shielding from the surrounding buildings are measured in the wind tunnel at different wind incidence angles. Different cases of shielding ranging from two full rows of surrounding buildings on all four sides of the tall building to absence of all surrounding buildings are tested. It is found that the different shielding cases lead to similar degrees of shielding and reductions of mean and dynamic wind loads. In particular, the force measurement results suggest that vortex shedding from the tall building is greatly impaired by the presence of shielding buildings. This leads to a large reduction in the fluctuating levels and coherence of the measured across-wind force excitations on the tall building at normal wind incidence.