Wind tunnel study of peak wind pressure on government towers in Wanchai during Typhoon York 1999

Abstract

In this paper, we report some wind tunnel testing results of peak wind pressure on the building façade of the three government towers in Wanchai North. The emphasis is on the distributions of peak external wind pressure. A number of regions of amplified peak wind pressure or suction are found on some building faces. Occurrence of these high pressure regions is explained from the strong interference effect on these towers which are placed in close proximity with one another and with other neighbouring buildings. We attempt to correlate these localised regions of high wind pressure or suction to the locations of curtain wall breakage on the towers during the passage of Typhoon York in 1999. In spite of the imperfect correlation and many uncertainties connected with the prediction of actual cladding loads and behaviours during the typhoon, we show that a significant portion of cladding failure is found in regions of high peak wind pressure caused by building interference. It is thus important to assess interference effect and the resulting regions of amplified wind pressure for a safe design of façade cladding.