ABSTRACT
The British Standard, BS 6399: Part 2:1995, specifies the wind speed at a particular site as a function of five parameters: the basic wind speed, with factors to provide for altitude, direction, season of the year, and a probability factor. The basic wind velocity varies with geographic location, and the code includes a map of the United Kingdom and Ireland with contours showing basic wind speeds. These contours have minima (or low points) centred about Oxford (20 m/sec), Perth (23 m/sec) and Dublin (23 m/sec), with higher values between and outside these points. There is, for example, a basic wind velocity of about 24 m/sec in a region between the centres and extending down to Land’s End, with about 26 m/ sec along the north-west coast of Scotland, rising to as high as 30 m/sec around the Shetland Islands. Similar maps of wind velocities may be found for other countries and regions and in other sources, but it is of interest here to note that the map for the United Kingdom and Ireland included in British Department of Transport highway bridge code, BD37/88 (Section 4.2), issued in 1988, differs from that in BS 6399. The reason for this is clearly that BS 6399 is later. It reflects more recent work, chiefly by Cook (1982, 1983, 1985) and Cook and Prior (1987), which will be used largely in the following section. The two-volume book, Cook (1985), is a valuable reference. Some other recent works are those by Simiu and Scanlan (1996), Dyrbye and Hansen (1997) and Liu (1991); all deal extensively with the use of probability density distributions in the analysis of wind data. The American Society of Civil Engineers published a state-of-the-art report on wind loading and structural response in 1987.
