Steel Buildings in Europe

Title Appendix A Worked Example: Wind action on a multi-storey building 4 of 18 3 - 25 3 Basic velocity pressure q b = 422,5 N/m 2 § 4.5(1) 4 Terrain factor k r = 0,215 § 4.3.2(1) 5 Roughness factor § 4.3.2 The total height of the building is: h = 35 m The width of the wall is: b = 10 m h > 2 b Therefore several strips are considered: - The lower strip between 0 and b = 10 m - The upper strip between ( h – b ) = 25 m and h = 35 m Intermediate strips with a height taken equal to: h strip = 5 m The values of c r ( z ) are given in Table A.1. EN 1991-1-4 Figure 7.4 6 Orography factor c o ( z ) = 1,0 EN 1991-1-4 § 4.3.3 7 Turbulence factor k l = 1,0 § 4.4(1) 8 Peak velocity pressure The peak velocity pressure is calculated for each strip, with z = z e which is the position of the top of the strip (see Table A.1). Table A.1 Peak velocity pressure – Wind on the gable z e c r ( z ) v m ( z ) m/s I v ( z ) q p ( z ) kN/m 2 0 10 m 0,75 19,5 0,29 0,72 10 m 15 m 0,84 21,8 0,26 0,84 15 m 20 m 0,90 23,4 0,24 0,92 20 m 25 m 0,95 24,7 0,23 1,00 25 m 35 m 1,02 26,5 0,21 1,09