Steel Buildings in Europe

Title Appendix A Worked Example: Wind action on a multi-storey building 10 of 18 3 - 31 3.2.3. Wind on the gable Dimensions: b = 10 m and h = 35 m Several parameters remain the same as for the wind on the long side. 1 Terrain category III: z 0 = 0,30 m z min = 5 m 2 Reference height: z s = 21 m (> z min = 5 m) 3 Orography factor Since the slope of the upwind terrain is less than 3°, c o (z s ) = 1,0 4 Roughness factor: c r ( z s ) = 0,915 5 Turbulence factor: k l = 1,0 6 Turbulence intensity: I v ( z s ) = 0,235 7 Turbulent length scale: L ( z s ) = 75,9 m 8 Background factor   0,607 75,9 1 0,9 10 35 1 1 0,9 1 0,63 0,63 s 2                    L z b h B EN 1991-1-4 § B.2(2) 9 Mean wind velocity at the reference height z s v m ( z s ) = 23,8 m/s 10 Fundamental frequency n 1,x It is estimated by the simplified formula: n 1,x = h d 0,1 n 1,x = 0,1 35 120  = 3,1 Hz 11 Non-dimensional power spectral density function   5 / 3 L s 1,x L s 1,x L s 1,x ( , ) 1 10,2 6,8 ( , ) ( , ) f z n f z n S z n   EN 1991-1-4 § B.1(2)