Steel Buildings in Europe

Title Appendix A Worked Example: Wind action on a multi-storey building 14 of 18 3 - 35 0,45 m 1,50 m 3,00 m 10 m 6,00 m A B C D 4,00 m Zone A: c p,net = 2,1 Zone B: c p,net = 1,8 Zone C: c p,net = 1,4 Zone D: c p,net = 1,2 Figure A.5 Pressure coefficients c p,net on the parapet – Gable 3.5. Friction forces 3.5.1. Wind on the long side Total area of the external surfaces parallel to the wind direction: A pa = 2 × 35 × 10 + 120 × 10 = 1900 m 2 Total area of the external surfaces perpendicular to the wind direction: A pe = 2 × 35 × 120 = 8400 m 2 Since A pa < 4 A pe , the friction forces should not be taken into account. EN 1991-1-4 § 5.2(4) 3.5.2. Wind on the gable Total area of the external surfaces parallel to the wind direction: A pa = 2 × 35 × 120 + 120 × 10 = 9600 m 2 Total area of the external surfaces perpendicular to the wind direction: A pe = 2 × 35 × 10 = 700 m 2 Since A pa > 4 A pe , the friction forces should be taken into account. EN 1991-1-4 § 5.2(4) 2 b = 20 m 4 h = 140 m > 2 b The friction forces apply on the part of external surfaces parallel to the wind, located beyond a distance from the upwind edge equal to 20 m. The friction force F fr acts in the wind direction: F fr = c fr q p ( z e ) A fr EN 1991-1-4 § 5.2(3)