Steel Buildings in Europe

Title Appendix A Worked Example: Wind action on a multi-storey building 12 of 18 3 - 33 18 Peak factor 0,607 0,0211 0,0211 3,1     = 0,568 Hz (> 0,08 Hz) 3,59 600) 2 ln(0,568 0,6 600) 2 ln(0,568 p        k EN 1991-1-4 § B.2(3) 19 Structural coefficient for wind on the long side 0,884 1 7 0,235 0,0211 0,607 0,235 1 2 3,59 s d          c c 3.3. Internal pressure coefficients 3.3.1. Normal design situation It is assumed that the doors and windows are shut during severe storms, therefore: c pi = +0,2 and c pi = -0,3 EN 1991-1-4 § 7.2.9(6) If air leakage is uniform around the building, the reference height for the internal pressure is z i = z e . Therefore: q p ( z i ) = q p ( z e ) EN 1991-1-4 § 7.2.9(7) 3.3.2. Accidental design situation The most severe case happens when the opening is located in a zone with the highest value of the external pressure coefficient | c pe |. EN 1991-1-4 § 7.2.9(3)  Windows accidentally open upwind, with wind on the long side. This face is dominant and the area of the openings is equal to 3 times the area of openings in the remaining faces. Therefore: c pi = 0,9 c pe = 0,9 × (+0,8) = 0,72 The peak velocity pressure is maximum at the top of the building: q p ( z i ) = q p ( z e ) = 1,09 kN/m 2 EN 1991-1-4 § 7.2.9(5)  Windows accidentally open downwind, with wind on the long side. This face is dominant and the area of the openings is equal to 3 times the area of openings in the remaining faces. Therefore: c pi = 0,9 c pe = 0,9 × (-1,2) = -1,1 q p ( z i ) = q p ( z e ) = 1,09 kN/m 2