Steel Buildings in Europe

Part 3: Actions 3 - 13 8 WIND ACTION 8.1 General The determination of the wind action according to EN 1991-1-4 [4] is described in Single-storey steel buildings. Part 3:– Actions [10] for a single storey building. For a multi-storey building, the calculation is nearly the same, except for two aspects:  The calculation of the structural factor c s c d  For slender buildings, the external pressure coefficients must be calculated for different strips along the height of the building. According to EN 1991-1-4 § 6.2(1), the structural factor may be taken equal to 1 when the height of the building is lower than 15 m, which is commonly the case for single storey buildings. For multi-storey buildings, which are commonly higher than 15 m, the structural factor has to be determined. Section 8.2 provides the main steps of this calculation according to EN 1991-1-4 § 6.3.1(1). A detailed example including the full calculation of the wind action on a multi- storey building is given in Appendix A. 8.2 Structural factor c s c d The structural factor c s c d should be calculated for the main wind directions, using the equation given EN 1991-1-4 § 6.3.1(1), provided that:  The building shape is a rectangular, parallel sided as stated in EN 1991-1-4 § 6.3.1(2) and Figure 6.1  The along-wind vibration in the fundamental mode is significant and the mode shape has a constant sign. This calculation requires the determination of several intermediate parameters.