Steel Buildings in Europe

Title Worked Example – Fire safety strategies and design approach of steel floor beam 2 of 10 6 - 50 1.2. Applied actions Permanent actions: g k = 3,5 kN/m 2 (self-weight of beam and slab) Variable actions: q k = 3,0 kN/m 2 (imposed loads on the floor) 1.3. Partial safety factors Permanent actions: γ G = 1,35 Variable actions: γ Q = 1,5 Cross-section design at normal temperature: γ M0 = 1,0 Fire design: γ M,fi = 1,0 1.4. Floor system Beam spacing: B = 3,0 m Beam span: L = 7,0 m 2. Verifications for normal temperature 2.1. Actions at normal temperature Characteristic value of actions: w k = 3,5 + 3,0 = 6,50 kN/m 2 Design value of actions: w d = 1,35  3,5 + 1,5  3,0 = 9,23 kN/m 2 Bending moment: M Ed = w d BL 2 /8 = 9,23  3  7 2 /8 = 169,5 kNm Shear force: V Ed = w d BL /2 = 9,23  3  7/2= 96,9 kN 2.2. Resistance at normal temperature 2.2.1. Section classification Based on the geometric properties of an IPE300 and according to the rules given in section 5.5 of EN 1993-1-1, IPE300 is a Class 1 section. EN 1993-1-1, §5.5 2.2.2. Resistance calculation EN 1993-1-1, §6 The concrete floor is assumed to provide full lateral support to the compression flange. Therefore, the lateral–torsional buckling of the beam does not need to be considered. The cross-sectional checks are as follows: Bending moment resistance: M c,Rd = M pl,Rd = M0 pl,y y  W f = 3 3 10 1, 0 275 628 10     =172,7 kNm > 169,5kNm  OK