Question

The diagram below shows a column, which is subject to a design uplift force of 345 kN. It is held down by four (4) Grade 4.6 bolts cast into a concrete foundation. 345 kn Work out what bolt diameter (in mm) is required using the formula: Ft = 0.9fub As YM2 For Grade 4.6 bolts, fub = 400 MPa. The material partial safety factor (YM2) = 1.25. As = bolt tension area required (refer to table below for tension areas of selected bolt sizes). Tension areas of metric bolts (As) Diameter (mm) 12 16 20 22 24 27 30 Tension area (mm2) 84.3 157 245 303 353 469 561

Answer 1

Ang Total uplift force IT = 345 kr By formula, ft og fuz. Ax /m2 0.9 X 400 X Ag 345x103 1-25 As = 1197.9 mm2 Net . Area each bolt. Ab = Ax 300 mm² of 4 from the Areco, select [22 mm given bolt with Tension area 303 mm². Æ CS Scanned with CamScanner