API650 Anchor Bolt vs AISC vs ACI

[chrismoore2]

API states, “An allowable tensile stress for anchor bolts and straps equal to 80% of the published minimum yield stress.” (paragraph after equation E.6.2.1.2-2). Currently, the sheet I worked up uses the anchor bolt sizing from AISC, which puts a safety factor of Ω = 2 and uses 75% of the nominal strength of the bolt. Long story short, it’s the difference between an allowable on A307 of 150 MPa (21.75 ksi) for AISC and 200 MPa (28.8 ksi) for the API 650 code. ACI 318 Appendix D, which the civil guys will use, will use a higher allowable (.75*Fu), essentially the AISC without safety factor of 2. So, which allowable do we want to use?

 

[JStephen]

See Section 5.12. Use the API-650 stresses and loads to size the bolts. Note that API-650 seismic loading is based on allowable stress design.