As an admitted user of ASD for steel design, I don't really understand the
differences between design for slip resistance at the factored-load level vs
at the service load level, other than the obvious difference of whether one
includes load factors or not. (Reference RCSC specification Section 5.4.)
Why must the engineer specify the method to be used by the connection
designer (Section 1.4, item 4)? It would seem that you would simply use the
method corresponding to the type of loads you are designing for, i.e.
factored or unfactored. Is there a real difference in the intended results?
The commentary to Section 5.4 states that these alternatives "have been
calibrated to produce results that are essentially the same.... Irrespective
of the approach, the limit state is based upon the prevention of slip at
service load levels." If the results are essentially the same, why would the
EOR care which method the connection designer uses? If the EOR "does care",
what are the effective differences in results to be expected between the two
William C. Sherman
Camp Dresser & McKee, Inc.