eccentric base plate pullout calc

huangyhg

eccentric base plate pullout calc.
i have an eccentric base plate located at the corner of a pier with uplift that has 5 anchor bolts. these bolts do not follow any pci 4 bolt pattern. does anyone know where to look for formulas or what they do in this situation? as always, many thanks for your ideas!
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if you have fem software available, perhaps you could model it on that.
aci 318-02 appendix d covers embedded anchors and has an adjustment factor for eccentric loading.  i would try that.  seems like the design would be standard procedure if you can get a good handle on the area of the concrete cone or truncated pyramid to use and the eccentricity of the load with respect to the bolt group c.g.
to calculate the ab stress in similar cases i have used:
fs = p/a +/- (mc)/i  and keep the signs straight for the direction of load with i being the moment of inertia for the bolt group.
agree with twich, have designed similar as column reinforcement.  s will vary with the ab locations, but still
p/a-+m/s is a good rule, apply stress reduction if applicable.
best, tincan.