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High Strength Bolts Requiring Full Pretensioning

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     Does anybody have any experiences to share regarding the use of "twist 
     off" bolts for situations where full pretensioning is required?  AISC 
     refers to them as "Alternate Design Bolts" in their High Strength Bolt 
     specifications.  I am particularly interested in their use in 
     slip-critical connections in high seismic zones.
     
     The AISC HSB Specification Commentary indicates "The sheared off 
     splined end merely signifies that at some time the bolt has been 
     subjected to a torque adequate to cause the shearing.  If the 
     fasteners are installed and tensioned in a single continuous 
     operation, they will give a misleading indication to the Inspector 
     that the bolts are properly tightened.  Therefore, the only way to 
     inspect these fasteners with assurance is to observe the job site 
     testing of the fasteners and installation procedure and then monitor 
     the work while in progress to ensure that the specified procedure is 
     routinely followed."  This is consistent with the UBC Special 
     Inspection requirements for high-strength bolting.
     
     Thanx,
     
     Rick Drake, SE
     Fluor Daniel, Irvine