grout omitted below baseplates

huangyhg

grout omitted below baseplates
never seen this before.  g.c. decided to leave out 3/4"+- thick non-shrink grout and leveling plates below wide flange column baseplates.  steel frame is fully erected and bearing on concrete supports directly.  sheesh.
gravity forces aren't that substantial (its a one story superstructure) but moment frames were designed to be fixed at col bases so forces on the concrete under the baseplates can be large during a seismic event or wind storm.
on balance, the owner doesn't care if the building is 3/4" shorter and the concrete the baseplates are sitting on is level and generally smooth.  but its not perfectly smooth, as you can probably imagine.
my opinion is that the columns cannot be left as they are, therefore need a remedy to get baseplates to bear uniformly over their entire area per the original design intent.  jacking the columns up and placing grout does not seem feasible (many columns would have to be jacked up all at once, uniformly).  pressure-injecting a low viscocity epoxy under the baseplate might work but there would be no way to verify that the full bearing area was filled in. the cured epoxy also probably wont have as high a modulus as grout.
its a quandary. any suggestions?
you could always just check to see if it works using only the anchor rods as supports (i.e. under moment the anchor bolts on one side take the compression with the other side taking the tension) like many utility pole applications that don't use grout.  if it works this way then it is fine as whatever concrete is in bearing can locally crush under the force until it transfers to the anchor rods.   
preeengineered metal buildings are almost always built as you describe--the base plates sit directly on piers or footings without grout.  there have not been problems with this method of construction, so i don't think you should be concerned about the way this building was put up.
daveatkins
wow, that's a tough one.  what about supporting the columns and cutting a bit off of the bottom.  then you could form up a concrete pedestal and dowel into the footing.  field weld a new base plate to the column and hold the pedestal short leaving more room for a high strength epoxy.  just throwing ideas out there....
how many columns are we talking about?  are they fixed in both x and y directions?
or how about ignoring the existing base plate, and adding two more base plates on either side, grouted as required.  then come up with a gusset detail and weld steel to the side of the columns and then to the new base plates.  that might be fun to design but prob look pretty ugly!  maybe these crazy ideas of mine will help someone brain storm something better!
but dave has a point, what exactly are the requirements for bearing under the base plate in this situation?  and to what willis stated, see page 4-131 in the asd.  you could prob use something like that and design the bolts to take the forces.  adding angles and more bolts if required would be pretty easy.
one problem i see with leaving it as it is:  what's taking the shear?  as the few points of concrete supporting the vertical load under the plate disintegrate during a major seismic or wind event, the only thing taking shear will be the anchor rods.  are you really comfortable with the rods that are in heavy tension also taking a major amount of shear?  i wouldn't be.  you're going to want the friction developed by the grout between the baseplate and the concrete.  run the numbers and it will probably scare you into fixing the problem...
even if the base plates had been grouted, the bolts would be taking the shear (according to the described situation).  also, it sounds to me like willisv is assuming that the base plates aleady have leveling nuts below the plates and that the columns are bearing on the leveling nuts only.  i don't think that samdamon's post indicated the presence of leveling nuts.  it sounds like daveatkins may have best answered the question.
in the past, i have "justified" the omission of grout, as described, by looking at the situation as self-correcting. you may not full contact, but as the loads increase the underlying concrete will "crush" to create sufficient bearing area. even when this happens, the settlement is minimal (a few hundredths of an inch, maybe).
even if you don't agree with this, the risks of doing "something" (and having unintended consequences) have to be weighed against doing "nothing".
in any event, imho, the owner is due a negotiated financial settlement if "nothing" is done.
peinc - yup i was assuming he had backwashers somewhere under there - not a good assumption.  i agree with slideruleera.  
i had a similar situation long ago for a large steel structure in a paper mill's wood yard. the contractor had omitted grouting the grout sleeves, water had collected in the sleeves, then froze, resulting in cracks and some huge spalled-out chunks of concrete (largest being around 100 lbs).
one option suggested was to cut off the lower end of columns and place elastomeric bearings as we used on other equipment in the mill. very expensive. but once it became apparent as to the real cause of the cracking the contractor was brought back, they chipped out the grout under base plates (still had steel shims), put forms around the base plate, drilled into the grout sleeves from side of piers, then pressure grouted with an epoxy grout until pure grout (no air bubbles) came out around the forms, making certain visually that there was full contact with bottom of the base plate. this worked very well as there was 1.5" allowed for grout.
it would be more difficult in your case since there is no grout space under the base plates. but if you are concerned this may be a method to consider.
thanks for all the comments, they are valuable.  fyi there are no leveling nuts under the baseplate. also, i normally don't count on friction under the baseplate to resist shear, just use the anchors.  
no decision yet.  sure wish i got to the site earlier!