2 STORY OFFICE BUILDING
2 STORY OFFICE BUILDING
(OP)
I have a 2 story office building (approximately 60'x220') with the floor framing being precast plank and the roof framed with bar joists. The grade along one side (the 220'dimension) is all the way up to the precast. So basically its a walk out basement.
What is the easiest way to account for the unbalanced load from the soil? Would it be the easiest to treat the back wall as a cantilevered retaining wall? Or, try to take the loading out in masonry shear walls? I have limited cmu walls,so this might be tough to do.
Thanks for all your help!
What is the easiest way to account for the unbalanced load from the soil? Would it be the easiest to treat the back wall as a cantilevered retaining wall? Or, try to take the loading out in masonry shear walls? I have limited cmu walls,so this might be tough to do.
Thanks for all your help!






RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
I'm probably going to use a cantilevered retaining wall. Which leads to my next question..
If I treat it as a cantilevered wall does it really act as one? I have cmu walls throughout the building. So is the cantilevered wall going to rotate enough to act as one or will it also act as a simple supported wall? Should I also put reinforcing along the inside face?
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
I guess thats why I ask the question if I can treat it as a cantilever system or a buttress system knowing that in order for it to act in that fashion rotation needs to exist? Or could I treat it as a cantilever but yet reinforce the inside face of the wall knowing it will possible see a partial simple support load until rotation exists?
I hope this makes sense. Thanks for all the help!!!!
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
Thanks again for your help
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
How come it always seems we stick out our necks to save someone else a buck!!! I won't get started on that topic.
Thanks again. The info was greatly appreciated.
RE: 2 STORY OFFICE BUILDING
Put reinforcing steel for your back wall on the inside face, and make sure you put on your drawings everywhere "DO NOT BACKFILL UNTIL FIRST FLOOR FRAMING IS IN PLACE AND SECURE". Therefore, no load reversals. And, depending on the thickness of your walls, you may need reinforcing on both faces. If so, design the reinforcing on the inside face to act as a simple beam, and the reinforcing on the outside face to act as the cantilevered wall. Now you have no problems if the contractor "accidentally" backfills before the first floor is in place.
RE: 2 STORY OFFICE BUILDING
Careful- you have 110 linear feet of load along the top of wall. Could be a very significant shear/l.f. along the connection of hollowcore to the short side walls. Very lage accumlation of total shear.
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
If the wall will be braced at the top or if you can design the precast to act as a diaghphragm, I would design it as a simply supported wall and require it to be shored until conc. has reached 85% of design strength and first floor is completely built. If you cannot get the first floor to fully brace the top of the wall then I would design it as a cantilevered retaining wall. That will generally be your worst case scenario anyway. Usually, if it is a 12" wall, I reinforce both sides anyway and #5@12" each way should take care of any bending on the other side if it develops any simply supported action for a typical basement wall.Also keep in mind the movement of the wall if it is a cantilevered retaining wall. Normally, I would build the wall with a tilt into the soil so it is straight when it is loaded but you need to really analyze this in this situation because your construction above the wall needs to line up with the wall.
RE: 2 STORY OFFICE BUILDING
RE: 2 STORY OFFICE BUILDING
Having the big cantilever footing also helps if at some time in the future a substantial portion of the first floor sog needs to be removed for trenches or other reasons. It gives the owner flexibility. Regards.
RE: 2 STORY OFFICE BUILDING