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Thanks for the replies and opinions everyone. You've pretty much confirmed what I suspected. I've recommended to the Owner that he budget a new floor for the building in his offer to the present owner. There are just too many variables and unknowns on the existing slab and anticipated use. Thanks!!

My client is considering purchasing an existing 25,000 sf shell building. Building was constructed as a shell building by a local municipality. The building upfit was started by a prospective tenant, who then closed down. The building has never been used. The 4" thick floor slab has radiant heat...

I'm evaluating a roof system for a client to place two (2) new HVAC units. The units weigh 600 pounds each, and can be placed near the end of the joist bearing. Joists are spaced at 7 ft centers. I've used SJI to determine that the joists are "186" Open Web Longspan steel joists from Bethlehem...

Girder web crippling calcs get even worse when you recall that there is a 2nd floor column supporting the roof located directly over top the W24 and ground floor column. For reference, the roof joists run perpendicular to the 2nd floor beams.

Agent666: Good point. The beam extends past the column only 12", so the negative moment generated is fairly small, even from the end reaction of the girder connected to it. The W16 beams extend 2/3 the depth of the W24, so they are providing some lateral stability below the CG of the girder, in...

winelandv If it's not composite, then the decking is still welded to the top flange for diaphragm strength. So I'm assuming the top flange is continuously braced by the deck/slab.

Agent666: No, there aren't any drawings available on this building.

Right now the top surface of the concrete, at least in the area of question, looks like a bowl! I had already planned on recommending to the owner that he install web stiffeners at the other column/girder connections. The W24x55 girder fails in bending stress and total deflection under the same...

It's really a 2-fold issue. 1) The girder failed due to web buckling. As you can see there were no web stiffeners where the girder sits atop of the column. Apparently the though the angle clips would be sufficient, or were just not concerned with it. 2) By my calculations, the W16 floor beams...

A client has a 1980's era 2 story warehouse building. The second floor is concrete over 1 1/2" metal decking, 5" total thickness. The floor deckcing is upported by W16x26 beams spaced at 7'-6" oc, spanning 33 feet between W24x55 girders. Girders sit atop W8 columns. The floor was recently...

I will be using RISA 3D to do the structural analysis. This is why I want to use the load with an impact factor (2x, 3x, etc.) I can place the load anywhere on the structure to determine the worst case loading for beams, frames, columns, etc. And can also observe deflection criteria. In...

Thank you all for your responses. Definitely information to consider from all posts.

RobyengIT - I read through these earlier. The concept is to start with static loading, and use that to generate the Impact Factor (IF). I ran numbers on a W14x34 with a static deflection of 0.43". Plugging into the equations, and the IF goes higher and higher the bigger the beam that is...

BAretired - The concept is really no different than when they put scaffold protection over sidewalks during high-rise construction. The crane runs the length of the building (North-South) and there is a defined pedestrian walkway running East-West about 60 feet long. A 5K load with a 3x - 5x...

Well, if a steel beam only 1 foot below the basket won't stop it, then a hard hat 14 feet below will only make a greasy spot on the floor with whoever is under it. This frame is not intended to be loaded like this in normal plant operations. However, if the crane fails, I'm sure the owner will...

Thanks WARose. I just ordered the book.

I'm designing a steel frame to protect employees walking under an overhead crane that carries a basket of steel. The frame I am designing is like a heavy duty canopy. It is 15' x 60' long and 13'-6" tall. It is not supporting any other loads, and will only see a load if the basket being carried...

dnlv: The wall will be constructed using SYmons forms, with forms on both sides, and snap ties through the wall to connect the forms. There is minimal bracing to hold the wall vertical and true. The inner ply will be removed before backfilling, so the outer ply will provide little bracing. We...

SlideRuleEra: Very good questions and points. The application of the floor load (say 250 psf) will exert downward pressure on the soil/stone fill, thereby creating some outward pressure on the wall. With the wall stem now pinned top and bottom by the slab and footing, the wall becomes a simply...

JoelTXCive: I am using the "standard" design from the CRSI Design Guide (2014 Edition). My old 1984 CRSI book has similar dimensions. Running this through RISA Foundation typically produces slightly different results, but I have not done that as of yet. Your point about development is well...