explain live load

huangyhg

explain live load
i was amazed when a "construction-related" individual was serious when asking, "if your floor framing plan specifies the allowable live load to be 100 psf, and i weigh over 200 pounds, if i should stand in a one square foot area, why do i not go through the floor?"
since he was familiar enough with construction, i was still able to satisfy his curiousity with a technical exlanation.  but, to the client or anyone else who seriously has'nt a clue, in as few words as possible, without any technical, structural jargon, what would be your "simple" explanation?


100 psf is a uniform live load, across the entire floor, that is required by code for certain occupancies.  the code also requires the floor to support a concentrated load equal to 1000 - 2000 pounds or more, depending on the occupancy.
daveatkins
the 100 psf live load describes the (bending and shear)load capacity over the entire floor, not the (bearing or punching) load capacity of the floor under the contact of a person's feet. as a result, a person standing on the floor is supported (in bending and shear) by a much larger area than just the contact area of his feet. the bearing or punching condition is not normally a problem (since the bearing and punching capacity is much, much higher than 100 psf), even for women in high heels, on a concrete floor.
i have heard of a case, where the wheels of a fork truck punched thru a 4" slab. this is the only case where i can think that the punching might be be an issue, but who is crazy enough to drive on a 4" slab, which never was intended for fork trucks?
warehouse managers.