Load limit on slab 1

[Geffa]

If a load limit was set to 500kg per square metre on a concrete slab floor of a high rise building on the 11th floor.
A 6 metre beam was fixed to the ceiling concrete slab at 500mm intervals.
A trolley beam was loaded to 1 tonne and the load traversed across the beam.
Is the load to the slab divided into 6 or by two.

Is the slab load limit exceeded by the weight of the beam.

If the fixings from the beam to the slab ceiling were moved to 2 metres the beam properties would increase and the weight increased constraining the dimensions and load allowable on the slab.

If there were persons and equipment on the 12th floor directly above the beam and load would this also increase the load on the slab in that square metre.

 

[Eng16080]

Is the slab load limit exceeded by the weight of the beam.

In lacking an in-depth analysis by a structural engineer, I would assume the answer is yes. I would not assume that the slab has any reserve capacity to resist an additional load which it was never designed for.

If there were persons and equipment on the 12th floor directly above the beam and load would this also increase the load on the slab in that square metre.

If persons and equipment are on the slab, then yes, this will cause an increase in the load on the slab. That seems obvious. Maybe I don't understand the question.

Definitely hire a structural engineer before proceeding with this!

 

[Geffa]

Structural engineers have been employed. This is for my understanding as I think they have made some mistakes and have brought this up but have not got any answers from them.
I install operable wall systems. The operable walls are suspended from beams sometimes with posts at either end of the beam to the concrete floor slab and to the concrete ceiling.
When the system is traversed across the beam the operable wall load can be concentrated into a width of 500mm. The fixings on the 6 metre beam to the slab are a metre apart does is the load between the beam 1 metre fixings to the slab take the weight or is it spread across the all fixings to the slab? If the load is 1.5 tonne and the slab is rated to 450kg a square metre are we not overloading the slab.

 

[human909]

Structural engineers have been employed. This is for my understanding as I think they have made some mistakes and have brought this up but have not go any answers from them.

Engineers are often poor communicators. Try a face to face or zoom meeting as opposed to emails if you really want some good answers.

If the load is 1.5 tonne and the slab is rated to 450kg a square metre are we not overloading the slab.

Most likely not. But there is insufficient information. Several factors are at play here that could make this trolley beam perfectly OK.
-A load limit of 500kg/m2 is a uniform load limit. The point load limit is likely significantly higher.
-A beam with connections every 500mm is likely to act compositely with the slab which could significantly improve the capacity
-Given the above the design is probably ok even if the slab is loaded with 500kg/m2 and had a 1T load on the trolley
-The above scenario is likely highly unlikely and not considered in serviceability conditions.

 

[SWComposites]

So what is the real issue?
Are the structural engineers stating the beams and loads are not acceptable?
Are there failures in the slab?
Are there failures in the connections?
Is there something about the beam or connections specified by the engineers that you don't like?

 

[Tomfh]

A point load of 1 tonne is unlikely to overload a slab designed for 500kg/m².

However, the crane load is "borrowing" load capacity from the floor above. If the floor was rated for 500kg/m² without a 1-tonne crane below, its capacity is now reduced. Only an engineer can determine the extent of this reduction.