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# Civil Engineering/slab panels

Question

panel query
QUESTION: sir,
I have the following queries about how to consider a panel in a solid slab.
1.i believe that if it is a two way solid slab, obviously supported by for beams on the four edges , then it must be considered a panel. is it compulsory for it to be considered as a panel for the beams to be supported by columns on the four corners ?

2.in the attached picture, if you look at the picture at top it is a simple example of a panel., but the bottom picture as you can see has a beam in the middle and obviously the beam is not supported by columns at the ends. now how to consider a panel in the bottom..?

please explain the above queries sir.

1. For top image, if the L:B ratio is much more than 2, you can design the slab as 1-way spanning in the shorter span direction.

2. For bottom image, the slab can be considered as 2 panels, with continuity across the middle beam and discontinuity along the outer beams. With such proportions (almost 1:1), both panels can be designed as 2-way spanning

These comments apply to a solid homogeneous slabs. If you have ribbed slabs or Hollow core slabs, then they are always 1-way spanning.

---------- FOLLOW-UP ----------

QUESTION: sir,
thanks for your answer, do you mean while considering a panel for two way slab , we need to just ensure that slab is supported by four beams and not required to support those four beams by four columns or may be three columns. is it not necessary for the slab to supported by beams and then the beams to supported by columns on four corners...is column support to beams not a criteria while forming a panel? please explain.

Hi Arsalan,

1. Yes, but you could still design it as 1-way spanning if you use a ribbed slab or HC slab.

2. Yes, they can- the middle beam does not need to be supported on columns; so long as the main beams are stiff/strong enough to support the middle beam without too much deflection you can design the 2 panels as 2-way spanning.

Civil Engineering

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