flat slab analysis

[kags]

I am doing a flat slab design first time. I propose to provide column head and drop in the slab. How to consider the drop in the analysis of frame. The Code says that the slab with an width of half the span on either side can be taken as effective width.
But the drop covers only a portion of it. That is the drop is present in the "column strip only".In doing so how to take the drop into account and estimate the section properties for the equivalent frame anlysis?Due to the presence of drop, there will be more -Ve moment near the column and lesser +ve BM in the mid span ( ie. middle strip).

Please explain.

 

[rapt]

Kags,

The middle strip is simply a way of grouping the moments into design strips to make design easy. The is no physical middle strip in the slab which will act differently in analysis to a column strip. The whole slab acts together in transferring the loads to the column. The equivalent frame and column middle strips anr a designers tools to make the analysis and design easier.

If it is a true Drop panel (dimension >= L/6 from the column centre in each direction) it can be included in the analysis. Treat it as a T section over the drop panel zone and a rectangular section between drop panels. In both areas the slab with is as you have defined.

If the Drop Panel is significantly smaller than this, it should be ignored for analysis and flexural design and only included in the calculations for punching shear design.

 

[kags]

Thanks Rapt. Is there any good reference available in the net for the analysis and design of flat slabs?