Design Considerations of Side bars for an Inverted Tee Beam

[engr.justehh]

Hi there fellow engineers,

I have a slight problem regarding the design for an inverted tee beam. This beam has a height of more than 900mm
so i have considered it as a deep beam. Using the axis provided, M_x is used to design the top and bottom bars.
Whereas the maximum positive moment is used to design the top bars and the maximum negative moment is used to design
the bottom bars. I have attached a picture for reference.

Here are my questions:
1. For the design of top bars, do i use the b_bot for effective width then H for the effective depth?
2. For the design of bottom bars, do i use the b_top for effective width then H for the effective depth?
3. Correct me if im wrong. I think M_y is used to design the side bars. I assumed that the red ones in the drawing
are the side bars provided to withstand Moment Y. If i were to use the conventional Mu = ∅R_ubd², what
would i use as effective width? H or h? and what would i use as effective depth? b_top or b _bot?
I am aware that there is a provision for the Area of skin reinforcement needed for the beam. I just want to know how
to compute the required steel area for the moment My.

Thanks in advance!

 

[KootK]

1) correct if NA stays in the flange

2) correct if NA stays in the web

3) h and b_bot. At least in lieu of a full biaxial strain compatibility analysis as you would do with a column.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[hokie66]

For effective depth, you need to use "d", which is depth to reinforcement centroid, not total depth "H".

 

[engr.justehh]

Thanks for responding Engrs. KootK and hokie66!