Openings on concrete bearing walls

[tonycampos88]

hello,
I have some concrete bearing walls with some large openings. My question is how to design the lintel or header above them. I still have about 3 or 4 feet of wall above the opening. The problem is that sometimes I have some short openings where these 4 ft would cause a deep beam behavior, am I right? or can I pick a depth and reinforce this depth as if this was my beam?
What is the normal approach in these cases?

 

[jayrod12]

I would probably pick a depth, say 2 feet. use that as the lintel calculation, the remaining foot or two feet of concrete above I would consider a dead load.

This may be conservative, it may be considered as wrong (as the additional concrete above will still provide some beam action) however it I think it a reasonable assumption to make. It avoids having to go into strut and tie models for deep beams.

But that's my opinion. At our office we specify 2-15m bars around all openings extending past the opening enough to develop the bars. There's a good chance that reinforcing and the depth of concrete above are more than enough to provide an adequate header above the door.