Load distribution for beams reinf. conc. wall

[barnugget]

Can you use a triangluar load distribution for a beam supporting an opening in a reinforced poured concrete wall (M=wl/6)?

 

[14159]

More info is needed if you want intelligent responses:

1. Do you have a lintel cast monolithically with the concrete wall or some other type of beam that's not cast with the wall?

2. What are the proportions of the opening including the amount of monolithic concrete above and to each side of the opening?

3. Do you have concentrated loads within this triangular region?

4. Do you have any joints in the wall near this opening, especially at the corners?

DBD

 

[whyun]

If it is a small opening, monolithically poured, and a deep lintel to justify "arching" effect, it should be acceptable to assume a triangular distribution.

For specifics, I agree with DBDavis.

 

[barnugget]

12' opening for a 6" poured concrete wall reinforced with 6x6 fibermesh. It is a new cut in an existing wall. Only a 1 story concrete building with a concrete joist deck supported by concrete columns exterior and interior. Loads for the roof system are transferred to the vertical columns. The wall has no point loads and is not loadbearing. The load carried is basically 5' of wall above. Thanks for your reply on this. For the load distribution, I'm curious as to whether triangular distribution is viable in this type of setup. I deal mainly with masonry block and am new to renovation of buildings of this type.

 

[DaveAtkins]

The Code does not allow plain concrete except for elements that bear directly on soil. I would use a steel lintel of some sort--perhaps a channel each side of the wall.

DaveAtkins

 

[14159]

1 Harumph for DaveAtkins reply about the channel. You can consider putting the channel one side only if that gets it by your architect.

DBD

 

[miecz]

You could apply the same rules for arching action as for a masonry wall. Those rules however, require the height of wall above the opening to be greater than half the lintel length. If you have 5 ft of concrete above a 12 ft long lintel, you don't meet that criteria.

 

[JAE]

...and adding to jmiec - you also need sufficient wall on either side of the opening to take the lateral thrust of your arching action.

 

[dik]

You can consider a couple of point loads at each side of the opening. If you consider dwls from the beam to the wall, the ones on each side of the opng are likely in tension... just to maintain continuity.

Dik