beam is supported eccentrically on column.

[TRPAM]

Hey everyone
I have this case where the beam is wider then the support.
Normally due to heavy concentrated load on the beam ( transformation beam) there is the potential of shear compression failure.
In order to prevent this type of failure- increasing in the width of the beam will increase its capacity.
The question is: how wide can I make the beam if the beam is not fully connected to the support ?

plus- Can I treat the yellow beam as a cantilever that will support the part that “hangs”?
And do I need to hang the load to the cantilever part ?
If there is any articles regarding this subject I will be glad to read
thank you very much.

 

[BAretired]

The beam running east-west appears to be about three times the width of the supporting wall. That should not be a problem. I assume that "transformation beam" should read "transfer beam" and that the dashed outline near the west end is the heavy load. You will need to check shear stresses. I don't know what shear compression is. Please explain.

The note indicates that the beam shaded yellow is an overhanging beam. Doesn't look like it. It appears to be supported at each end. If it's only supported at the north end, it probably won't work. Is there a slab east and west of the yellow beam?

EDIT: If you're talking about the small overhang at the north end, it's not a problem. The two beams will be poured monolithically together.

BA

 

[r13]

I think the compression shear means punching shear. This question has been raised and discussed recently. IMO, the yellow beam does not support the wider beam, instead, it passes loads to the wider beam, and may causes torsion due to eccentricity with respect to the supporting wall.

 

[TRPAM]

yes, its a transfer beam. and yes the dashed outline is the heavey load.
there is a slab east and west.
the width of the beam is 150 cn and the height is 200 cm.
the shear stress is ok but how can i know that in the vicinity of the suppor,the entire width of the beam will be utilize.
my concern was that at the face of the support, and the shear will "flow" to the more rigid part of the wall ( width of 40 cm)
and for the canteliver part :

 

[r13]

Below is the section cut a few feet east, looking west.

 

[JAE]

TRPAM - try looking at this previous thread (thread507-422472).
It references a couple of outside sources on this and may truly help you.

There is also this document (requires payment):

https://www.icevirtuallibrary.com/doi/10.1680/jstbu.15.00124

Another paper on it:

http://www.i-asem.org/publication_conf/asem13/249.T3D.2.CT224_367F.pdf

Your concerns over the engagement of the wide beam into the support via shear is valid. This "somewhat" follows ACI flat slab design provisions in ACI 318. You might review that.

Finally, ACI 352R deals with beam-column joints and, while primarily focused on narrow beam issues, does deal with wide-beam conditions (do a search for "wide" in the document (Ctrl-F) and you can find these mentions.

http://civilwares.free.fr/ACI/MCP04/352r_02.PDF

 

[r13]

Suggest to provide embedded beam as show on sketch below. You shall provide shear reinforcement on the wide beam, and the embed beam, especially near the rigid supports.

 

[TRPAM]

dosent the force need to be lifted at the face of the suppor (in the part of the beam that is wider then the wall)
like this

 

[r13]

I am not familiar with truss analogy (strut $ tie), but if the "A region" is within the column/wall support, then it should be a compression zone. I am not sure the shear (lift) would occur as the triangle area above the truss is free without restrain. The stress in the support region (node) is quite severe though.