Bearing wall close to RC beam

[greznik91]

Hi!

I have a bearing wall (yellow) on top of RC slab. This bearing wall is very close to RC beam that is partly integrated in RC slab (distance between a wall and beam is approx. 0,50 m). bearing wall is supporting another RC slab above so design load on a slab is around 50 kN/m.

I cant move/change geometry - position of walls and columns cant be changed.

Im wondering how load is transfered here?

Since wall on top of a slab is next to a beam, does that mean that this beam can transfer bending moments caused by this wall or not since a wall is not directly above a beam but close to it?

Does that mean that RC slab is mainly in shear because wall is so close to a beam?

I was thinking about designing another beam directly bellow this wall (Id design it as inverted beam partly integrated in RC slab), but Im asking myself how much would this beam actually help? Also this new beam would be supported on beams perpendicular to it which I dont really like. Im not really sure how loads are transfered / how this system acts when a load is close to a beam but not right above it.

Please discuss. Thanks for any help.

 

[KootK]

What's the bearing wall made from? Concrete? CMU? If it's one of those, it'll likely be stiffer than the nearby beam once the wall is set up. Consequently, it might be reasonable to design as follows:

1) wet weight of wall goes to parallel beam.
2) subsequent loads go to perpendicular beams.
3) design both beam and wall to do what you'll be asking of them

I'd definitely like to see the perpendicular beams shear designed this way. Otherwise, you might fail them in shear on the way to developing your presumed load path.

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.

 

[greznik91]

Thanks for your reply . If I understand you correctly - you wouldnt bother with additional (inverted beam) directly bellow a bearing wall?

Bearing wall above a slab is like this:

 

[KootK]

Correct. How tall is this wall and will it have any horizontal reinforcing?

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.

 

[greznik91]

wall is around 3 m tall and is supporting a RC slab above. it has no horizontal reinforcement. One more thing - since wall is full (no opening) should I consider arch effect - which means that majority of load above wall goes directly to supports (in this case to perpendicular beams)?

 

[KootK]

Yeah, with no reinforcing in the wall, I think I'd double up:

1) design parallel beam for 100% load.
2) design perpendicular beam for 100% load.

Both could be reduced with a detailed look at the arching effect but I'd not consider that worth the effort/uncertainty in most applications.

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.

 

[greznik91]

Well thats what I have been thinking about from beginning - to design both beams for 100% load but I thought thats a bit conservative. Since you cant be 100% sure on actual load path in cases like this I think thats the best way to go.

Kootk you helped again. Thanks.

 

[KootK]

Also worth noting that the arching requires thrust resistance at the ends. Not sure you have that hear without wall horizontal reinforcing. Maybe you're getting it some other way.

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.