Reinf. Conc.Wall Design & Load Distribution 1

[otto_eng]

Hi folks,

Do you guys consider smoothed tringular or trapezoidal load distribution , when you have a situation in which the load bearing reinf. conc. wall is loaded nonuniformly? For example there are line loads with different magnitude and there is a beam at one of the edges of the wall and a facade load on the other end etc., the reaction force would be higher at the corners and less at the middle etc.
It just seems like a tedious work to bring all these load down on to the other floors without a smoothed rectangular distribution.. but if the load is smoothed then the axial load would be reduced at the edges so the wall would be design for a less load..
I am curious how you guys tackle with it..

 

[HTURKAK]

Apparently you have FEM modelled the walls and the supporting points are provided with vertical spring supports and horizontal supports. You may run your system and see the difference with approximate analysis.

You may perform approximate analysis assuming elastic distribution of the stresses , ( with famous assumption , plain sections remain plane ).
However this assumption will be more reasonable if the springs are soft enough.
Another assumption could be , dispersion of the load with angle 45 degr or look some old books ( Dr. Fritz Leonhardt, Eduard Mönnig , Vorlesungen über Massivbau_ Teil 2 Sonderfälle der Bemessung im Stahlbetonbau)

Pls provide more info to get better responds.

....

He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48

 

[otto_eng]

My boundary conditions are correct.. I just would like to know if you guys consider the reaction forces based on the smoothed rectangular reaction /axial for the wall design or the triangular one by considering a unit length of the wall ? As you can see the difference is almost 20 percent at the wall edges due to the higher load at the edges .. See below:

 

[jayrod12]

Generally speaking, unless it results in a way overdesigned wall, I'd usually design the area next to the opening for the highest UDL on the wall, plus the point load from the opening header. I'd bet when you add those two together, you get pretty close to the maximum value on your trapezoidal loading scenario.

Provided the reinforcing for that load comes out feeling normal, I just put it everywhere. If it comes out feeling a bit heavy, I'll design the wall for just the UDL, and then provide a dedicated column design at the edge of opening.

 

[otto_eng]

@jayrod12 reinf. comparison for these two options and then the column apporach makes total sense!

 

[CDLD]

At the header, I would design a strip of wall with a width equal to what ACI specifies below.
Design the wall strip for the UDL loads and the concentrated load.