Disaster #4 In RSA RC Column Design According To ACI 318-11 (RC Modulus)

[mustafahesenow]

Hi All,

Here is another problem 

sway column 600x600  with 8m height Reinforcement 4T32 at each side and  Cover to center of  longitudinal reinforcement 50mm The design for one directional bending My No Mz..

A- Calculation of Slenderness effect at Column ENd.

1-RSA calculate only the moment end magnification factor by using Q index of the story which is limited t be used for only when Delta s <= 1.5 as per ACI 10-20 which is mean that Q should be less or equal 0.33   . RSA only highlight this value input for Q larger than 0.33 by yellow color and doesn't give the other option to calculate the Delta s as per ACI  (10-21).

2- Beta d for sway frame is ration of sustained shear on the story which is in the normal building is equal to zero see the 2nd picture attached from ACI code . where RSA still considering it as 1 

This beta d should be editable in order to fix this problem for sway frame .

3-RSA doesn't consider the end moment coming from the lateral force whether using simple cases for loads or Designed load and he always consider it as zero which is mean there is no magnification for end moment for sway frame 

Here attached 2 cases one as design load :

simple cases Gravity and lateral :

B-Calculate the slenderness effect along the length for the sway frame :

RSA Doesn't Calculate the slenderness effect along the length for the sway frame as per Code and doesn't show any calculation to it which is mean the programmer doesn't understand the procedure at all.

See the code requirement attached 

AS conclusion RSA Team have to review the design procedure of the Columns using ACI code and to correct it for all versions this is really disaster and should be fixed immediately and I am ready to help for that.

File is attached .

[Artur.Kosakowski]

Hi Mustafa,

I have forwarded this message too.

[mustafahesenow]

Hi @Artur.Kosakowski

Any update Related to this mistake ? 

[Artur.Kosakowski]

Hi @mustafahesenow

I'm sorry I have no additional information . The moment I have anything I will update this post.

[mustafahesenow]

Hi @Artur.Kosakowski 

This is not a small mistake and its really need to be corrected as possible.

Hundreds of users are using ACI code for design RC elements.

This information have been sent to the forum and to RSA leaders as well  not Only for record its sent for correction .

This post almost one and half month.

So please this need at least confirmation what the status for this problem and when is going to be corrected .

Save Our RSA.

[Artur.Kosakowski]

Hi @mustafahesenow

I'd like to thank you for helping us to resolve this program behavior in the Update 1 for RSA 2019 .

Will you be OK to mark this post as the solution now?

[mustafahesenow]

Hi @Artur.Kosakowski

To be precise for sway column Calculation according ACI 2011 . The Robot Calculation is still not yet corrected 100% and Still have major problems for calculation of such this columns (sway) Please see attached pictures which are extracted From RSA 2019 with Update 1 and compare it to my original post you will see the problem still exist.

In addition to that :

RSA 2019 Still not calculated the slenderness along the length For sway column shown on my original post.

and The limit of maximum magnified moment shall not be exceed 1.4 X original moment is still not exist .