RCDC is not taking exact value of forces in column design from staad

Dear Sir

We would request you to share the sample file (STAAD and RCDC) and highlight the issue.

RCDC takes exact forces from analysis.

In this staad file for column 5 steel requirement is more then  in rcdc file. please solve the issue8053.file.STD

Dear Sir

You have attached wrong file.. You have to attach .rcdx file. Please close the RCDC file if open on your system, Zip it and attached.

As per snap attached by you, You are comparing shear design from RCDC with flexural design on STAAD.
I would request you to check the flexural design in both the files.

column design.zip

Sorry,  But I have checked its  flexural design in both the files.

Dear Sir

I have checked the STAAD and RCDC file shared by you. There seems minor difference in the forces.
ref: C5 
STAAD File


RCDC file Sent by You,


New RCDC file created by me,


I would request you to compare the RCDC file which is created from same STAAD file. i have attached RCDC file for your reference.RCDC file created by me

Thanks for  sharing the RCDC file but can  you explain me why area of reinforcement provided by staad is more then what is provided in RCDC. for eg: RCDC showing 4-T16 for column 5 but staad is showing more reinforcement provided  i.e 4-T20 

Dear Sir

RCDC is performed the check as per the reinforcement provided in the column. I would request you to check the design calculation report, all load combination reports available in RCDC, if you have any issues in the design please let us know.
the column design in RCDC is based on PM curve.
Clause 39.6 says that interaction equation is to be an alternate solution when assumptions in 39.1 and 39.2 are not followed. refer below snap from IS 456



in RCDC the PM curve along both the axis generated as per Basic strain stress diagram as per clause 39.2 and 39.2. Thus interaction formula is not used in RCDC.

not using interaction diagram might give different results in RCDC and STAAD. However, I would suggest you to follow the results available from RCDC.

Dear Sir

RCDC is performed the check as per the reinforcement provided in the column. I would request you to check the design calculation report, all load combination reports available in RCDC, if you have any issues in the design please let us know.
the column design in RCDC is based on PM curve.
Clause 39.6 says that interaction equation is to be an alternate solution when assumptions in 39.1 and 39.2 are not followed. refer below snap from IS 456



in RCDC the PM curve along both the axis generated as per Basic strain stress diagram as per clause 39.2 and 39.2. Thus interaction formula is not used in RCDC.

not using interaction diagram might give different results in RCDC and STAAD. However, I would suggest you to follow the results available from RCDC.