Existing Slab Footing FAIL when design using STAAD Pro
Existing Slab Footing FAIL when design using STAAD Pro
(OP)
Can anybody help me what i missed?
I modeled an existing mat foundation of heat exchanger using plate element of STAAD Pro.
Slab Thickness is 1100mm reinforced with 28mm dia spaced at 200 center-to-center.
The provided steel is only 3.078sq.mm/mm with Moment cap = 1,131 kn-m/m (existing configuration).
When i modeled this foundation, STAAD computed the Maximum moment to be 1,798 kN-m/m with steel requirement of 5.10 sq.mm/mm which would then create problem because the existing structure fail, and this has been in the field for long time with no problem.
Our goal is to investigate the existing structure to accommodate additional load for a new equipment replacement which is 3.5% heavier than the original weight.
Attached is my STAAD model for reference.
Thank you.
I modeled an existing mat foundation of heat exchanger using plate element of STAAD Pro.
Slab Thickness is 1100mm reinforced with 28mm dia spaced at 200 center-to-center.
The provided steel is only 3.078sq.mm/mm with Moment cap = 1,131 kn-m/m (existing configuration).
When i modeled this foundation, STAAD computed the Maximum moment to be 1,798 kN-m/m with steel requirement of 5.10 sq.mm/mm which would then create problem because the existing structure fail, and this has been in the field for long time with no problem.
Our goal is to investigate the existing structure to accommodate additional load for a new equipment replacement which is 3.5% heavier than the original weight.
Attached is my STAAD model for reference.
Thank you.





RE: Existing Slab Footing FAIL when design using STAAD Pro
I am sure that will guide you towards the results which you are looking for.
You have taken a value of subgrade modulus of 24 MPa/m. whether this parameter was same as originally assumed by engineer who has designed this mat?
STPRA
RE: Existing Slab Footing FAIL when design using STAAD Pro
I think the previous calculation was done manually and no finite element analysis. anyway, thanks for your input STPRA.