Reinforced Concrete Footing Design using RCDC CONNECT Edition V9 Update 4

Dear Bentley,

We have been trying to validate RC footing design as per IS 456:2000 using RCDC to use in a MEGA project.

While checking we found following issues:-

1 RCDC assumes the support reactions from STAAD CONNECT Edition to act at footing bottom instead of pedestal bottom. This issue leads to underestimate the forces.
2 RCDC assumes 16mm diameter of rebar for calculation of effective depth. This issue leads to a difference in effective depth calculation.
3 RCDC always by default provide top reinforcement in both directions as follows;
a) 50% of minimum reinforcement (i.e. 0.06%) for footing depths less than 1.0m
b) 100% of minimum reinforcement (i.e. 0.12%) for footing depths greater than 1.0m
If design doesn't require taking care the overall section minimum rebar as per code, this will lead to conservative results.
4 Even when RCDC options ‘Use Gross SBC’ & ‘Consider overburden’ are selected, the software neglects downward weight calculation in design This issue leads to increase in design force & area of steel leading to uneconomical footing sizes.
5 Eventhough ‘Average Pressure’ input is selected for footing , RCDC considers maximum uniform pressure in both direction through out the footing instead average as per actual. This will lead to higher values of the design moment and shear at critical locations.
6 For isolated footing with depth greater than 1m, software does not automatically calculate the required side face reinforcement as per IS 456:2000 Clause 34.5 Side face rebar is required as per code

Kindly help me understand if the issues stated above are valid & if yes, when these issues can be resolved?



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