Applies To | |||
Product(s): | STAAD.Pro | ||
Version(s): | All | ||
Environment: | N/A | ||
Area: | Concrete Design | ||
Subarea: | Interpreting Element Design | ||
Original Author: | Bentley Technical Support Group | ||
How do I interpret the element design results per the ACI code
Here is an explanation on the various design output items reported as part of the analysis output file
corresponding to the DESIGN ELEMENT command.
LONG REINF – Reinforcement required along the longitudinal direction ( along local X axis of the plates ). This reinforcement is reported in terms of area required per unit width of slab
TRANS REINF - Reinforcement required along the transverse direction ( along local Y axis of the plates ). This reinforcement is reported in terms of area required per unit width of slab
MOM-X – Longitudinal moment, corresponding to which LONG. REINF is calculated. This is reported per unit
width of slab.
MOM -Y - Transverse moment, corresponding to which TRANS. REINF is calculated. This is reported per unit
width of slab.
LOAD – Critical load case for each moment
FY – Yield stress of reinforcing steel
FC – Compressive strength of concrete
Cover ( TOP) – Top cover for reinforcement. The surface in the direction of the positive local Z axis of the
plate is considered as top.
Cover ( BOTOM ) - Bottom cover for reinforcement. The surface in the direction of the negative local Z
axis of the plate is considered as bottom.
TH – Thickness of the slab
.
TOP : Longitudinal direction – Only minimum steel required - means that only the minimum amount of reinforcement
as prescribed by the code is good enough for the top surface along the longitudinal direction. All such faces/directions for which minimum steel can be provided,is listed one after another. In the above example, minimum reinforcement is ok for top face in the longitudinal direction and both top and bottom faces in the transverse direction. Only the bottom face in the longitudinal direction needs more than the minimum steel.
The required reinforcements are reported next.
The first 0.54 mm2/mm corresponds to Longitudinal steel at top surface ( comes from minimum reinforcement
criteria )
The 0.00/ 0 data corresponds to ( MOM-X/LOAD ) and indicates that there is zero moment in the longitudinal ( X direction ) at the top face and so no load case is listed as critical.
Next 0.54 mm2/mm corresponds to Transverse steel at top surface ( again comes from minimum reinforcement
criteria )
0.48 /1 indicates that Moment Y ( transverse moment ) for the top surface is 0.48 KN-MM/MM and the
corresponding critical load is load case 1.
Similarly one can interpret the reinforcements for the bottom surface.
These are all required reinforcement areas and based on these one should decide on a suitable bar arrangement ( #
size bars @ xx spacing ). The software does not suggest bar arrangements.