D1.F.3.1 ACI 318-2011 Design Parameters
Parameter Name | Default Value | Description |
---|---|---|
ALPHA | 1.5 for rectangular sections, 2.0 for square sections | Exponent for Bresler Load Contour Method for Bixaial Interaction. |
BDY | 1.0 | Column stiffness reduction factor for bending about the local Y axis. |
BDZ | 1.0 | Column stiffness reduction factor for bending about the local Z axis. |
CLB |
1.5 in. (38 mm) for beams* 0.75 in. (19 mm) for plate elements* |
Minimum cover from the base of
the section to the bottom longitudinal reinforcement.
See Note c below. |
CLS | 1.5 in. (38 mm)* | Minimum cover from the sides of the section to the side longitudinal reinforcement. |
CLT |
1.5 in. (38 mm) for beams* 0.75 in. (19 mm) for plate elements* |
Minimum cover from the top of the
section to the top longitudinal reinforcement.
See Note c below. |
DEPTH | YD* | Depth of the member measured in the local Y axis. |
EFACE | 0.0* |
Face of support location at end of beam. If specified, the shear force at end is computed at a distance of EFACE + d from the end joint of the member. |
FC | 4,000 psi (28 N/mm2)* | Compressive strength of concrete. |
FYMAIN | 60,000 psi (420 N/mm2)* | Yield stress for main longitudinal reinforcing steel. |
FYSEC | 60,000 psi (420 N/mm2)* | Yield stress for transverse reinforcing steel. |
LWF | 1.0 | Modification factor, λ, for lightweight concrete as specified in ACI i318-08, cl. 8.6.1. Valid entries are between 0.75 and 1.0, inclusive. Used as a reduction factor for the mechanical properties of lightweight concrete. |
MAXMAIN | #18 bar (57 mm) |
Maximum size of reinforcing bar to be used for longitudinal reinforcement. |
MINMAIN | #4 bar (13 mm) |
Minimum size of reinforcing bar to be used for longitudinal reinforcement. |
MINSEC | #4 bar (13 mm) |
Minimum size of reinforcing bar to be used for transverse reinforcement. |
MMAG | 1.0 | Factor to magnify the analysis moments used for column design. |
NSECTION | 12 |
Number of equally spaced sections to be considered in finding critical moments for beam design. The valid range is from 12 to 20. This parameter applies to the design process rather than individual members and thus should not have any assigned member list. If more than one NSECTION parameter is defined, then highest value will be used. |
REINF | 0 |
Column transverse reinforcement type.
|
RHOMIN | 0.01 | Minimum reinforcement required in a concrete column. Enter a value between 0.0 and 0.08, where 0.08 = 8% reinforcement; the maximum allowed by the ACI code. |
SFACE | 0.0* |
Face of support location at start of beam. If specified, the shear force at start is computed at a distance of SFACE + d from the start joint of the member. |
SKY | 1.0 | Effective length factor for moment magnification procedure calculations for columns, in the local Y direction. When the SWY parameter is 0 (i.e., not braced), then SKY ≥ 1.0. When SWY is 1 (i.e., braced), then 0.5 ≤ SKY ≤ 1.0. |
SKZ | 1.0 | Effective length factor for moment magnification procedure calculations for columns, in the local Z direction. When the SWY parameter is 0 (i.e., not braced), then SKZ ≥ 1.0. When SWY is 1 (i.e., braced), then 0.5 ≤ SKZ ≤ 1.0. |
SLY | n/a |
Number of the load case that applies sidesway load in the local Y axis for column design. The moments from this case are used to magnify the local Y axis moments for all design load cases as per the sway or non sway requirements. Calculations are dependent on the SWY parameter setting. |
SLZ | n/a |
Number of the load case that applies sidesway load in the local z axis for column design. The moments from this case are used to magnify the local Z axis moments for all design load cases as per the sway or non sway requirements. Calculations are dependent on the SWY parameter setting. |
SQY | 0.2 |
Stability index, Q, in the local Y axis as defined in ACI 318 section 6.6.4.3(b). |
SQZ | 0.2 |
Stability index, Q, in the local Z axis as defined in ACI 318 section 6.6.4.3(b). |
SWY | 0 |
Braced against sidesway:
|
TRACK | 0.0 |
Specify the level of detail in the output:
|
TRN | 0 |
Transverse loads between supports
|
WIDTH | ZD* | Width of the member measured in the local Z axis. |
Notes
- The value used when specifying the CLS parameter for column design is taken to be the clear cover for the longitudinal bars in a column. It is not taken as the clear cover for the tie bars. Therefore, the distance from the edge of the column to the centerline of the first row of longitudinal bars is CLS plus half the diameter of the main bar.
- When using metric units for ACI design, provide values for these parameters in actual 'mm' units instead of the bar number. The following metric bar sizes are available: 6 mm, 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 32 mm, 40 mm, 50 mm, and 60 mm.
- Clear cover values are set for the concrete Not exposed to weather or in contact with ground. Plates or slabs are assumed to be reinforced with bar number 11(in imperial units) or smaller.
- Required for bar detailing in a physical member which might contain
intermediate members along with cantilevers.
For internal members both STRS and EDSP should be set to 0.
- In ACI 318-14, members are always designed with 5 sections. The parameter NSECTION used with older editions of the code has no effect.