V. ACI 318-99 Square Column
Determine the reinforced steel quantity for the square column as per ACI 318-99.
Reference
Chu-Kia Wang and Charles G.Slamon, Reinforced Concrete Design, 5th Edition, Examples problem 13.21.1, p509 .
Problem
Pu = 144 kipsMuz = 120 ft·kipsMuy = 54 ft·kipsf'c = 3,000 psify = 60,000 psi
Comparison
| Result Type | Reference | STAAD.Pro | Difference |
|---|---|---|---|
| Provided steel area per ACI 318-99(in2) | 8.0 (8- #9) | 9.0 (4- #14) | none |
Note: In the reference book, the axial capacity provided is 141 kips, which is less than the requirement of 144 kips. In the STAAD implementation of the code, any reinforcement arrangement which yields less capacity than the required value is considered un-acceptable. This is why STAAD reports a higher required steel than the reference book.
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Verification Models\10 Concrete Design\US\ACI 318-99 Square Column.STD is typically installed with the program.
STAAD SPACE SQUARE COLUMN DESIGN ACI 318-99
START JOB INFORMATION
ENGINEER DATE 23-Sep-18
END JOB INFORMATION
*
* REFERENCE : REINFORCED CONCRETE DESIGN 5TH EDITION BY CHU-KIA WANG
* AND CHARLES G.SALMON EX.13.21.1 PAGE 509.
*
* OBJECTIVE : TO DETERMINE THE REINFORCED STEEL QUANTITY FOR A
* SQUARE COLUMN PER THE ACI 318-99 CODE
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 0 12 0;
MEMBER INCIDENCES
1 1 2;
UNIT INCHES KIP
MEMBER PROPERTY AMERICAN
1 PRIS YD 16 ZD 16
DEFINE MATERIAL START
ISOTROPIC MATERIAL1
E 3150
POISSON 0.17
END DEFINE MATERIAL
CONSTANTS
MATERIAL MATERIAL1 ALL
SUPPORTS
1 FIXED
UNIT FEET KIP
LOAD 1
JOINT LOAD
2 FY -144
2 MZ 120
2 MX 54
PERFORM ANALYSIS
START CONCRETE DESIGN
CODE ACI 1999
UNIT INCHES KIP
FC 3 ALL
FYMAIN 40 ALL
FYSEC 40 ALL
MINMAIN 9 ALL
TRACK 2 ALL
DESIGN COLUMN ALL
END CONCRETE DESIGN
FINISH
STAAD Output
SQUARE COLUMN DESIGN ACI 318-99 -- PAGE NO. 3
====================================================================
COLUMN NO. 1 DESIGN PER ACI 318-99 - AXIAL + BENDING
FY - 40000 FC - 3000 PSI, SQRE SIZE - 16.00 X 16.00 INCHES, TIED
AREA OF STEEL REQUIRED = 8.348 SQ. IN.
BAR CONFIGURATION REINF PCT. LOAD LOCATION PHI
----------------------------------------------------------
4 - NUMBER 14 3.516 1 END 0.700
(PROVIDE EQUAL NUMBER OF BARS ON EACH FACE)
TIE BAR NUMBER 4 SPACING 16.00 IN
COLUMN INTERACTION: MOMENT ABOUT Z -AXIS (KIP-FT)
--------------------------------------------------------
P0 Pn max P-bal. M-bal. e-bal.(inch)
989.85 791.88 312.89 272.99 10.47
M0 P-tens. Des.Pn Des.Mn e/h
178.89 -360.00 205.71 171.43 0.06944
--------------------------------------------------------
COLUMN INTERACTION: MOMENT ABOUT Y -AXIS (KIP-FT)
--------------------------------------------------------
P0 Pn max P-bal. M-bal. e-bal.(inch)
989.85 791.88 312.89 272.99 10.47
M0 P-tens. Des.Pn Des.Mn e/h
178.89 -360.00 205.71 77.14 0.03125
--------------------------------------------------------
Pn Mn Pn Mn (@ Z )
| 730.97 130.65 365.48 257.21
P0 |* 670.05 156.16 304.57 272.89
| * 609.14 178.25 243.66 267.81
Pn,max|__* 548.22 199.53 182.74 255.16
| * 487.31 219.54 121.83 234.02
Pn | * 426.40 238.66 60.91 206.96
NOMINAL| * Pn Mn Pn Mn (@ Y )
AXIAL| * 730.97 130.65 365.48 257.21
COMPRESSION| * 670.05 156.16 304.57 272.89
Pb|-------*Mb 609.14 178.25 243.66 267.81
| * 548.22 199.53 182.74 255.16
___________|____*_______ 487.31 219.54 121.83 234.02
| * M0 Mn, 426.40 238.66 60.91 206.96
| * BENDING
P-tens|* MOMENT
|
********************END OF COLUMN DESIGN RESULTS********************