h 12 in f'c 6000 psi

b 26 in ec 0.003

d' 2.5 in fy 75000 psi

As' 4.68 in^2 Es 29000000 psi

cover 2.5 in es 0.002586

d 23.5 in B1 0.75

As 1.58 in^2

Ast 15.6 in^2

Ag 312 in^2 1 3 1.56 4.68 2.5

TIED 0.65 2 2 1.56 3.12 9.5

3 2 1.56 3.12 16.5

TIED 0.65 4 3 1.56 4.68 23.5

SPIRAL 0.75 TOTAL 15.6 26

Bar Size Area (in2) Diameter (in)

3 0.11 0.375

4 0.20 0.500

5 0.31 0.625

Po = 2681640 lbs 6 0.44 0.750

7 0.60 0.875

= 2682 kips 1st point 8 0.79 1.000

9 1.00 1.128

10 1.27 1.270

11 1.56 1.410

14 2.25 1.693

18 4.00 2.257

.80Po = 2145 kips 2nd point

P'o = -1170000 lbs

= -1170 kips 3rd point

COLUMN INPUTS MATERIAL IMPUTS

CONCENTRIC AXIAL LOAD CAPACITY

STEEL REINFORCEMENT CACULATION

MAXIMUM (ALLOWED) AXIAL LOAD CAPACITY

PURE AXIAL TENSION CAPACITY

𝑃𝑜 = .85𝑓′𝑐 𝐴𝑔 − 𝐴𝑠𝑡 + 𝐴𝑠𝑡𝑓𝑦

=.80𝑃𝑜

𝑃′𝑜 = 𝐴𝑠𝑡𝑓𝑦

xb = 12.62037 in

(B1)*xb = 9.465278 in

Cc = 1255.096 kips

as1

es1 = 0.002406

es2 = 0.000742

es3 = -0.00092

es4 = 0.002586

fs1 = 69.76596 ksi

fs2= 21.51064 ksi

fs3 = -26.7447 ksi

fs4 = 75 ksi

F1 = 107.7086 kips

F2 = kips

F3 = kips

F4 = kips

e's = 0.002406 DOES NOT YIELD

check for yield in compression steel

BALANCE CONDITION

𝑥𝑏 =87,000

𝑓𝑦 + 87,000𝑑

𝑒′𝑠 =𝑥𝑏 − 𝑑′

𝑥𝑏. 003

fs = 69765.96 psi

Cs = 302.6367 kips

T = 118.5 kips

Pb = 1439.233 kips

force arm moment

Cc 1255.096 8.2673611 10376 kip-in

Cs 302.6367 10.5 3177.7 kip-in

T 118.5 10.5 1244.3 kip-in

Mb -1233 kip-ft

eb = -0.85684 ft

-10.2821 in

4th point

Pb = 1439.2

Mb = -1233

compute Mb

es1<.002 0.65

z1 .002<es1<.005formula

z2 .005<es1 0.9

z3 es1 phi

z4 0.00453 0.86

Z = -1

es4 = -0.002586

c = 12.62 in

a = 9.47 in

= 9.47 in

es1 = 0.002406

es2 = 0.000742

es3 = -0.000922

fs1 = 69.77 ksi

69.77 ksi

68.17 ksi

fs2 = 21.51 ksi

21.51 ksi

15.45 ksi

fs3 = -26.74 ksi

-26.74 ksi

-37.28 ksi

fs4 = -75 ksi

-75 ksi

-75 ksi

Cc = 1255.10 kips

F1 = 295.17 kips

F2 = 48.20 kips

F3 = -116.31 kips

F4 = -351.00 kips

CHOSEN POINTS

Forces Arm

Cc 1255.10 kips 18.767 in

F1 295.17 kips 21 in

F2 48.20 kips 14 in

F3 -116.31 kips 7 in

F4 -351.00 kips 0 in

Pn = 1131.15 kips 10.5

Mn = 1478.08 kip-ft

-1500

-1000

-500

0

500

1000

1500

2000

0 200 400 600 800 1000 1200 1400

(ph

i)P

n (

kip

s)

(phi)Mn (Kip-ft)

COLUMN INTERACTION DIAGRAM

z es1 phi Pn Mn (phi) Pn (phi)Mn

1 0.002586 0.7 4538 0 3177 0

0.9 0.002328 0.68 4498 32 3058 22

0.8 0.002069 0.66 4446 68 2934 45

0.7 0.00181 0.65 4389 101 2853 66

0.6 0.001552 0.65 4328 134 2813 87

0.5 0.001293 0.65 4267 167 2773 109

0.4 0.001034 0.65 4206 200 2734 130

0.3 0.000776 0.65 3849 525 2502 341

0.2 0.00517 0.65 3484 798 2264 519

0.1 0.000259 0.65 3156 992 2052 645

0 0 0.65 2875 1125 1869 731

-0.1 -0.00026 0.65 2644 1214 1719 789

-0.2 -0.00052 0.65 2425 1282 1576 833

-0.3 -0.00078 0.65 2228 1332 1448 866

MAX ALLOWED 0.65 2146 0 1395 0

-0.4 -0.00103 0.65 2045 1368 1330 889

-0.5 -0.00129 0.65 1876 1395 1220 907

-0.6 -0.00155 0.65 1719 1416 1117 921

-0.7 -0.00181 0.65 1571 1434 1021 932

-0.8 -0.00207 0.66 1432 1450 945 957

-0.9 -0.00233 0.68 1300 1463 884 995

BALANCE CONDITION -0.00259 0.7 1190 1481 833 1036

-1.1 -0.00285 0.72 1105 1462 796 1053

-1.2 -0.0031 0.74 1025 1443 758 1068

-1.3 -0.00336 0.76 948 1424 721 1083

-1.4 -0.00362 0.79 876 1406 692 1111

-1.5 -0.00388 0.81 806 1387 653 1124

-1.75 -0.00453 0.86 645 1343 554 1155

-2 -0.00517 0.9 511 1298 460 1168

-2.5 -0.00647 0.9 328 1199 295 1079

-3 -0.00776 0.9 173 1112 155 1001

-4 -0.01035 0.9 -86 961 -77 865

-5 -0.01293 0.9 -226 857 -203 771

-6 -0.01552 0.9 -324 774 -292 696

-7 -0.0181 0.9 -408 701 -367 631

-8 -0.0269 0.9 -458 657 -412 591

-9 -0.02328 0.9 -524 598 -472 538

-10 -0.02586 0.9 -586 543 -527 489

PURE AXIAL 0.9 -1170 0 -1053 0

POINTS TO PLOT