Daniel PROJECT : PAGE :

Tian LiCLIENT : DESIGN BY :

JOB NO. : DATE : REVIEW BY :

Circular Footing Design Based on ACI 318-05

INPUT DATA & DESIGN SUMMARY

COLUMN DIAMETER 12 in

COLUMN DEAD LOAD 40 kips

COLUMN LIVE LOAD 38 kips

LATERAL LOAD (0=Wind, 1=Seismic) 0 Wind,ASD

WIND AXIAL LOAD 5 k, ASD

WIND MOMENT LOAD 39.5 ft-k, ASD

WIND SHEAR LOAD 0.15 k, ASD

SOIL WEIGHT 0.11 kcf

FOOTING EMBEDMENT DEPTH 2 ft

FOOTING THICKNESS T = 18 in

ALLOW SOIL PRESSURE 2.5 ksf

FOOTING DIAMETER D = 7.5 ft

CONCRETE STRENGTH 3 ksi

REBAR YIELD STRESS 60 ksi

FOOTING TOP REBAR # 4 @ 48 in o.c., each way

FOOTING BOTTOM REBAR # 6 @ 18 in o.c., each way

THE FOOTING DESIGN IS ADEQUATE.

ANALYSIS

9.3 > F = 1.6 / 0.9 [Satisfactory]

Where 21 k-ft 196 k-ft

9.94 k, footing weight

2.43 k, soil weight

CASE 1: DL + LL P = 78.0 kips 1.2 DL + 1.6 LL = 108.8 kips

CASE 2: DL + LL + 1.3 W P = 84.5 kips 1.2 DL + LL + 1.6 W = 94.0 kips

M = 51 ft-kips = 63 ft-kips

V = 0.2 kips = 0.2 kips

e = 0.6 ft, fr cl ftg = 0.7 ft, fr cl ftg

CASE 3: DL + LL + 0.65 W P = 81.3 kips 0.9 DL+ 1.6 W = 44.0 kips

M = 26 ft-kips = 63 ft-kips

V = 0.1 kips = 0.2 kips

e = 0.3 ft, fr cl ftg = 1.4 ft, fr cl ftg

Service Loads CASE 1 CASE 2 CASE 3P 78.0 84.5 81.3 ke 0.0 0.6 0.3 ft (from center of footing)

7.5 7.5 6.8 k, (footing increasing)85.5 92.0 88.0 k, (net loads)

e 0.0 0.6 0.3 ft

1.94 0.83 1.37 ksfx @ 0.00 ft, from edge @ 0.00 ft, from edge

1.94 3.33 2.62 ksf

2.50 3.33 3.33 ksf

[Satisfactory]

CHECK FLEXURE & SHEAR OF FOOTING

(ACI 318-05 SEC.15.4.2, 10.2, 10.3.5, 10.5.4, 7.12.2, 12.2, 12.5, 15.5.2, 11.1.3.1, & 11.3)

dcol =

PDL =

PLL =

PLAT =

MLAT =

VLAT =

ws =

Df =

Qa =

fc' =

fy =

CHECK OVERTURNING FACTOR (IBC 06 1605.2.1, 1801.2.1, & ASCE 7-05 12.13.4)

MR / MO =

MO = MLAT + VLAT Df - PLAT(0.5 D) = MR = (PDL+ Pftg + Psoil) (0.5 D) =

Pftg = (0.15 kcf) p T D2/ 4 =

Psoil = ws (Df - T) p D2/ 4 =

COMBINED LOADS AT TOP FOOTING (CBC/UBC 1612.3.2, IBC 1605.3.2 & ACI 318-05 9.2.1)

Pu

Pu

Mu

Vu

eu

Pu

Mu

Vu

eu

CHECK SOIL BEARING CAPACITY (ACI 318-05 SEC.15.2.2)

Pftg - Psoil

S P

qmin

qmax

qallowable

'

'20.85 1 1

0.383Muf c b fd c

f y

40.0018 ,

3MIN

TMIN

d

'10.85

MAX

f c uf u ty

'

'20.85 1 1

0.383Muf c b fd c

f y

(cont'd)FACTORED SOIL PRESSURE Factored Loads CASE 1 CASE 2 CASE 3

108.8 94.0 44.0 k

0.0 0.7 1.4 ft

14.8 14.8 11.1 k, (factored footing & backfill)

123.6 108.8 55.1 k

0.0 0.6 1.2 ft

2.80 0.93 0.00 ksfx @ 0.00 ft, from edge @ 0.75 ft, from edge

2.80 4.00 2.81 ksf

Section 0 1/10 D 2/10 D 3/10 D 4/10 D Center 6/10 D 7/10 D 8/10 D 9/10 D D

0 0.75 1.50 2.25 3.00 3.75 4.50 5.25 6.00 6.75 7.50Tangent (ft) 0.00 4.50 6.00 6.87 7.35 7.50 7.35 6.87 6.00 4.50 0.00

0.00 2.30 3.99 4.86 5.36 11.17 5.36 4.86 3.99 2.30 0.00

0 0 0 0 0 0 81.6 163.2 244.8 326.4 408

0 0 0 0 0 54.4 108.8 108.8 108.8 108.8 108.8

0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34

0.00 0.00 0.58 2.16 4.97 9.13 16.11 24.43 33.98 44.53 55.67

0.00 0.39 1.44 2.93 4.65 7.42 10.20 11.91 13.40 14.46 14.84

-2.80 -2.80 -2.80 -2.80 -2.80 -2.80 -2.80 -2.80 -2.80 -2.80 -2.80

0 0 -4.8262 -18.029 -41.427 -76.066 -134.16 -203.5 -283 -370.93 -463.67

0 -3.2175 -12.02 -24.401 -38.691 -61.822 -84.953 -99.243 -111.62 -120.43 -123.64

0 -2.1234 -4.2468 -15.865 -36.454 -66.934 -36.454 -15.865 -4.2468 -2.1234 0

0 -2.8312 -10.577 -21.471 -34.046 0 34.046 21.4714 10.5766 2.83119 0

Section 0 1/10 D 2/10 D 3/10 D 4/10 D Center 6/10 D 7/10 D 8/10 D 9/10 D D

0 0.75 1.50 2.25 3.00 3.75 4.50 5.25 6.00 6.75 7.50Tangent (ft) 0.00 4.50 6.00 6.87 7.35 7.50 7.35 6.87 6.00 4.50 0.00

0.00 2.30 3.99 4.86 5.36 11.17 5.36 4.86 3.99 2.30 0.00

0 0 0 0 0 -31.84 6.82 77.32 147.82 218.32 288.82

0 0 0 0 0 47 94.0 94.0 94.0 94.0 94.0

0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34 0.34

0.00 0.00 0.58 2.16 4.97 9.13 16.11 24.43 33.98 44.53 55.67

0.00 0.39 1.44 2.93 4.65 7.42 10.20 11.91 13.40 14.46 14.84

0.93 1.24 1.54 1.85 2.16 2.46 2.77 3.08 3.39 3.69 4.00

0 0 -2.0199 -8.4177 -21.204 -42.205 -82.787 -133.92 -195.69 -267.07 -344.49

0 -1.42 -5.9175 -13.486 -23.752 -43.292 -64.476 -79.37 -93.6 -104.6 -108.84

0 -0.7203 -1.4405 -6.2532 -16.231 -64.913 -59.861 -32.173 -13.894 -6.9468 0

0 -1.0337 -4.4745 -10.557 -19.107 11.1302 39.7225 26.5443 13.8012 3.85843 0

Section 0 1/10 D 2/10 D 3/10 D 4/10 D Center 6/10 D 7/10 D 8/10 D 9/10 D D

0 0.75 1.50 2.25 3.00 3.75 4.50 5.25 6.00 6.75 7.50Tangent (ft) 0.00 4.50 6.00 6.87 7.35 7.50 7.35 6.87 6.00 4.50 0.00

0.00 2.30 3.99 4.86 5.36 11.17 5.36 4.86 3.99 2.30 0.00

0 0 0 0 0 -31.84 -30.68 2.32 35.32 68.32 101.32

0 0 0 0 0 22 44.0 44.0 44.0 44.0 44.0

0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25

0.00 0.00 0.43 1.62 3.73 6.85 12.08 18.32 25.48 33.40 41.75

0.00 0.29 1.08 2.20 3.48 5.57 7.65 8.94 10.05 10.84 11.13

0.00 0.12 0.55 0.98 1.41 1.84 2.28 2.71 3.14 3.57 2.81

0 0 -0.1226 -1.2188 -4.4261 -10.982 -26.656 -47.721 -74.601 -107 -143.07

0 -0.0937 -0.932 -3.2909 -7.4659 -17 -28.094 -36.663 -45.346 -52.357 -55.133

0 0.15599 0.31198 0.40454 -0.696 -35.973 -45.256 -27.078 -13.797 -6.8985 0

0 0.19597 0.15021 -1.0938 -3.9821 10.5673 23.5551 16.2727 8.7048 2.48591 0

Pu

eu

g[0.15T + ws(Df - T)] A

S Pu

eu

qu, min

qu, max

FOOTING MOMENT & SHEAR FOR CASE 1

Xu (ft, dist. from left of footing)

TA ( ft2 )

Mu,col (ft-k)

Vu,col (k)

qu,ftg & fill (ksf)

Mu,ftg & fill (ft-k)

Vu,ftg & fill (k)

qu,soil (ksf)

Mu,soil (ft-k)

Vu,soil (k)

S Mu (ft-k)

S Vu (kips)

FOOTING MOMENT & SHEAR FOR CASE 2

Xu (ft, dist. from left of footing)

TA ( ft2 )

Mu,col (ft-k)

Vu,col (k)

qu,ftg & fill (ksf)

Mu,ftg & fill (ft-k)

Vu,ftg & fill (k)

qu,soil (ksf)

Mu,soil (ft-k)

Vu,soil (k)

S Mu (ft-k)

S Vu (kips)

FOOTING MOMENT & SHEAR FOR CASE 3

Xu (ft, dist. from left of footing)

TA ( ft2 )

Mu,col (ft-k)

Vu,col (k)

qu,ftg & fill (ksf)

Mu,ftg & fill (ft-k)

Vu,ftg & fill (k)

qu,soil (ksf)

Mu,soil (ft-k)

Vu,soil (k)

S Mu (ft-k)

S Vu (kips)

(cont'd)FOOTING MOMENT & SHEAR SUMMARY

Section 0 1/10 D 2/10 D 3/10 D 4/10 D Center 6/10 D 7/10 D 8/10 D 9/10 D D

0 0.75 1.50 2.25 3.00 3.75 4.50 5.25 6.00 6.75 7.50Tangent (ft) 0.00 4.50 6.00 6.87 7.35 7.50 7.35 6.87 6.00 4.50 0.00

Un

ifo

rm L

oad

s

Case 0 -0.4719 -0.7078 -2.308 -4.9607 -8.9245 -4.9607 -2.308 -0.7078 -0.4719 0

1 0 -0.6292 -1.7628 -3.1236 -4.6331 0 4.63308 3.12362 1.76276 0.62915 0

Case 0 -0.1601 -0.2401 -0.9097 -2.2087 -8.6551 -8.146 -4.6804 -2.3156 -1.5437 0

2 0 -0.2297 -0.7458 -1.5358 -2.6001 1.48402 5.40555 3.86163 2.3002 0.85743 0

Case 0 0.03466 0.052 0.05885 -0.0947 -4.7964 -6.1586 -3.9393 -2.2995 -1.533 0

3 0 0.04355 0.02503 -0.1591 -0.5419 1.40897 3.20544 2.36733 1.4508 0.55242 0

CHECK FLEXURE

Location d (in)

Top Slab 0.1 ft-k / ft 15.75 0.0000 0.0000 0.0155 no limit 0.0003

Bottom Slab -8.9 ft-k / ft 14.63 0.0010 0.0008 0.0155 18 0.0017 [Satisfactory]

CHECK FLEXURE SHEAR

5.4 k / ft 14 k [Satisfactory]

Case y R J

1 108.8 0.0 21.4 21.4 7.1 0.4 1.0 2.0 44.2 9.0 7.8 5.4 77.9 164.3

2 94.0 63.7 21.4 21.4 7.1 0.4 1.0 2.0 44.2 9.0 6.7 5.4 67.5 164.3

3 44.0 63.7 21.4 21.4 7.1 0.4 1.0 2.0 44.2 9.0 3.2 5.4 31.7 164.3

[Satisfactory]

where f = 0.75 (ACI 318-05, Section 9.3.2.3 )

Xu (ft, dist. from left of footing)

Mu, (ft-k / ft)

Vu, (k / ft)

Mu, (ft-k / ft)

Vu, (k / ft)

Mu, (ft-k / ft)

Vu, (k / ft)

Mu,max min reqD max smax provD

Vu,max fVc = 2 f b d (fc')0.5 check Vu < f Vc

CHECK PUNCHING SHEAR (ACI 318-05 SEC.15.5.2, 11.12.1.2, 11.12.6, & 13.5.3.2)

Pu Mu b1 b2 b0 gv c Af Ap vu (psi) f vc

0.5 1( )

231 21 36 1 1

1 2

R bMP uu vpsivu JAP

db d bJb b

b bPuRA f

g

2 1 21

12 113 22

4

db bAP

vb

b

DA f

g

p

'( ) 2

42, , 40

0

0,0 1 2 4

psi y fvc c

dy MIN

bc

bdb d b bcol

ff

p