Combined Footing _type2

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22

0.34 4.17 4.42 4.69 4.98 5.28 5.62 5.97

0.32 3.7 3.93 4.17 4.43 4.7 4.99 5.31 5.66 6.04 6.46

0.3 3.33 3.54 3.75 3.98 4.23 4.49 4.78 5.09 5.43 5.81 6.23 6.69

0.28 3.03 3.22 3.41 3.62 3.84 4.08 4.35 4.63 4.94 5.28 5.66 6.08

0.26 2.78 2.95 3.13 3.32 3.52 3.74 3.98 4.24 4.53 4.84 5.19 5.57

0.24 2.56 2.72 2.88 3.06 3.25 3.46 3.68 3.92 4.18 4.47 4.79 5.15

0.22 2.38 2.53 2.68 2.84 3.02 3.2 3.41 3.64 3.88 4.15 4.44 4.77

0.2 2.22 2.36 2.5 2.66 2.82 2.99 3.18 3.39 3.62 3.86 4.14 4.44

0.18 2.08 2.21 2.35 2.49 2.64 2.8 2.98 3.17 3.38 3.61 3.86 4.15

0.16 1.96 2.08 2.21 2.34 2.48 2.63 2.8 2.97 3.17 3.38 3.62 3.88

0.14 1.84 1.96 2.08 2.21 2.34 2.48 2.63 2.79 2.97 3.17 3.39 3.64

0.12 1.72 1.84 1.96 2.08 2.21 2.34 2.48 2.63 2.8 2.98 3.18 3.41

0.1 1.6 1.72 1.84 1.96 2.08 2.2 2.34 2.48 2.63 2.8 2.99 3.2

0.08 1.48 1.6 1.72 1.84 1.96 2.08 2.21 2.34 2.48 2.64 2.82 3.02

0.06 1.36 1.48 1.6 1.72 1.84 1.96 2.08 2.21 2.34 2.49 2.66 2.84

0.04 1.24 1.36 1.48 1.6 1.72 1.84 1.96 2.08 2.21 2.35 2.5 2.68

0.02 1.12 1.24 1.36 1.48 1.6 1.72 1.84 1.96 2.08 2.21 2.36 2.53

0 1 1.12 1.24 1.36 1.48 1.6 1.72 1.84 1.96 2.08 2.22 2.38

ex / Lx ez / Lzk1 = 1.000

0.00 0.00

ex / Lx ez / Lzk2 = 1.000

0.00 0.00

ex / Lx ez / Lzk3 = 1.000

0.00 0.00

k1 1.000k2 1.000k3 1.000

7.48337

ex/Lx

ey/Ly

0.24 0.26 0.28 0.3 0.32 0.34

6.56

6.01 6.51

5.55 6.01 6.56

5.15 5.57 6.08 6.69

4.79 5.19 5.66 6.23

4.47 4.84 5.28 5.81 6.46

4.18 4.53 4.94 5.43 6.04

3.92 4.24 4.63 5.09 5.66

3.68 3.98 4.35 4.78 5.31 5.97

3.46 3.74 4.08 4.49 4.99 5.62

3.25 3.52 3.84 4.23 4.7 5.28

3.06 3.32 3.62 3.98 4.43 4.98

2.88 3.13 3.41 3.75 4.17 4.69

2.72 2.95 3.22 3.54 3.93 4.42

2.56 2.78 3.03 3.33 3.7 4.17

G289+M293*K309-K309*(M299+(M297-M299)*(1-K309/B59))-0.5*K309*(M297-M299)/B59G289+M293*K309-K309*(M299+(M297-M299)*(1-K309/B59))-0.5*K309^2*(M297-M299)/B59

F316*(K309^2)/2+0.5*(M297-F316)*(K309^2)*2/3-G289*(K309-(B59-J59)/2)-G291-M293*K309^2/2F316*(K309^2)/2+0.5*(M297-F316)*(K309^2)*2/3-G289*(K309-(B59-J59)/2)-G291-M293*K309^2/2

Client : NTPC Limited. Calc No. 9558-360-POC-U-848Project : Barh (3x660 MW) STPP Rev. 0 .Project No. : T413000 Page

DESIGN OF COMBINED FOUNDATION MARKED F5( With ground water table at FGL. )

LOAD TABLE ( Units kN & m )

Pedestal - I Pedestal - II

V1 Hx1 Hz1 Mx1 Mz1 V2 Hx2 Hz2 Mx2

3101 1 F 27 25 26 205 40 76 2 11.5 53

UNIT WEIGHTS ( Units Mton / cu.m. )

= 25= 20.0

SOIL PROPERTIES ( Units KN / sq.m.)

P_net = 175 Friction between conc.

= 0.4

MATERIAL GRADES ( Units MPa )

Concrete ( fck ) = 25Reinforcement ( fy ) = 460

CLEAR COVER ( Unit mm ):

In pedestal ( Cp ) = 50In footing ( Cf ) = 75

BAR DIAMETER ( Unit mm ):

In footing (X dir. top) = 12In footing (X dir. bott) = 16In footing (Z dir. top) = 12In footing (Z dir. bott) = 16

TRIAL SIZE OF COLUMN & FOUNDATION ( Units m )

Lx Lz T Df lx lz Dw Dl L3.0 1.8 0.3 1.2 0.5 0.5 10 1.2 2

Node no.

Load comb.

Concrete ( gc )Soil ( gs )

& soil ( m )


LOAD & BEARING PRESSURE CALCULATION ( Units kN & m )

Total load & moments on foundation transferred from superstructure :

Vertcal load ( V ) = V1 + V2

Horizontal forces : Hx = Hx1 + Hx2 ; Hz = Hz1 + Hz2

Moment about X - axis ( Mx ) = Mx1 + Mx2

Eccentricity of direct load along X - axis ( e ) = L. [ 0.5 - { V1 / ( V1 + V2 )}]

Moment about Z - axis ( Mz ) = Mz1 + Mz2 + V.e

Calculated load & moments are tabulated below :

V Hx Hz Mx e Mz

3101 1 F 103 27 37.5 209.5 0.476 93.5

Weight of pedestal ( Wp ) = 15.00 kN

Weight of footing ( Wf ) = 41 kN

Weight of soil overburden ( Ws )= 88 kN

Total vertical load on foundation :

Total moment @ X direction :

Total moment @ Z direction :

Maximum gross bearing pressure :

Minimum gross bearing pressure :

Modified bearing pressure in case of tension being developed below footing :

Node no.

Load comb.

2.lx.lz.Dl.gc =

Lx.Lz.T.gc =

(Lx.Lz-2.lx.lz).(Df-T).gs =

SV = V+Wp+Wf+Ws-Fb

SMx = Mx

SMz = Mz

P_max = SV / (Lx.Lz) + 6.SMx / (Lx.Lz2) + 6.SMz / (Lz.Lx2)

P_min = SV / (Lx.Lz) - 6.SMx / (Lx.Lz2) - 6.SMz / (Lz.Lx2)


where, ' K ' is the bearing pressure co-efficient as given in section 6.9 of"FOUNDATION DESIGN" by W.C.Teng.

K = function of ( ex/Lz, ez/Lx ), &

Allowable gross bearing pressure :

= 199

Bearing pressure calculation is done in a tabular form as shown below :

P_max P_min ex/Lz ez/Lx P_mod

3101 1 F 246.70 265.75 134.00 259.36 -167.99 0.60 0.18 3.00 137.06

UNSAFE, SINCE LOSS OF CONTACT IS MORE THAN 30%.

CHECK FOR STABILITY

Overturning :

Sliding :

Allowable minimum factor of safety are as follows :

Against overturning = 1.5Against sliding = 1.5

Check against overturning :

Mrx Mrz

P_mod = K. SV / ( Lx. Lz )

ex = SMx / SV ez = SMz / SV

P_all = (P_net) + gs.x Df

Node no.

Load comb.

SV SMx SMz" K " after

"Teng"

Maximum overturning moment about Lx side = SMx

Maximum overturning moment about Lz side = SMz

Restoring moment about Lx side ( Mrx ) = SV. Lz / 2

Restoring moment about Lz side ( Mrz ) = SV. Lx / 2

Resultant sliding force ( Hm ) = Hx2 + Hz2 in respective load case.

Restoring force ( Hr ) = m. SV in respective load case.

Node no.

Load comb.

SMx F.O.S. = Mrx/SMx SMz F.O.S. =

Mrz/SMz


3101 1 F 265.75 222.03 0.84 134.00 370.05 2.8 UNSAFE

Check against sliding and uplift :

Hm Hr

3101 1 F 46.2 98.7 2.1 O.K.

V1 + Wp = P1 V2 + Wp = P2

M1 L M2

w

y2y1

x Point of Max. B.M.Lx

In the above diagram ( All units are Mton & m ),

P1 = V1 + Wp = 8.30 P2 = V2 + Wp =

M1 = Mz1 + Hx1.(Dl+T) = 0.1 M2 = Mz2 + Hx2. (Dl+T) =

Downward U.D.L. per unit length of footing w = ( Wf + Ws - Fb ) / Lx =

Ordinate of distributed reaction for full width below foundation :

246.7 134

Bending moment will be maximum at a distance ' x ' where shear force is zero.

Shear force at a distance ' x ' is given by

Node no.

Load comb.

F.O.S. = Hr/Hm

DESIGN OF FOOTING - For Load Combination, which yields maximum pressure.

Analysis of footing slab in X - direction : Free-body diagram is shown below.

For SV = & SMz = y1 = SV / Lx + 6. SMz / Lx2 =

y2 = SV / Lx - 6. SMz / Lx2 =


= P1 + w.x - { y2 + (y1 - y2).(Lx - x)/Lx }.x - 0.5 x.{ y1 - y2 - (y1 - y2).(Lx - x)/Lx }

Shear force will be 183.30 at a distance x = 3.5 m

Ordinate of bearing pressure at the point of maximum bending moment

y = y2 + (y1 - y2). (Lx - x)/Lx

y = -36.878 Mton / m

Bending moment in the footing slab about point located at " x "

BM1 =

BM1 = 337.509259 Mton-m Tension at bottom of footing

Bending moment per unit width of footing = BM1 / Lz = 187.51 Mton-m/m

Cantilever length ( lcx ) in m = ( Lx - L - lx ) / 2 = 0.25

4.02 Tension at bottomin the overhang part


= 201

Shear force in Mton at a distance "d" from the face of pedestal towards the centreis obtained from equation - 1, putting x = 0.951

SF1 = -87.13

Shear force per unit width of footing = SF1 / Lz = -48.41 Mton/m

Shear force in Mton at a distance "d" from the face of pedestal towards cantilever sideis conservatively given by : SF2 = ( y1 - w ) x ( lcx - d )

SF2 = 6.30

Shear force per unit width of footing = SF2 / Lz = 3.50 Mton/m

subjected to an U.D.L., which is equal to the net bearing pressure.

Maximum gross bearing pressure Pg = 259.36

= P1 + w.x - x.{ y2 + (y1 - y2).(1 - x/Lx) } - 0.5 x2.(y1-y2)/Lx

y. x2/2 + 0.5. ( y1 - y ). x2. 2/3 - P1. { x - ( Lx - L )/2 } - M1 - w. x2/2

Bending moment ( BM2 ) in Mton-m = ( y1 - w ). lcx2 / 2 =

Effective depth ( d ) of footing slab in mm = T.103 - Cf - 1.5 x Bar dia.

Analysis of footing slab along Z - axis : Footing slab is analysed as cantilever of unit width

Mton / m2


= 226.558

Cantilever length ( lcz ) = ( Lz - lz ) / 2 = 0.650 m

47.86 Mton-m / m ( Tension at bottom )

Shear force at a distance "d" from the face of pedestal = Pn. ( lcz - d/1000 )

SF3 = 101.72 Mton / m

Analysis along Z - axis for tension at top:

Minimum gross bearing pressure ( Mton/sq.m. ) P_min = ###

Minimum net bearing pressure P'n ( Mton/sq.m. )

= -200.79

Since P'_net is ( - )ve, top reinforcement is required to be designed.

-42.42

Shear force in Mton / m. at the face of pedestal

= P'n. lcz

= -130.51

Computation of %age of steel as per SP:16, pertaining to the aforesaid B.M. & S.F.is tabulated below ( Minimum %age is considered as pt = 0.2 ) :

Tension at

X Top 0 0.00 0.00 -48.41 -3.51 5.55 5.55X Bottom 2.23 0.83 0.22 3.50 0.26 0.12 0.22Z Top 42.42 14.85 Err:502 130.51 9.46 -26.09 ###Z Bottom 47.86 17.77 Err:502 101.72 7.59 -22.03 ###

Reinforcement Summary :

Maximum net bearing pressure Pn = Pg - gs.Dw - ( gs -1.0 ).( Df - Dw )

Mton / m2

Bending moment ( BM3 ) = Pn. lcz2 / 2 =

= P_min - gs.Dw - ( gs -1.0 ).( Df - Dw )

Bending moment in Mton-m / m = P'n. lcz2 / 2 =

Direc- tion

B.M. (Mton-m/m)

Mu/bd2 (MPa)

pt (%) as per

SP:16

S.F. (Mton/m

)

Vu/bd (MPa)

pt (%) as per SP:16

pt (%) reqd.


Face

X Top 11154.7042 12 150 753.6X Bottom 433.995198 16 150 1339.73Z Top Err:502 12 175 645.943Z Bottom Err:502 16 175 1148.34

Check for punching shear :

Three faces of the column shall be effective in resisting punching shear.

Periphery of punching shear ( Bo ) in m = 2. [( lx + d ) + ( lz + d )]

= 2.80

Punching load ( Pp ) in Mton = Vmax + Wp Vmax = Maximum direct load on column

= 91.00 = 76 Mton

= 2.42

Allowable punching shear stress in MPa = 0.25 fck

= 1.25 UNSAFE

Direc- tion

Ast (mm2 /m)

= pt.b.d 100

Bar dia. (mm)

Spacing (mm)

Ast provided (mm2 /m)

Punching shear is critical at a distance of " d / 2 " from the face of column.

Punching shear stress ( tc ) in MPa = 1.5. Pp. 104 / ( Bo. d )

Calc No. 9558-360-POC-U-848

Pedestal - II

Mz2

4.5

Calc No. 9558-360-POC-U-848

Calc No. 9558-360-POC-U-848

Remarks

UNSAFE 45.68519 164.0432 49.62963 259.358

Calc No. 9558-360-POC-U-848

Point of Max. B.M.

8.40

0.1

42.90

171.57

-7.10

Calc No. 9558-360-POC-U-848

Mton-m/m

Tension at bottom

Mton-m/m

1

Calc No. 9558-360-POC-U-848

( Tension at bottom )

Calc No. 9558-360-POC-U-848

Vmax = Maximum direct load on column

Sheet 13DESIGN OF COMBINED FOUNDATION MARKED F1

LOAD TABLE ( Units kN & m )


V1 Hx1 Hz1 Mx1 Mz1 V2 Hx2 Hz2 Mx2 Mz2

7&33 104 120 3 1 0 0 -83 2 21 0 0

UNIT WEIGHTS ( Units kN / cu.m. )

= 25= 18.0

SOIL PROPERTIES ( Units KN / sq.m.)

P_net = 150 Friction between conc.

= 0.4


Concrete ( fcu ) = 40Reinforcement ( fy ) = 460






Lx Lz T Df lx lz Dw Dl L2.70 1.80 0.35 1.20 0.60 0.40 5.00 1.05 1.00

LOAD & BEARING PRESSURE CALCULATION ( Units kN & m )


Vertical load ( V ) = V1 + V2






V Hx Hz Mx e Mz

7&33 104 37 5 22 0 2.743 101.5

Node no.

Load comb.


& soil ( m )

Node no.

Load comb.

Sheet 14Weight of pedestal ( Wp ) = 12.60 kN

Weight of footing ( Wf ) = 43 kN

Weight of soil overburden ( Ws )= 67 kN


Total moment @ X direction :

Total moment @ Z direction :







= 171.6


P_max P_min ex/Lz ez/Lx P_mod Remarks

7&33 104 159.14 30.80 108.50 103.48 -37.99 0.11 0.25 3.72 121.65 O.K.

2.lx.lz.Dl.gc =

Lx.Lz.T.gc =


SV = V+Wp+Wf+Ws-Fb

SMx = Mx

SMz = Mz





P_all = (P_net) + gs.x Df

Node no.

Load comb.


"Teng"

Sheet 15CHECK FOR STABILITY

Overturning :

Sliding :


Against overturning = 1.5Against sliding = 1.5


Mrx Mrz

7&33 104 30.80 143.23 4.65 108.50 214.84 2.0 O.K.

Check against sliding :

Hm Hr

7&33 104 22.6 63.7 2.8 O.K.

Maximum overturning moment about Lx side = SMx

Maximum overturning moment about Lz side = SMz

Restoring moment about Lx side ( Mrx ) = SV. Lz / 2

Restoring moment about Lz side ( Mrz ) = SV. Lx / 2



Node no.

Load comb.


Mrz/SMz

Node no.

Load comb.

F.O.S. = Hr/Hm

Sheet 16DESIGN OF FOOTING -

V1 + Wp = P1 V2 + Wp = P2

M1 L M2

w

Design pres.p = 121.65 X 1.2

Design = 146.0 (Factored)

Conservatively uniform pressure has been considered to get maximum moment and shear forceMoment at the Critical section (Centre): -34.49 KN-m/m Width of Footing.Shear at critical section d: 10.07 KN

Tensile Reinforcement:Effective depth d = 269.00 mm

= -0.01191 < 0.156= 272.52 mm

0.95*d = = 255.55 mmHence z = = 255.55 mm

= -308.81

Minimum Reinforcement 0.13% = = 455.00Reqd. Spacing of mm dia bar = 249 mmProvided Spacing = 200 mm 565

= 0.485 0.2102

0.037 Value for calc = 0.2102 O.K.

400/d = 1.487 Check for Punching Shear Value for calc = 1.487

0.415

d = average of effective depth in two directions = 263 mm

2000 mm

5156 mm

190.9668 KN (Factored)

0.141

5.060 O.K.


kN/m2

K= M/fcubd2 =z= d[0.5+Ö(0.25-k/0.9)] =

Ast = M/0.95fyz = mm2/m

mm2/m

Ast,provided mm2/m

Design Concrete shear stress uc = N/mm2 100As/bvd =

Ultimate shear stress v1 = N/mm2

U0 = 2(LX+LZ) =

U1 =U0 +12d =

Maximum ultimate Vertical load on column FY =

Ultimate shear stress for U1 = N/mm2

Maximum allowed 0.8Öfcu = N/mm2

UO

U1

1.5d

1.5d

Area, A 8.75 Zx 2.33

Depth of FDN, d 1.3 m Zz 4.08Support Reaction for FDN 2

Node L/C26 101 0.22 96.72 0.04 -37.36 0.01 0.34

102 -16.90 46.20 -18.44 -199.60 0.06 30.77103 -49.34 -20.88 -20.69 -217.95 -0.06 89.99104 7.48 107.58 -16.19 -181.24 0.18 -13.57105 -20.93 43.35 -31.46 -281.22 1.09 38.21106 -20.93 43.35 -5.43 -117.97 -0.97 38.21107 -26.75 26.29 -18.44 -199.60 0.06 48.62108 -15.11 60.41 -18.44 -199.60 0.06 27.81109 -20.93 43.35 -21.60 -227.21 0.18 38.21110 -20.93 43.35 -15.28 -171.99 -0.06 38.21111 -28.27 -15.75 -2.24 -30.71 -0.12 51.91112 28.55 112.71 2.26 6.00 0.12 -51.66113 0.14 48.48 -13.01 -93.98 1.03 0.13114 0.14 48.48 13.03 69.27 -1.03 0.12

27 101 -0.22 61.46 -0.04 -3.37 -0.09 0.69102 -5.75 125.10 -4.21 -45.64 -0.34 21.78103 -4.81 192.19 -1.96 -27.28 -0.40 17.94104 1.36 63.73 -6.46 -63.99 -0.27 -3.53105 -1.72 127.96 -15.36 -116.27 -0.42 7.20106 -1.72 127.96 6.94 25.00 -0.25 7.20107 -2.13 145.01 -4.21 -45.64 -0.34 8.98108 -1.31 110.90 -4.21 -45.64 -0.34 5.42109 -1.72 127.96 -7.28 -72.85 -0.34 7.20110 -1.72 127.96 -1.14 -18.42 -0.33 7.20111 -3.23 99.45 2.24 17.24 -0.10 11.16112 2.94 -29.01 -2.26 -19.47 0.04 -10.30113 -0.14 35.22 -11.16 -71.75 -0.12 0.43114 -0.14 35.22 11.14 69.52 0.06 0.43

m2 m3

m3

Force-X kN

Force-Y kN

Force-Z kN

Moment-X kNm

Moment-Y kNm

Moment-Z kNm



LOAD TABLE ( Units Mton & m )



52&32 1203 25.1 -0.57 -6.4 -15.57 -1.042 24.6 0.34 -6.4 -15.66 0.357&37 1230 47.6 7.4 -0.08 0.4 18.87 47.1 7 -0.1 0.4 18.2157&37 1204 20.7 -7.1 -0.2 0.01 -18.6 20.4 -7.5 -0.2 0.01 -19.257&37 1171 47.9 0.23 5.5 14.6 0.4 47.1 -0.1 5.5 14.6 0.0857&37 1203 20.4 0.012 -5.8 -14.2 -0.17 20.4 -0.45 -5.8 -14.1 -0.94

###############


= 2.5= 1.6

SOIL PROPERTIES ( Units Mton / sq.m.)

P_net = 7.5 ( P_net is net bearing capacity at 3.5m depth. )Friction between conc.

= 0.55








Lx Lz T Df lx lz Dw Dl L7 3.5 0.5 4.7 0.6 0.4 4.7 0 2.6

Node no.

Load comb.


& soil ( m )

Change the digits in shaded area only.


LOAD & BEARING PRESSURE CALCULATION ( Units Mton & m )








V Hx Hz Mx e Mz

52&32 1203 49.7 -0.23 -12.8 -31.23 0.013 -0.09257&37 1230 94.7 14.4 -0.18 0.8 0.007 37.7357&37 1204 41.1 -14.6 -0.4 0.02 0.009 -37.4157&37 1171 95 0.13 11 29.2 0.011 1.5257&37 1203 40.8 -0.438 -11.6 -28.3 0.000 -1.11

Weight of pedestal ( Wp ) = 0.00

Weight of footing ( Wf ) = 30.63

Weight of soil overburden ( Ws )= 161

Buoyant force ( Fb ) = Lx.Lz.(Df-Dw) = 0.00


Total moment in X direction :

Total moment in Z direction :


Node no.

Load comb.

2.lx.lz.Dl.gc =

Lx.Lz.T.gc =


SV = V+Wp+Wf+Ws-Fb

SMx = Mx+Hz.(Dl+T)

SMz = Mz+Hx.(Dl+T)








= 14.975



52&32 1203 241.74 31.23 0.09 12.06 7.68 _ _ _ O.K.

57&37 1230 286.74 0.80 37.73 13.08 10.33 _ _ _ O.K.

57&37 1204 233.14 0.02 37.41 10.83 8.21 _ _ _ O.K.

57&37 1171 287.04 29.20 1.52 13.81 9.62 _ _ _ O.K.

57&37 1203 232.84 28.30 1.11 11.52 7.48 _ _ _ O.K.

###

###

###

###

###

CHECK FOR STABILITY

Overturning :




P_all = 1.25 (P_net) + gs. X 3.5

Node no.

Load comb.


"Teng"

Maximum overturning moment about Lx side = SMx in respective load case.


Sliding :

Uplift :

Upward force = Fb

Downward force ( Fd ) = V + Wp + Wf + Ws


Against overturning = 1.5Against sliding = 1.5Against uplift = 1.2


Mrx Mrz

52&32 1203 31.23 423.04 13.55 0.09 846.1 9196.657&37 1230 0.80 501.79 627.24 37.73 1003.6 26.657&37 1204 0.02 407.99 20399.7 37.41 816.0 21.857&37 1171 29.20 502.32 17.20 1.52 1004.6 660.957&37 1203 28.30 407.47 14.40 1.11 814.9 734.2

Minimum F.O.S. against overturning about Lz = 13.5 O.K.

Minimum F.O.S. against overturning about Lx = 21.8 O.K.


Hm Hr Fb Fd

52&32 1203 12.8 133.0 10.4 0.0 217.1 N.A.57&37 1230 14.4 157.7 11.0 0.0 239.6 N.A.57&37 1204 14.6 128.2 8.8 0.0 212.7 N.A.

Maximum overturning moment about Lz side = SMz in respective load case.

Restoring moment about Lx side ( Mrx ) = SV. Lz / 2 in respective load case.

Restoring moment about Lz side ( Mrz ) = SV. Lx / 2 in respective load case.



Node no.

Load comb.


Mrz/SMz

Node no.

Load comb.

F.O.S. = Hr/Hm

F.O.S. = Fd/Fb


57&37 1171 11.0 157.9 14.4 0.0 239.9 N.A.57&37 1203 11.6 128.1 11.0 0.0 212.4 N.A.

Mininmum F.O.S. against sliding = 8.78 O.K.

Mininmum F.O.S. against uplift = N.A. O.K.

V1 + Wp = P1 V2 + Wp = P2

M1 L M2

w

y2y1



P1 = V1 + Wp = 47.60 P2 = V2 + Wp = 47.10

M1 = Mz1 + Hx1.(Dl+T) = 18.9 M2 = Mz2 + Hx2. (Dl+T) = 18.21

Downward U.D.L. per unit length of footing w = ( Wf + Ws - Fb ) / Lx = 27.43


287.04 1.52 41.19

40.82




y2 = SV / Lx - 6. SMz / Lx2 =







y = y2 + (y1 - y2). (Lx - x)/Lx

y = 41.0056 Mton / m


BM1 =






= 426


SF1 = 7.57



SF2 = 20.28



y. x2/2 + 0.5. ( y1 - y ). x2. 2/3 - P1. { x - ( Lx - L )/2 } - M1 - w. x2/2




1




= 6.2922




SF3 = 7.07 Mton / m


Minimum gross bearing pressure ( Mton/sq.m. ) P_min = 7.48


= -0.04


-0.04


= P'n. lcz

= -0.05

Computation of % age of steel as per SP:16, pertaining to the aforesaid B.M. & S.F.is tabulated below ( Minimum %age is considered as pt = 0.2 ) :

X Top 0 0.00 0.00 2.16 0.08 0.01 0.12X Bottom 7.09 0.59 0.17 5.79 0.20 0.07 0.20Z Top 0.04 0.00 0.00 0.05 0.00 0.00 0.12Z Bottom 7.56 0.62 0.18 7.07 0.25 0.11 0.20

Mton / m2


Mton / m2


= P_min - gs.Dw - ( gs -1.0 ).( Df - Dw )


Direc- tion

Tension at

B.M. (Mton-m/m)

Mu/bd2 (MPa)

pt (%) as per SP:16

S.F. (Mton/

m)

Vu/bd (MPa)

pt (%) as per SP:16

pt (%) reqd.



Face

X Top 511.2 12 150 753.6X Bottom 852 16 150 1339.7Z Top 511.2 12 175 645.94Z Bottom 852 16 175 1148.3




= 3.70


= 47.90 = 47.9 Mton

= 0.46


= 1.25 O.K.

Direc- tion

Ast (mm2 /m) = pt.b.d

100

Bar dia. (mm)

Spacing (mm)









60&40 1230 33.8 5.4 0 0 11.5 33.9 5.1 0 0.01 11.260&40 1204 8 -5.2 0 -0.1 -11.3 8.1 -5.4 0 -0.1 -11.658&38 1203 16.9 -0.05 -1.7 -6.8 -0.2 16.8 -0.3 -1.8 -6.9 -0.5

#####################


= 2.5= 1.6



= 0.55








Lx Lz T Df lx lz Dw Dl L6 3 0.5 4.7 0.6 0.4 4.7 0 2.6

Node no.

Load comb.


& soil ( m )











V Hx Hz Mx e Mz

60&40 1230 67.7 10.5 0 0.01 0.002 22.8360&40 1204 16.1 -10.6 0 -0.2 0.008 -22.7758&38 1203 33.7 -0.35 -3.5 -13.7 0.004 -0.57









Node no.

Load comb.

2.lx.lz.Dl.gc =

Lx.Lz.T.gc =


SV = V+Wp+Wf+Ws-Fb

SMx = Mx+Hz.(Dl+T)

SMz = Mz+Hx.(Dl+T)








= 14.975



60&40 1230 207.93 0.01 22.83 12.82 10.28 _ _ _ O.K.

60&40 1204 156.33 0.20 22.77 9.97 7.40 _ _ _ O.K.

58&38 1203 173.93 13.70 0.57 11.22 8.11 _ _ _ O.K.

###

###

###

###

###

###

###

CHECK FOR STABILITY

Overturning :




P_all = 1.25 (P_net) + gs. X 3.5

Node no.

Load comb.


"Teng"



Sliding :

Uplift :

Upward force = Fb





Mrx Mrz

60&40 1230 0.01 311.90 31190 22.83 623.80 27.360&40 1204 0.20 234.50 1172.51 22.77 469.00 20.658&38 1203 13.70 260.90 19.04 0.57 521.80 915.4




Hm Hr Fb Fd

60&40 1230 10.5 114.4 10.9 0.0 174.0 N.A.60&40 1204 10.6 86.0 8.1 0.0 148.2 N.A.58&38 1203 3.5 95.7 27.2 0.0 157.1 N.A.






Node no.

Load comb.


Mrz/SMz

Node no.

Load comb.

F.O.S. = Hr/Hm

F.O.S. = Fd/Fb




V1 + Wp = P1 V2 + Wp = P2

M1 L M2

w

y2y1



P1 = V1 + Wp = 33.80 P2 = V2 + Wp = 33.90

M1 = Mz1 + Hx1.(Dl+T) = 11.5 M2 = Mz2 + Hx2. (Dl+T) = 11.2



207.93 22.83 38.46

30.85




y2 = SV / Lx - 6. SMz / Lx2 =





Shear force will be -0.02 at a distance x = 2.77 m


y = y2 + (y1 - y2). (Lx - x)/Lx

y = 34.9474 Mton / m


BM1 =






= 426


SF1 = 0.93



SF2 = 14.70



y. x2/2 + 0.5. ( y1 - y ). x2. 2/3 - P1. { x - ( Lx - L )/2 } - M1 - w. x2/2




1




= 5.3014




SF3 = 4.63 Mton / m




= -0.12


-0.10


= P'n. lcz

= -0.16


X Top 1.91 0.15 0.04 0.31 0.01 0.00 0.12X Bottom 4.93 0.41 0.12 4.90 0.17 0.05 0.20Z Top 0.10 0.01 0.00 0.16 0.01 0.00 0.12Z Bottom 4.48 0.37 0.10 4.63 0.16 0.04 0.20

Mton / m2


Mton / m2


= P_min - gs.Dw - ( gs -1.0 ).( Df - Dw )


Direc- tion

Tension at

B.M. (Mton-m/m)

Mu/bd2 (MPa)

pt (%) as per SP:16

S.F. (Mton/

m)

Vu/bd (MPa)

pt (%) as per SP:16

pt (%) reqd.



Face





= 3.70


= 33.90 = 33.9 Mton

= 0.32


= 1.25 O.K.

Direc- tion


100

Bar dia. (mm)

Spacing (mm)









61&41 1230 32 3.6 -0.35 0.15 6.7 32 3.1 -0.33 0.15 6.261&41 1203 23.2 0.13 -4 -15.67 0.17 23.1 -0.3 -4 -15.8 -0.461&41 1204 21.6 -3.2 -0.4 0.95 -6.3 21.7 -3.6 -0.4 0.9 -6.8

#####################


= 2.5= 1.6



= 0.55









Node no.

Load comb.


& soil ( m )











V Hx Hz Mx e Mz

61&41 1230 64 6.7 -0.68 0.3 0.000 12.961&41 1203 46.3 -0.17 -8 -31.47 0.003 -0.1161&41 1204 43.3 -6.8 -0.8 1.85 0.003 -12.98









Node no.

Load comb.

2.lx.lz.Dl.gc =

Lx.Lz.T.gc =


SV = V+Wp+Wf+Ws-Fb

SMx = Mx+Hz.(Dl+T)

SMz = Mz+Hx.(Dl+T)








= 14.975



61&41 1230 207.09 0.30 12.90 11.95 10.50 _ _ _ O.K.

61&41 1203 189.39 31.47 0.11 13.62 6.90 _ _ _ O.K.

61&41 1204 186.39 1.85 12.98 11.00 9.21 _ _ _ O.K.

###

###

###

###

###

###

###

CHECK FOR STABILITY

Overturning :




P_all = 1.25 (P_net) + gs. X 3.5

Node no.

Load comb.


"Teng"



Sliding :

Uplift :

Upward force = Fb





Mrx Mrz

61&41 1230 0.30 315.81 1052.69 12.90 626.44 48.661&41 1203 31.47 288.81 9.18 0.11 572.89 5208.161&41 1204 1.85 284.24 153.64 12.98 563.82 43.4




Hm Hr Fb Fd

61&41 1230 6.7 113.9 16.9 0.0 175.1 N.A.61&41 1203 8.0 104.2 13.0 0.0 166.3 N.A.61&41 1204 6.8 102.5 15.0 0.0 164.7 N.A.






Node no.

Load comb.


Mrz/SMz

Node no.

Load comb.

F.O.S. = Hr/Hm

F.O.S. = Fd/Fb




V1 + Wp = P1 V2 + Wp = P2

M1 L M2

w

y2y1



P1 = V1 + Wp = 23.20 P2 = V2 + Wp = 23.10

M1 = Mz1 + Hx1.(Dl+T) = -15.67 M2 = Mz2 + Hx2. (Dl+T) = -15.67



189.39 0.11 31.32

31.29




y2 = SV / Lx - 6. SMz / Lx2 =







y = y2 + (y1 - y2). (Lx - x)/Lx

y = 31.3034 Mton / m


BM1 =






= 426


SF1 = 4.42



SF2 = 9.20



y. x2/2 + 0.5. ( y1 - y ). x2. 2/3 - P1. { x - ( Lx - L )/2 } - M1 - w. x2/2




1




= 6.1513




SF3 = 4.91 Mton / m




= -0.57


-0.43


= P'n. lcz

= -0.70


X Top 7.51 0.60 0.17 1.45 0.05 0.00 0.17X Bottom 3.32 0.27 0.08 3.02 0.11 0.02 0.20Z Top 0.43 0.03 0.01 0.70 0.02 0.00 0.12Z Bottom 4.62 0.38 0.11 4.91 0.17 0.05 0.20

Mton / m2


Mton / m2


= P_min - gs.Dw - ( gs -1.0 ).( Df - Dw )


Direc- tion

Tension at

B.M. (Mton-m/m)

Mu/bd2 (MPa)

pt (%) as per SP:16

S.F. (Mton/

m)

Vu/bd (MPa)

pt (%) as per SP:16

pt (%) reqd.



Face





= 3.70


= 32.00 = 32 Mton

= 0.30


= 1.25 O.K.

Direc- tion


100

Bar dia. (mm)

Spacing (mm)









40&60 1230 35.3 6.1 0.1 0.2 12.7 35.4 5.8 0.1 0.15 1340&60 1204 6.5 -5.9 -0.1 -0.2 -13.1 6.6 -6.1 -0.1 -0.2 -12.933&58 1203 16.9 -0.05 -1.6 -6.4 -0.5 16.9 -0.3 -1.8 -6.5 -0.2

#####################


= 2.5= 1.6


Friction between conc.= 0.55









Node no.

Load comb.


& soil ( m )











V Hx Hz Mx e Mz

40&60 1230 70.7 11.9 0.2 0.35 0.002 25.8340&60 1204 13.1 -12 -0.2 -0.4 0.010 -25.8733&58 1203 33.8 -0.35 -3.4 -12.9 0.000 -0.7









Node no.

Load comb.

2.lx.lz.Dl.gc =

Lx.Lz.T.gc =


SV = V+Wp+Wf+Ws-Fb

SMx = Mx+Hz.(Dl+T)

SMz = Mz+Hx.(Dl+T)








= 14.975



40&60 1230 212.14 0.35 25.83 13.26 10.31 _ _ _ O.K.

40&60 1204 154.54 0.40 25.87 10.07 7.10 _ _ _ O.K.

33&58 1203 175.24 12.90 0.70 11.21 8.26 _ _ _ O.K.

0 0 141.44 0.00 0.00 7.86 7.86 _ _ _ O.K.

0 0 141.44 0.00 0.00 7.86 7.86 _ _ _ O.K.

###

###

###

###

###

CHECK FOR STABILITY

Overturning :




P_all = P_net + gs. Dw + ( gs - 1.0 ). ( Df - Dw )

Node no.

Load comb.


"Teng"



Sliding :

Uplift :

Upward force = Fb





Mrx Mrz

40&60 1230 0.35 318.22 909.19 25.83 636.4 24.640&60 1204 0.40 231.82 579.54 25.87 463.6 17.933&58 1203 12.90 262.87 20.38 0.70 525.7 751.0

Mininmum F.O.S. against overturning about Lz = 20.4 O.K.

Mininmum F.O.S. against overturning about Lx = 17.9 O.K.


Hm Hr Fb Fd

40&60 1230 11.9 116.7 9.8 0.0 176.7 N.A.40&60 1204 12.0 85.0 7.1 0.0 147.9 N.A.33&58 1203 3.4 96.4 28.2 0.0 158.3 N.A.






Node no.

Load comb.


Mrz/SMz

Node no.

Load comb.

F.O.S. = Hr/Hm

F.O.S. = Fd/Fb




V1 + Wp = P1 V2 + Wp = P2

M1 L M2

w

y2y1



P1 = V1 + Wp = P2 = V2 + Wp =

M1 = Mz1 + Hx1.(Dl+T) = M2 = Mz2 + Hx2. (Dl+T) =


Ordinate of distributed reaction below foundation :

212.14 25.83 39.66

31.05




y2 = SV / Lx - 6. SMz / Lx2 =





Shear force will be -37.50 at a distance x = 3 m


y = y2 + (y1 - y2). (Lx - x)/Lx

y = 35.3573


BM1 =






= 426


SF1 = -34.18

Shear force per unit width of footing = SF1 / Lz = -11.39 Mton/m


SF2 = 16.47



Mton / m2

y. x2/2 + 0.5. ( y1 - y ). x2. 2/3 - P1. { x - ( Lx - L )/2 } - M1 - w. x2/2




1




= 5.7397




SF3 = 5.30 Mton / m

Analysis along Z - axis for tension at top :



= -0.42


-0.38


= P'n. lcz

= -0.56


X Top 21.98 1.77 0.54 -11.39 -0.40 0.18 0.54X Bottom 5.64 0.47 0.13 5.49 0.19 0.06 0.20Z Top 0.38 0.03 0.01 0.56 0.02 0.00 0.20Z Bottom 5.23 0.43 0.12 5.30 0.19 0.06 0.20

Mton / m2


Mton / m2


= P_min - gs.Dw - ( gs -1.0 ).( Df - Dw )


Direc- tion

Tension at

B.M. (Mton-m/m)

Mu/bd2 (MPa)

pt (%) as per SP:16

S.F. (Mton/

m)

Vu/bd (MPa)

pt (%) as per SP:16

pt (%) reqd.



Face

X Top 2289.8 16 200 1004.8X Bottom 852 16 200 1004.8Z Top 852 12 125 904.32Z Bottom 852 16 200 1004.8



Periphery of punching shear ( Bo ) in m = 2. ( lx + d ) + ( lz + d )

= 2.58


= 35.40 = 35.4 Mton

= 0.48


= 1.25 O.K.

Direc- tion


100

Bar dia. (mm)

Spacing (mm)




Sheet2

Page 55

Node no. P_max P_mod V1 V2 M1 M2 y1

52&32 1203 12.06 _ 25.1 24.6 -1.33 0.47 34.55

4&1 1230 13.08 _ 47.6 47.1 22.57 21.71 45.58

14&11 1204 10.83 _ 20.7 20.4 -22.15 -22.95 37.89

14&11 1171 13.81 _ 47.9 47.1 0.52 0.03 41.19

14&11 1203 11.52 _ 20.4 20.4 -0.16 -1.17 33.40

24&21 0 0.00 0.00 0 0 0.00 0.00 0.00

24&21 0 0.00 0.00 0 0 0.00 0.00 0.00

24&21 0 0.00 0.00 0 0 0.00 0.00 0.00

34&31 0 0.00 0.00 0 0 0.00 0.00 0.00

34&31 0 0.00 0.00 0 0 0.00 0.00 0.00

Load comb.

Sheet2

Page 56

y2

34.52

36.34

28.72

40.82

33.13

0.00

0.00

0.00

0.00

0.00

lx lx

X(+) lz Hx1 lz Hx2 Lz

Mx1 Mx2Mz1 Mz2

Z(+) Hz1 Hz2

L

Lx

PLAN

V1 V2

LOAD POINT Mz1 Mz2

Hx1 Hz2

F.G.L.

DwDl G.W.T.

Df

T

LEVELLING CONCRETE

ELEVATION


Design of Isolated Foundation :

Nomenclature used for design of Isolated Foundation

Axis directions:X Direction : Along length of the buildingZ Direction : Along width of the buildingY Direction : Vertical direction

Hz

t

Ix

Hx

Mx

Mz

IzLz

Lx

Mz

Hx

DI

Df

T

PLAN

ELEVATION

FGL

Column

EL = -0.500m

Dw

NGL

Ds V

A Vertical Horizontal Horizontal Moment GNode L/C Fy kN Fx kN Fz kN Mx kNm Mz kNm

3101 1 F -1181.562 87.153 118.095 533.903 -462.2393101 2 S 803.868 125.818 -0.001 -0.004 -473.9143102 1 F 551.073 138.209 53.439 220.847 -470.263102 2 S -1010.165 99.394 0 0 -469.763

Sheet4

Page 60

2 11.2 22.412 12 144

6 9.36 56.162 11.2 22.41 24 246 25.08 150.483 17.92 53.761 19.6 19.6

492.8 0.858537574 1.164773

Documents

Combined Footing _type2