Transformer Foundation Design

EMPLOYER :

POWER GRI GRI D CO COMPANY MPANY OF BANGLADESH BANGLADESH LI MI TED TED ( PGC PGCB ) P GCB / D AN A N I D A/ A/ 1 CONTRACT CONTRACT N O. : PG DESI DESI GN-BUI LD AN D TURNKEY CONTRAC CONTRACT T FOR CONSTRUCTI ONSTRUCTI ON OF 1 3 2 k V J OY OY D EV EV P UR UR - K A B I R PU PU R - T A N GA GA I L T RA RA N SM SM I SSI O N L I N E PROJECT TI TLE : :

D e si si g n Ca C a l c u l at a t i o n f o r Fo u n d a t i o n o f A u t o T r a n s f o r m e r D O CU M EN T N O . :

SU B M I T T A L N O . :

JDP/A26/001

S EC ECT I O N : 1 2 , B u i l d in in g a n d c i v ili l e n g i n e e r i n g w o r k s

DESI DESI GNED BY : Md. Giasuddin

CH ECK ED B Y :

A P P R O V ED B Y :

R EV . N O . :

M A N U F A CT U R ER :

DATE :

19 Nov '05

Paper Size A4

E:\PROJECTS FOR EXECUTION\Joydevpur - Kabirpur Tangail OHL\Joydevpur Substation\Design Calculation\Static Cal of Foundation For Auto Transformer

CONTRACTOR : M TH

AA R D A A// S - LI LI N D P RO RO A / S JV JV J G AA

I D :

r o e s u , n o i t c u d o r . p n e e R d d . i n b i r e r o e f y h t l t c n i r o i t a s i m r y t o i f r n o i e h t h t u a d s n s a e t r p n x e e m t u u c o o t d h i s i w h s t e n i t i r s a t p h d g r i i r h l l t a o e t v r e r e u s s e o r l c e i s W d

EMPLOYER :

POWER GRI D COMPANY OF BANGLADESH LI MI TED ( PGCB ) CONTRACT N O. : PGCB / D AN I D A/ 1

DESI GN-BUI LD AN D TURNKEY CONTRACT FOR CONSTRUCTI ON OF 1 3 2 k V J OY D EV P UR - K A B I R PU R - T A N GA I L T RA N SM I SSI O N L I N E PROJECT TI TLE : :

D e si g n Ca l c u l at i o n f o r Fo u n d a t i o n o f A u t o T r a n s f o r m e r DOCUM EN T N O. :

SUBM I TTA L N O. :

JDP/A26/001

S ECT I O N : 1 2 , B u i l d in g a n d c i v il e n g i n e e r i n g w o r k s

DESI GNED BY : Md. Giasuddin

CH ECKED B Y :

A PPROV ED BY :

REV. N O. :

M A N UFA CTURER :

DATE :

19 Nov '05

Paper Size A4

E:\PROJECTS FOR EXECUTION\Joydevpur - Kabirpur Tangail OHL\Joydevpur Substation\Design Calculation\Static Cal of Foundation For Auto Transformer

CONTRACTOR : M TH

J G AA R D A/ S - LI N D P RO A / S JV

I D :

r o e s u , n o i t c u d o r . p n e e R d d . i n b i r e o r f e y h l t t c n i r o i t a s i m r y o t i f n r o i e h t h u t a d s n s a e t r n p e x e m t u u c o o h d t i s w i h s t e i n t i r a s t p h d g r i r i h l t l a o e t v e r r e u s s e o r l c e i s W d

MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station 1. GENERAL 1.1 Considerations :

a) Raft foundation is considered for a 132kV Transformer. b) The bottom of the r aft is at a depth of 1.0m from existing ground surface. 2

c) Soil bearing capacity is considered 90.04 kN/m minimum value from BH-4, BH-5 & BH-7. d) The Top of bund wall is 200mm above the finished switchyard surface level.

1.2 Soil Data: Allowable bearing capacity of soil is considered : 90.04 kN/sqm Unit weight of soil : 17.94 kN/cum. Frustum angle : 15.00 Deg. Water Table from EGL : 2.50 m

1.3 Material Properties : Concrete………………...…fc'= 20 N/mm2 Reinforcing Steel…………..f y = 415 N/mm2 Concrete Clear Cover……….= 60 mm Unit Weight of Concrete…….= 24.0 kN/cum. 2. DESIGN DATA AND FOUNDATION GEOMETRY : ( Reference Dwg no. 56.20.3-03-3537) Transformer's Length = 6.80 m Transformer's Width = 5.10 m Height of Transformer = 5.00 m Total Weight of Tx. ( with Oil ) = 72,000 Kg Weight of Oil = 19,000 Kg Density of Oil = 840 Kg/cum. Total volume of oil = 22.62 Cum Pit volume reqd. below the stone ( 125% of oil vol. ) = 28.27 Cum Inside length of pit considered = 7.80 m Inside width of pit considered = 5.80 m Surface area of the pit = 41.47 sqm. Width of Tx. Supporting Pedestal = 2.68 m Length of Tx. Supporting Pedestal = 3.89 m Area of Tx. Supporting Pedestal = 10.4 sqm. Net surface area of the pit = 31.0 sqm. Average Depth required = 0.9 m Provided depth below Grating = 0.90 m Thickness of grating = 0.05 m Thickness of gravel layer on top of grating = 0.225 m Free height above gravel top = 0.05 m Max. height of pit wall above base slab = 1.225 m Center of Tx .

Ce n t e r o f Foundation

i g n By : M d . Gi a s u d d i n

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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station Ce n t e r o f Foundation

3. LOAD CALCULATION

Transformer Length, L = 6.80 m Transformer Width, B = 5.10 m Transformer Height above top of Pedestal, H = 5.00 m Total weight of Transformer ( with oil ) = 720.00 kN 3.1 Wind load calculation - as per BNBC

Maximum wind velocity , Vb = 160.0 km/hr Height of top of transformer from FSYL = 5.20 m

( Specified in the Contract specification) ( Ref. Bangladesh National Building Code 1993, Chapter 2;Page 6-33)

q z = c cc I c z v 2 b For exposure B , Cz at Top = 0.85 For exposure B , Cz at Bottom = 0.801 Velocity to Pressure conversion coefficient, Cc = 4.72E-05 Structure Importance Factor CI = 1.25

q z = 1.284 kN/m2 = 1.210 kN/m2

Design Wind Pressure, pz = c Gc pq z

; at Top ; at Bottom ( Ref. Bangladesh National Building Code 1993, Chapter 2;Page 6-34)

L/B = 1.33 H/B = 0.98 , p .

-

Gust Co-efficient, CG = 1 .30

Design Wind Pressure, p z = 1.335 kN/m2 = 1.258 kN/m2 Average Pressure , Pz = 1.29671 kN/m2 ∴ Force results from Wind = 1.297*6.8*5.1 = 44.97 kN

; at Top ; at Bottom

3.2 Seismic load calculation - as per BNBC

Design Base Shear is given by :

V

( Ref. Bangladesh National Building Code 1993, Chapter 2;Page 6-53) ( for Zone 2 ) ( with essential Facilities ) ( For RCC wall System )

ZICW =

R

Where, Z = Seismic Zone Co-efficient = 0.15 I = Structure Importance Factor = 1.25 R = Response Modification Coefficient = 6 C = Numerical coefficien t system is given by : C =

1.25S T

2

3

S = Site coefficient for soil characteristics = 1.5 T = Fundamental period of vibration is given by : T = Ct ( hn )

3

4

Ct = 0.049

( For all type of non braced RCC structure )

hn = 5.00 m T = 0.164 Sec C = 6.262 W = Total Seismic dead load =Transformer Weight = 720.00 kN Design base shear V = 140.90 kN 4. SOIL STABILITY CHECK

828.0 kN

4.1 Check for Soil Bearing Capacity :

Weight of each Transformer with 15% impact = Weight of Transformer supporting Pedestal = Length of foundation pad = Width of foundation pad = Thickness of foundation pad =

828.00 kN 306.50 kN 8.800 m 6.800 m 0.300 m

140.0 kN

CL of Foundation

Load Application on Foundation


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MT H JGAARD A/S - LINDPRO A/S JV

CL of Found a t i o n

Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station Weight of Pad = 430.85 kN Width of Bund Wall = 0.200 m Total Length of Bund wall = 28.540 m Height of Bund wall = 1.225 m Weight of Bund wall = 167.82 kN Total area of the Yard within bundwall = 41.47 m2 Area of Tx. supporting Pedestal = 10.43 m2 Net area to be filled with gravel = 31.04 m2 Thickness of Gravel = 0.225 m Weight of gravel = 111.76 kN

Load Application on Foundation

Total Vertical Load = 828+306.5 +430.85+167.82+111.76 = 1844. 93 kN Maximum Moment at base due to Max. Horizontal Load =140.9*1.525 = 214.87 kN.m Eccentricity for Horizontal load = 214.87/1844.93 = 0.116 m Net Eccentricity = 0.116+0.600 = 0.716 m Q = Fzb = 1844.93 kN kNs A = LxB = 59.84

2

m

e = el = 0.716 m

m

L /6 = 1.467

>e

6e (1+ ) A L Q 6e = (1) A L

So;q max = and;q min

Q

qmax = 43.54 kN/m2 Gross allowable soil pressure = 90.04 + γsDf = 107.98 kN/m2

So it's OK.

Net Upward Pressure = 43.54-γ'sDf = 35.60 kN/m2 4.2 Check for Settlement : Settlement of a Soil layer is given by :

S =

cc

1 + e0

H log10

p0 + Δp p0

Where, Cc = Compression Index = 0.258

From soil test report of BH-4.

e0 = Initial Void ratio = 0.989

From soil test report of BH-4. From soil test report of BH-4.

H = Thickness of the Soil Layer = 5.00 m

p0 = The original Soil Pressure at the mid point of the layer = γ∗H/2 = 45.00 kN/m2 Δ p = Change In Pressure = qmax - γDf = 25.60 kN/m2

S = 0.1269 ft. = 1.524 inch. Which is less than 2.0" , so OK. 5. STRUCTURAL DESIGN 5.1 Design of Pit Wall :

Angle of repose for backfilled soil, φ = 0.00 Deg Coefficient of earth pressure , Ka = ( 1-sin φ ) / ( 1-sin φ ) = 1.00 Unit weight of soil = 17.94 kN/cum Height of soil at toe side above base = 0.000 m Height of soil at heel side above slab = 0.700 m PL above heel side soil = 0.200 m Thickness of stem = 0.200 m Thickness of base slab = 0.300 m Superimposed live load at heel side = 10.00 kN/sqm Applied Loading : Unit Weight of Gravel Fill = 16 kN/cum. Unit Weight of Brick = 19 kN/cum. Unit Weight of Sand Fill = 15 kN/cum. 2

Pressure due to Backfill P1= 1/2*K pγh *1.0 = 4.40 kN


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( Per meter of width )

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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station ( For Backfill φ is considered 0 Degree ) K a = ( 1-Sinφ )/( 1+Sinφ ) = 1.0 Pressure due Surcharge load P2 =10.0+ ( 0.175*16+0.075*19+0.075*15)*0.7 = 13.75 kN ( Per meter of width ) So Moment about point A = 4.41*0.233+13.75*0.35 = 5.835 kN.m ( Per meter of width ) Factored Moment = 5.838*1.5 = 8.752 kN.m " Let us check with minimum reinforcement. As per ACI code, Ratio of minimum reinforcement ( in SI unit) is given by =1.4/fy

ρmin= 0.003373494 ρf y ⎛ M u =φρf y bd 2 ⎜1-0.59 f'c ⎝ ∴

⎞ ⎟...;Where ⎠

Mu

d=

φρf y b(1-0.59

ρf y

fc'

φ

= )

= 0.9

; d Provided =200-100-10/2= 95 mm; OK

85 mm

5.1.1 - Reinforcement Calculation : Vertical Reinforcement

Mdes =Mu/0.9 = 9.725 kN.m Assuming depth of stress block, a = 6.94 mm Area of steel, As = M*1000000/(0.9*fy*(d-a/2)) = 284.47 mm2 (Ref. -Design of concrete structure, By-Nilson & Winter,Page 83 ,10th Ed. ) Check for a a = As*fy/(.85*fc'*b) = 6.94 mm Consideration is OK, So As = 284.47 mm2/m As per Code Min Rebar Required = 0.004bt = 400.00 mm2/m Consider bar Size = 10.0 mm So Nos. of Bars = 5 Nos Spacing = 200.00 mm Provide φ 10mm @ 200mm at both face of the wall. Horizontal Reinforcement : As per Code Min Rebar Required = 0.002bt = 400.00 mm2/m Consider bar Size = 10.0 mm So Nos. of Bars = 5 Nos Spacing = 1000/5 = 200.00 mm Provide φ 10mm @ 200mm at both face of the wall. Check for shear : Shear force , V = 18.14 kN Factored shear , Vu = 27.21 kN Where, b= 1000 mm d = 95 mm So, vc= Vc/bd = 0.286 N/mm2 AS per ACI Shear Stress applied to concrete should be less than

0.17

c

'

2

N/mm ; In present case which is coming 0.76 Mpa.

This is much greater than applied stress so consideration is quite Ok. 5.2 Design of Transformer Supporting Pedestal : ( Reference Dwg no. 56.20.3-03-3537)

Length of Pedestal = 3.890 m Width of Pedestal = 2.680 m Hight of Pedestal = 1.225 m Weight of Pedestal = 306.50 kN Total Weight of Tx. ( with Oil ) = 720.00 kN Design Loads:

Compression =720.0+306.5 = 1026.50 kN Moment M = 172.6025

Max. or Min. stress on the section =

σ

max/min

=

P A

±

Mc I

3 I = bh /12 = 6.24E+12 mm4 Maximum stress on the section = 0.06 Mpa, Compressive

Stresse is within acceptable limit, so no rebar is r equired from structural point of view.


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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station 2

2

But as per code Minimun Rebar = 0.0018*Ag = 0.0018*3890*2680 mm . = 18766 mm . So Use 94 nos. of dia 16mm Bar for Vertical Reinforcement. Use dia 10mm bar @ 200 mm c/c for tie. 5.3. Design of Base Slab Foundation Layout Ce n t e r o f Tx .

Ce n t e r o f Foundation

5.3.1 Check for Punching of the Base : Base Thickness, t = 300 mm Clear Cover = 60 mm Consider Max Bar size = 20 mm d = 300-60-20/2 = 230 mm Punching Perimeter = (2680+3890)*2 = 13140 mm Punching Area = 13140*230 = 3022200 mm2 Vertical Forces = 1026.50 kN Punching stress developed by Tx. = 1026.5*1000/ 3022200 = 0.340 Mpa

AS per ACI Shear Stress applied to concrete should be less than

0.33

f c '

Mpa

In present case which is coming 1.48 Mpa. So OK. 5.3.2 Bottom Reinforcement Along Long Direction : For right side Net Upward Pressure by soil = 35.60 kN/m2 Max Moment Developed at Pedestal face at Bottom = 35.6*3.055^2/2 = 166.147 kN.m/m Design moment = 170.42/0.9 = 184.607 kN.m/m Base Thickness, t = 300 mm Clear Cover = 60 mm Consider Bar size = 20 mm d = 300-60-20/2 = 230 mm

Assuming depth of stress block, a = 60.39 mm Area of steel, As = M*1000000/(0.9*fy*(d-a/2)) = 2473.73 mm2


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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station Check for stress block,a a = As*fy/(0.85*fc'*b) = 60.39 mm Consideration is OK, So As = 2473.73 mm2 Minimum reinforcement = 0.18 % = 540.00 mm2/m Consider bar Size = 20 mm So Nos. of Bars = 7.87 Nos Spacing = 127 mm

Say 120mm

For Left Side

Max Moment Developed at Pedestal face at Bottom = 35.6*1.855^2/2 = 61.257 kN.m/m Design moment = 61.257/0.9 = 68.063 kN.m/m Base Thickness, t = 300 mm Clear Cover = 60 mm Consider Bar size = 20 mm d = 300-60-20/2 = 230 mm Assuming depth of stress block, a = 20.23 mm Area of steel, As = M*1000000/(0.9*fy*(d-a/2)) = 828.76 mm2 Check for stress block,a a = As*fy/(0.85*fc'*b) = 20.23 mm Consideration is OK, So As = 828.76 mm2 Minimum reinforcement = 0.18 % = 540.00 mm2/m Consider bar Size = 20 mm So Nos. of Bars = 2.64 Nos Spacing = 379 mm

Say 240mm

5.3.3 Bottom Reinforcement Along Short Direction :

Net Upward Pressure by soil = 43.54 -γ'sDf = 35.60 kN/m2 Max Moment Developed at Pedestal face at Bottom = 35.6*2.16^2/2 = 83.057 kN.m/m Design moment = 83.057/0.9 = 92.286 kN.m/m Base Thickness, t = 300 mm Clear Cover = 60 mm Consider Bar size = 12 mm ( Bars to be placed on top of long Bars) d = 300-60-12/2-20 = 214 mm Assuming depth of stress block, a = 30.34 mm Area of steel, As = M*1000000/(0.9*fy*(d-a/2)) = 1242.69 mm2 Check for stress block,a a = As*fy/(0.85*fc'*b) = 30.34 mm Consideration is OK, So As = 1242.69 mm2 Minimum reinforcement = 0.18 % = 540.00 mm2/m Consider bar Size = 12 mm So Nos. of Bars = 10.99 Nos Spacing = 91 mm

Say 90 mm

Calculation For Bar Curtailment

Max Moment Developed at 0.75 m far from Pedestal face at Bottom = 35.6*1.41^2/2 = 35.392 kN.m/m Design moment = 35.392/0.9 = 39.325 kN.m/m Base Thickness, t = 300 mm Clear Cover = 60 mm Consider Bar size = 12 mm ( Bars to be placed on top of long Bars) d = 300-60-12/2-20 = 214 mm Assuming depth of stress block, a = 12.37 mm Area of steel, As = M*1000000/(0.9*fy*(d-a/2)) = 506.64 mm2 Check for stress block,a a = As*fy/(0.85*fc'*b) = 12.37 mm Consideration is OK, So As = 506.64 mm2 Minimum reinforcement = 0.18 % = 540.00 mm2/m Consider bar Size = 12 mm So Nos. of Bars = 4.77 Nos


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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station Spacing = 209 mm Say 180 mm Point of curtailment = 750+(12 times dia of bar ; i.e 12*12 = 144mm use 250mm) 250 = 1000mm from face of Padestal.

5.3.4 Top Reinforcement Calculation along both direction :

Max Hogging Moment Developed = 35.6*( 3.0550.40)^2/8 = 31.368 kN.m/m Design moment = 27.165/0.9 = 34.854 kN.m/m Base Thickness, t = 300 mm Clear Cover = 60 mm Consider Max Bar size = 12 mm d = 300-60-12/2 = 234 mm Assuming depth of stress block, a = 9.95 mm Area of steel, As = M*1000000/(0.9*fy*(d-a/2)) = 407.45 mm2 Check for stress block,a a = As*fy/(0.85*fc'*b) = 9.95 mm Consideration is OK, So As = 407.45 mm2 Minimum reinforcement = 0.18 % = 540.00 mm2/m Consider bar Size = 12 mm So Nos. of Bars = 4.77 Nos Spacing = 209 mm 6. DESIGN OF GRATINGS

Say 200mm

Layout of Gratings :

Steel of Fy 275.0 Mpa shall be used for gratings. Main bar : 50X6 Flat Spacing of main bar : 30 mm c/c Secondary bar dia. = 12 mm


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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station Spacing of secondary bar : Thickness of gravel paving = Unit weight of gravel = Max span of main bar =

100 mm c/c 225 mm 16.00 kN/cum 1.698 m

6.1 Design of main bar :

Self weight of grating : 0.56 kN/sqm Self weight of gravel : 3.60 kN/sqm Assumed live load : 2.00 kN/sqm Total load per unit area = 6.16 kN/sqm Uniform Distributed Load per main bar = 0.185 kN/m Check for bending stress : 2

Max bending moment = 0.185*1.698 /8 = 0.067kN.m 2

Zxx of main bar = 6*50 /6 = 2500 mm3 Max bending stress = 0.067*10^6/2500 = 26.64 Mpa Allowable bending stress = 0.6*Fy = 0.6*275 = 165.00 Mpa Check for shear stress : Max shear force = 0.157 kN Max shear stress = 0.52 Mpa Allowable Shear stress = 0.346*Fy = 0.346*275 = 95.15 Mpa Check for max deflection :

; So OK.

; So OK.

Ixx of main bar = 6*50^3/12 = 62500 mm4 Modulus of elasticity of steel = 200000 Mpa 4

= = . Allowable Maximum deflection = l/325 = 5.22 mm

; So OK.

6.2 Design of grating supporting channel :

Max span of channel = 2.505 m Load from grating per channel = 6.16*2.505 = 15.431 kN/m Max bending moment , M = 12.104kN.m Max end shear, V = 19.327 kN Provide : ISMC 200 Check for bending stress :

Total depth, D = Sectional Area, A = r yy = Flange thickness, T = Web thickness, tw =

200 mm 2828 mm2 22.3 mm 10.40 mm 6.1 mm

Zxx = 182500 mm3 Ixx = 18251000 mm4 Leff / r yy = 2700/22.3= 112.33 3

When

703 X10

C b

F y

≤

l r

2 ⎡ F y l 2 ⎢ r Fb = ⎢ 3 − 10550 X 103 C b ⎢ ⎣

(

)

≤

3 3516 X10 C b

F y

⎤ ⎥ F ≤ 0.60F y ⎥ y ⎥ ⎦

2 Where C b = 1.75 + 1 .05 * ( M1 / M2) + 0.3( M1 / M 2)

Consider ends of channel are not to carry any moment so 2nd and 3rd term of the above equation can be ignored. So C b = 1.75 Bending Stress = M/Z = 12.1*10^6/182500 = 66.32 Mpa ∴ Fb = 0.535*275 = 147.13 Mpa > 66.32 Mpa ; So OK. Check for shear stress : Shear stress = V/A = 19.327*1000/2828 = 6.83 Mpa Allowable Shear stress = 0.346*Fy = 0.346*275 = 95.15 Mpa > 6.83 Mpa ; So OK.


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MT H JGAARD A/S - LINDPRO A/S JV Design of Transformer Foundation ; Joydevpur 132/33kV Sub-station Check for max deflection : 4

Max central deflection = 5wl /384EI = 2.17 mm Allowable Max. deflection = l/325 =2825/325 = 7.71 mm


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; So OK.

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M T H JGA A RD A / S - LI N D PRO A / S JV D e si g n o f T r a n sf o r m e r Fo u n d a t i o n ; J oy d e v p u r 1 3 2 / 3 3 k V Su b - s t a t i o n Co n t e n t s

Pa g e N o .

1. General

03

1.1 Considerations :

03

1.2 Soil Data:

03

1.3 Material Properties :

03

2 . D e si g n D a t a Fo u n d a t i o n Ge o m e t r y :

03

3 . L o a d Ca l c u l a t i o n :

04

3.1 Wind load calculation - as per BNBC

04


04

4 . S o i l S t a b i l i t y Ch e c k

04


04

4.2 Check for Settlement :

05

5 . St r u c t u r a l D e si g n :

05

5.1 Design of Pit Wall :

05

5.1.1 - Reinforcement Calculation :

06

5.2 Design of Transformer Supporting Pedestal :

06

5.3. Design of Base Slab

07

5.3.1 Check for Punching of the Base :

07

5.3.2 Bottom Reinforcement Along Long Direction :

07


08


09

6 . D e s i g n o f Gr a t i n g :

09


10


10

Giasuddin / BEL

Date : 19 Nov '05

M T H JGA A RD A / S - LI N D PRO A / S JV D e si g n o f T r a n sf o r m e r Fo u n d a t i o n ; J oy d e v p u r 1 3 2 / 3 3 k V Su b - s t a t i o n Co n t e n t s

Pa g e N o .

1. General

03

1.1 Considerations :

03

1.2 Soil Data:

03

1.3 Material Properties :

03

2 . D e si g n D a t a Fo u n d a t i o n Ge o m e t r y :

03

3 . L o a d Ca l c u l a t i o n :

04

3.1 Wind load calculation - as per BNBC

04


04

4 . S o i l S t a b i l i t y Ch e c k

04


04

4.2 Check for Settlement :

05

5 . St r u c t u r a l D e si g n :

05

5.1 Design of Pit Wall :

05

5.1.1 - Reinforcement Calculation :

06

5.2 Design of Transformer Supporting Pedestal :

06

5.3. Design of Base Slab

07

5.3.1 Check for Punching of the Base :

07

5.3.2 Bottom Reinforcement Along Long Direction :

07


08


09

6 . D e s i g n o f Gr a t i n g :

09


10


10

Giasuddin / BEL

Date : 19 Nov '05

Transformer Foundation Design

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