Rcc tank

PHED PAKISTAN

16

RCC WATER TANK ENGR.Hammad Bashir(Civil Engineer)

ENGR.HAMMAD BASHIR GONDAL

WEBSITE:http://www.hammadjatt.weebly.com

HERE IS ONLY EXAMPLE OF RCC WATER TANK.

FOR DETAIL OF RCC STRUCTURE YOU CAN CONTACT ME

CELL NO: +92343-0817733

+92311-4248781

Email : [email protected]

http://www.hammadjatt.weebly.com/



Steel For faces in contact with water 16 ksi

For faces away from water 18 Ksi

Concrete For faces in contact with water 600 psi

For faces away from water 750 psi

Compressive strength of concrete 3000 psi

Safe shearing strength of concrete 60 psi

[ACI building code and almost all modern codes permits member

One third greater than usual stresses when the applied stresses

Are due to Wind Are earthquake forces]

DESIGN PARAMETERS

Wind velocity 100 mph

Wind force 34 psf

Seismic Factor g/20




Safe Bearing Capacity 0.50 psf

Depth of footing from EGL 7.00 ft from EGL

[Over 3 feet thick structural fill Pad if Pit Run Gravel

Or Sub Base Material Compacted to 95% modified AASHTO]

Total depth of Excavation from EGL 10 ft

Height of TANK 50 ft

[Geotechnical expert has recommended

1-The use of Sulphate Resisting slag/cement,

2-Dewatering should be carried out till Final Setting time of Cement,

Instructions contained should strictly be followed]

SIZING OF TANK

Internal diameter of bowl 20 ft

Water height 10.25 ft

Free board 1.00 ft

Gross height 11.25 ft

Wall thickness of bowl 7 ft

Volume of Water 25000 gallons

REFERENCES ACI working stress method

R.C.C designed by Everards and Tanner




Design Handbooks by Reynolds

Computer software PCA column

THICKNESS 5 inch a= 1.29

c/c Diameter (D) 21.2 ft d= 4.25 inch

Design Load 0.085 ksf

Moment (M) = W*D^2/32 1.19 k-ft

Steel reqd = M/a*d 0.22 in2

Provide #3@6”c/c both ways

Weight of water (W) 0.0624 k/cft

Wall thickness 7.00 inches

INSIDE Diameter 20.00 ft

Water Depth 10.25 ft

Wall Height (H) 11.25 ft

H/D 0.56




H/T 19.29

Corresponding to these values of H/D And H/T

F = 0.011

K1=0.37

K2= 0.63

Vertical Reinforcement Maximum moment in WALL (M) =F*W*H^3 0.98 k-ft a=1.13

(tension outside) d=5.75 inch

Vertical Steel (M/a*d) = 0.15 in2 fs=16ksi

Provide #4@12”c/c outer Face

Inner Face moment is negligible

Provide #4@12”c/c inner Face

Circular Reinforcement Maximum Circumferential Tension (T) = 0.5 W*H*D*K2 4.42 k

Horizontal Steel (Hoop tension) = T/fs 0.28 in2

Distribute on Each Face 0.4 in2

Provide #4@10”c/c Each Face

1.




SLAB THICKNESS 10 INCH

LOADING

SELF WEIGHT OF SLAB 0.125 K/sft

Weight of Water 0.640 k/sft WALL H=11..25 FT

Plaster and Mosaic 0.012 k/sft WALL T=7 INCH

Total UDL (W) 0.777 k/sft OUTER D= 21.2 FT

ROOF-W= 0.085 lb/ft

POINT LOAD AT FREE END OF SLAB Roof slab 0.45 k Wall 7” thick 0.98 k Total LOAD (P) 1.43 k

CANTILEVER PORTION

Moment (-ve) 4.42 k-ft

Steel Area 0.46 in2

Canti-L = 2ft

c/c-D1 = 16 ft

c/c- R = 8 ft

a = 1.13

d = 8.5




Provide #6@6”c/c

Moment (-ve) 4.14 k-ft

Steel area 0.43 in2 Moment (+ve) 5.52 k-ft Steel Area 0.57

Provide #6@8”c/c

Ref. table XII-PCA

DISTRIBUTION STEEL

0.15% OF CROSS SECTIONAL AREA 0.18 Inch2

Provide #4@12” c/c




BEAM DIMENSIONS 15” X 22”

LOAD CALCULATIONS ROOF 29.99 K WALL 63.62 K BASE SLAB 44.10 K WALK WAY 13.00 k BASE BEAM 9.42 k WATER 215 K Total 375.13 k

Perimeter 50.24 ft Load / ft-Run (W) 7.47 k/ft

MOMENTS CALCULATED BY FORMULA

M-ve 44.52 k-ft

M+ve 22.51 k-ft 22.51 M-ve 4.50 k-ft 4.50 k-ft

STEEL AREA POSITIVE 1.68 INCH2

Provide 4#6bars

Height h =11.25 ft

Wall t = 0.58 ft

Outer dia = 21.2 ft

c/c d = 20.58 ft

Roof w = 0.085 lb/ ft

Slab

Cantilever l = 2 ft

C/c d1= 16 ft

Thick t =10 inch

Radius =8

k1 =0.089

k2=0.045

k3=0.009

a= 1.29

Beam d =20.5




Applied shear V 27527.60 lb

Carried by CON VC 18526.72 lb

Spacing of #3 bars 9.02 in-c/c

Provide #3@6”c/c

COLUMN DIMENSIONS 12” x 15”

Load from Ring

Beam

62.52 k

Brases 5.84 k

Landing 3 k

Total/col 82.05 k

Total 492.27 k

Fc’ = 3 ksi

L = 7.37 ft

L’ = 3.96 ft

Beam b = 15 in

Beam d = 20.5 in

Fs = 18 ksi

COLUMN 6 no

W= 375.13 K

b = 1ft

d = 1.25 ft

h = 57 ft

Brace 5 no

b = 0.83 ft

d = 1.25 ft

l = 7.5 ft




Wind Analysis:

Wind:

Speed = 100 mph

Pressure = 0.034 ksf

Constant Wall = 0.7

Wall

L = 21.6 ft

H = 11.75 ft

Beam

d = 1ft

l = 17.5 ft

Column

L =10ft

H =50ft

B = 1ft

No =6

Exp area =5.5 ft

H = 1.25 t

L = 17 ft

No = 4 no




SEISMIC FORCE (F)

= g/20 24.61

Seismic Force Control the design structure

Shear in Column = V = F/6 4.10

Column Moment = v x L /2 20.51 k-ft

Column Load 82.05 k

Column Size = 12” x 15”

Steel = 6#6 (2.64 in2)

Rings #3@9”c/c

MEMBER EXPOSED AREA

WIND FORCE(F)

LEVER ARM -ft

MOMENT k-ft

Wall 253.8 6.04 64.33 388.58

Beam 17.5 0.42 57.58 23.98

Column 275 9.35 32.58 304.62

Braces 85 2.89 28.58 82.60

Total 18.70 799.78




SIZE 9” X 15”

MOMENT = 41.02 K-ft

Steel Area = 1.73 in2

Provide 5#6

SHEAR CHECK

Applied shear = 10255.68 lb

Shear stress = 84.41 psi ok

Carried by concrete = 1.1 √𝑓𝑐 bd

Steel using

Provide #3@10”c/c

Load through column 492.27

Wind moment 799.78 k-ft

Outer dia of raft 30.50

Inner Dia of raft 0.00 raft

Moment of inertia 42456.97 ft^4

Modulus of section 2784.06 ft^3

Area of footing 730.25 ft




Self weight of footing 115.01 k

Max stress in soil 1.12 ksf = 0.50 tsf

stress in Soil 0.96 ksf

Moment 20.31 k-ft

steel area 0.85 in^2

Provide #6@6”c/c

Provide #6@9”c/c

Provide 7#6

Provide #4@6”

DESIGN OF RAFT SLAB

FOUNDATION SLAB B/W RING BEAM

FOOTING RING BEAM

SHEAR CHECK REINFORCEMENT






