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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

1. Fundamentals

(1)

(a) Statical system for each tank

Fig. 1

For H = 1.5 m

The walls of the tank can be treated as cantilever , i.e., the total load acting in each

wall will be transmitted in vertical direction

For H = 4 m

Top horizontal beam should be used. In this case, the wall will be considered as twoway slab.

Horizontal strip at the sec.

of max. horizontal load

H

Vertical Sec.

Statical system inconjunction with

the loads

Vertical strip

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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

Fig. 2

Fig. 3

* If the tie is removed

Fig. 4

Statical system for

vl strip (Box. Sec)

Structural systemfor vl. strip

Tie

Statical system for vertical strip

H=2mThe walls of the tank can be considered as cantilever walls

H

Statical system for vl. Strip

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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

* H = 4 m

Top horizontal beam should be used.

Fig. 5

For large diameter tank, the part of floor with the length (L) with the wall adjacent to

it can be assumed as a retaining wall connecting to the central part.

* If the tank has sliding base, the wall and floor will be treated separately.

Fig. 6

b. Acting loads & case of loading

Fig. 1 to Fig. 4 are elevated tanks

Acting loads are: * own weight of concrete elements

* water load vl. Load on floor

lateral load on walls

* External lateral load wind pressure

Earthquake Excitation

- case of loading

1- Case of water load (No external lateral load)2- Empty tank and consider lateral load.

vl. Strip

Horizontal Strip vl. Strip in short dir.vl. Strip in long dir.

Treated as cantileverretaining wall H

L

Central part

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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

Fig. 5 is rest on soil tank

Acting loads are : own weight of tank: Water load

: Soil reaction

there is only one case of loading under the effect of all acting loads

Fig. 6 is under ground tank

Acting load are : - Own weight of concrete

- Weight of water

- Weight of soil above the tank

- Lateral earth pressure

- Lateral hydrostatic pressure due to ground

water.- Soil reaction below the tank

- Uplift force due to ground water

Case of loading

tank is full of water and no soil around tank (Check

bearing capacity of soil)

tank is empty and consider soil around tank (Check

uplift)

(2)

- The sections that labeled by (w.s) are water side sections.

- The sections that labeled by (a.s) are air side sections.

Case 1

Case 2Empty

w.s

a.s a.s

a.s

w.s

a.s

w.s

w.sw.s

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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

(3)sec. 1 Mu = 0.0

Nu = +150 kN

- Check of tensile stress for concrete.

Sec. 2 Mu =100 kN.m , Nu = 0.0 (water side sec.)

Water side section

o.kff

99.165.1

306.06.0f

1.65

cm50t])(

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MPa1.6500*100010*66.7

btM6

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cm637.5mm7.635360*0.85

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cu

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f

f

7/28/2019 Tank - 01

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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

Sec. 3 Mu = 100 kN.m & Tu = 10 kN

/m'105A'

/m'129or

/m'165use

cm9.75mm975826.0*460*360*75.0

10*100A

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cm6.8mm608826.0*460*360*85.0

10*100A

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f

MA

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mm460dmm500t&kN.m100

s

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MA

7/28/2019 Tank - 01

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Instructor: eng \ just for help Subject: Water Tanks2000-2001 Solved Examples

Sec. 4 Mu = 10 kN.m & Tu =150 kN

N/mm3.28f,1.45

mm5.9921.005

0.51200

)(

)(f1tt

N/mm005.1200*1000

10*6.7*6bt6M)(f

N/mm5.0200*1000

1000*100

A

T)(f

/f(M)f)(ff

mm200tuse

60100*6.0T0.6

mm4.591307.650

3050t

kN100

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150T&kN.m7.6

5.1

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mm

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kN5.3710.16

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kN150T&kN.m10M

o.kff

N/mm26.21.45

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