Thrust Block Design JNT450

8/10/2019 Thrust Block Design JNT450

1/15

SRIPADASAGAR PROJECT, STAGE II - PHASE I

JOGAPUR TO NEW TANK AT 450

Chainage 1979 mInternal Dia. of pipe 1.2 m

Pipe thickness 8 mm

External dia. of pipe 1.216 m

Test pressure 6.00 kg/cm

2

Horizontal deviation angle(q) 15.00 deg.

Cross sectional area of pipe 1.16 m2

Horizontal offset around Pipe 0.30 m

Vertical offset around Pipe 0.30 m

Width of the Block 1.80 m

Depth of the Block 1.80 m

Unit weight of Concrete 2.40 t/m3

Unit weight of Steel 7.85 t/m3

Unit weight of Water 1.00 t/m3

Soil density 1.8 t/m3

Saturated soil density 2.1 t/m3

Angle of internal friction (F) 30 Deg

Coeff. of active earth pressure (Ka) = (1-sinF)/(1+ sinF) 0.333

Coeff. of passive earth pressure (Kp) = (1+sinF)/(1-sinF) 3.000

+ 411.253 + 411.253

+ 410.353

2.70

+ 409.721 + 409.721

Fa Fp

1.17

h2

1.17 1.89 17.01 1.17WATER PRESSURE EARTH PRESSURE A + 408.553 EARTH PRESSURE

DIAGRAM ON U/s DIAGRAM ON U/s DIAGRAM ON D/s

WATER PRESSURE

DIAGRAM ON D/s

1.17 1.17

Case-I Neglecting soil support

Weight of Block/m = 4.99 t/m

Weight of Water/m = 1.131 t/m

Weight of Shell/m = 0.238 t/mTotal Weight, (W) = 6.36 t/m

Thrust (T) = 2 P A Sin ( / 2) = 17.71 t

H = 1.80

0.90

THRUST BLOCK AT KM 1.979

Soil

h1

B = 1.80

UPLIFT PRESSURE DIAGRAM

a

h3

T0 PIPE


2/15

T0 = W(b - B/3)/h1 = 2.119 t/m

L = T / To = 8.50 m

Case-II Considering the soil support

(i) Active Pressure:

0.48

Pa= Kah

Above RL + 409.721 , Pa= 0.60 h

Below RL + 409.721 , Pa= 0.70 h

Pa at 0.90 m = 0.48 t/m2

Pa at 2.70 m = 1.74 t/m2

Fa= 1.99 t

h3= (2a + b) x h

(a + b) x 3

h3= 0.729 m

(ii) Passive Pressure:

4.2912

Pp= Kph

Above RL + 409.721 , Pp= 5.40 h

Below RL + 409.721 , Pp= 6.30 h

PP at 0.90 m = 4.29 t/m2

PP at 2.70 m = 15.63 t/m2

Fp= 17.93 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.729 m

T0 =

= 15.033 t/m

Total Length (L) = 1.18 m

Case-III Considering At Rest Pressure on outer face0.715

P0=

Above RL + 409.721 , P0= 0.90 h

Below RL + 409.721 , P0= 1.05 h

Po at 0.90 m = 0.72 t/m2

Po at 2.70 m = 2.61 t/m2

F0= 2.99 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.729 m

T0 =

= 4.54 t/m


Size of Thrust Block 4.00 x 1.80 x 1.80 m

W (b - B/3) + F0h2h1

1.80

h1

2.61

sh (1 - sin)

1.74

1.80

1.80

15.63

W (b - B/3) + Fph2- Fah3


3/15

1 Check for Uplift [Empty Condition]

Uplift = 1.168 x 1.8 x 4 x 1 = 8 t

Self weight of block + weight of pipe + weight of overburden soil

(( 4 x 1.8 x 1.8 - 4 x PI x 1.216 ^ 2 / 4 ) x 2.4) + ( PI x 1.2 x 0.008 x 4 x 7.85 ) + (4 x 1.8 x 0.9 x 1.8)

= 33 t

Uplift < Self weight of block + weight of pipe + weight of overburden soil

Pipe is safe against uplift

Self weight of block + weight of pipe + weight of overburden soil + weight of water in the pipe

(( 4 x 1.8 x 1.8 - 4 x PI x 1.216 ^ 2 / 4 ) x 2.4) + ( PI x 1.2 x 0.008 x 4 x 7.85 ) + (4 x 1.8 x 0.9 x 1.8) +

4 x PI x 1.2 ^2/4 x 1 = 37 t

2 Check for stresses :

TF0 18.16

11.95 h2 W h = 0.90 m

A

b

0.90 U

Taking Moments about A

M @ A = 0 :

L.A. = [W- U]b+F0h2-T h

W-U

= (( 37.09 - 8.41 ) x 0.9 + 11.95 x 0.73 - 17.71 x 0.9 ) / ( 37.09 - 8.41 )

= 0.648 m

e = b/2 - L.A = 1.8 / 2 - 0.65 = 0.252 m

B/6 = 0.300

e < B/6 No Tension

p = P/A( 1 6e/B)

pmax = ( 37.09 - 8.41 ) / 7.2 x ( 1 + 6 x 0.25 / 1.8 ) = 7.33 t/m2

pmin = ( 37.09 - 8.41 ) / 7.2 x ( 1 - 6 x 0.25 / 1.8 ) = 0.64 t/m2

3 Check for sliding

Coeff. of friction available = (T - F0 )/ W = ( 17.71 - 11.95 ) / 37.09

= 0.155


4/15


5/15

T0 = W(b - B/3)/h1 = 2.119 t/m

L = T / To = 27.00 m



0.51

Pa= Kah

Above RL + 395.639 , Pa= 0.60 h

Below RL + 395.639 , Pa= 0.70 h

Pa at 0.90 m = 0.51 t/m2

Pa at 2.70 m = 1.77 t/m2

Fa= 2.04 t

h3= (2a + b) x h

(a + b) x 3

h3= 0.734 m


4.55

Pp= Kph

Above RL + 395.639 , Pp= 5.40 h

Below RL + 395.639 , Pp= 6.30 h

PP at 0.90 m = 4.55 t/m2

PP at 2.70 m = 15.89 t/m2

Fp= 18.40 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.734 m

T0 =

= 15.447 t/m



P0=

Above RL + 395.639 , P0= 0.90 h

Below RL + 395.639 , P0= 1.05 h

Po at 0.90 m = 0.76 t/m2

Po at 2.70 m = 2.65 t/m2

F0= 3.07 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.734 m

T0 =

= 4.62 t/m



W (b - B/3) + F0h2

h1

1.80

h1

2.65

sh (1 - sin)

1.77

1.80

1.80

15.89

W (b - B/3) + Fph2- Fah3


6/15


Uplift = 1.455 x 1.8 x 13 x 1 = 34 t



= 106 t





13 x PI x 1.2 ^2/4 x 1 = 121 t


TF0 60.04

39.86 h2 W h = 0.90 m

A

b

0.90 U


M @ A = 0 :

L.A. = [W- U]b+F0h2-T h

W-U

= (( 120.543 - 34.05 ) x 0.9 + 39.86 x 0.73 - 57.06 x 0.9 ) / ( 120.54 - 34.05 )

= 0.644 m

e = b/2 - L.A = 1.8 / 2 - 0.64 = 0.256 m

B/6 = 0.300

e < B/6 No Tension

p = P/A( 1 6e/B)

pmax = ( 120.54 - 34.05 ) / 23.4 x ( 1 + 6 x 0.26 / 1.8 ) = 6.85 t/m2

pmin = ( 120.54 - 34.05 ) / 23.4 x ( 1 - 6 x 0.26 / 1.8 ) = 0.55 t/m2

3 Check for sliding


= 0.143


7/15




Pipe thickness 8 mm



2













Coeff. of active earth pressure (Ka) = (1-sinF)/(1+ sinF) 0.333Coeff. of passive earth pressure (Kp) = (1+sinF)/(1-sinF) 3.000

+ 399.003 + 399.003

+ 398.103

+ 397.836 2.70 + 397.836

Fa Fp

1.53

h2



WATER PRESSURE

DIAGRAM ON D/s

1.53 1.53





Thrust (T) = 2 P A Sin ( / 2) = 25.04 t


a

B = 1.80

H = 1.80

0.90


Soil

h1h3

T0 PIPE


8/15

T0 = W(b - B/3)/h1 = 2.119 t/m

L = T / To = 12.00 m



0.51

Pa= Kah

Above RL + 397.836 , Pa= 0.60 h

Below RL + 397.836 , Pa= 0.70 h

Pa at 0.90 m = 0.51 t/m2

Pa at 2.70 m = 1.77 t/m2

Fa= 2.06 t

h3= (2a + b) x h

(a + b) x 3

h3= 0.735 m


4.6197

Pp= Kph

Above RL + 397.836 , Pp= 5.40 h

Below RL + 397.836 , Pp= 6.30 h

PP at 0.90 m = 4.62 t/m2

PP at 2.70 m = 15.96 t/m2

Fp= 18.52 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.735 m

T0 =

= 15.559 t/m



P0=

Above RL + 397.836 , P0= 0.90 h

Below RL + 397.836 , P0= 1.05 h

Po at 0.90 m = 0.77 t/m2

Po at 2.70 m = 2.66 t/m2

F0= 3.09 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.735 m

T0 =

= 4.64 t/m



2.66

sh (1 - sin)

1.77

1.80

1.80

15.96

W (b - B/3) + Fph2- Fah3

W (b - B/3) + F0h2

h1

1.80

h1


9/15


Uplift = 1.533 x 1.8 x 6 x 1 = 17 t



= 49 t





6 x PI x 1.2 ^2/4 x 1 = 56 t


TF0 27.84

18.52 h2 W h = 0.90 m

A

b

0.90 U


M @ A = 0 :

L.A. = [W- U]b+F0h2-T h

W-U

= (( 55.635 - 16.56 ) x 0.9 + 18.52 x 0.73 - 25.04 x 0.9 ) / ( 55.64 - 16.56 )

= 0.671 m

e = b/2 - L.A = 1.8 / 2 - 0.67 = 0.229 m

B/6 = 0.300

e < B/6 No Tension

p = P/A( 1 6e/B)

pmax = ( 55.64 - 16.56 ) / 10.8 x ( 1 + 6 x 0.23 / 1.8 ) = 6.37 t/m2

pmin = ( 55.64 - 16.56 ) / 10.8 x ( 1 - 6 x 0.23 / 1.8 ) = 0.86 t/m2

3 Check for sliding


= 0.117


10/15




Pipe thickness 8 mm



2














+ 399.914 + 399.914

+ 399.014

+ 398.637 2.70 + 398.637

Fa Fp

1.42

h2



WATER PRESSURE

DIAGRAM ON D/s

1.42 1.42





Thrust (T) = 2 P A Sin ( / 2) = 14.69 t

H = 1.80

0.90


Soil

h1

B = 1.80


a

h3

T0 PIPE


11/15

T0 = W(b - B/3)/h1 = 2.119 t/m

L = T / To = 7.00 m



0.50

Pa= Kah

Above RL + 398.637 , Pa= 0.60 h

Below RL + 398.637 , Pa= 0.70 h

Pa at 0.90 m = 0.50 t/m2

Pa at 2.70 m = 1.76 t/m2

Fa= 2.04 t

h3= (2a + b) x h

(a + b) x 3

h3= 0.733 m


4.5207

Pp= Kph

Above RL + 398.637 , Pp= 5.40 h

Below RL + 398.637 , Pp= 6.30 h

PP at 0.90 m = 4.52 t/m2

PP at 2.70 m = 15.86 t/m2

Fp= 18.34 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.733 m

T0 =

= 15.400 t/m



P0=

Above RL + 398.637 , P0= 0.90 h

Below RL + 398.637 , P0= 1.05 h

Po at 0.90 m = 0.75 t/m2

Po at 2.70 m = 2.64 t/m2

F0= 3.06 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.733 m

T0

=

= 4.61 t/m



W (b - B/3) + F0

h2

h1

1.80

h1

2.64

sh (1 - sin)

1.76

1.80

1.80

15.86

W (b - B/3) + Fph2- Fah3


12/15


Uplift = 1.423 x 1.8 x 4 x 1 = 10 t



= 33 t





4 x PI x 1.2 ^2/4 x 1 = 37 t


TF0 18.44

12.23 h2 W h = 0.90 m

A

b

0.90 U


M @ A = 0 :

L.A. = [W- U]b+F0h2-T h

W-U

= (( 37.09 - 10.25 ) x 0.9 + 12.23 x 0.73 - 14.69 x 0.9 ) / ( 37.09 - 10.25 )

= 0.741 m

e = b/2 - L.A = 1.8 / 2 - 0.74 = 0.159 m

B/6 = 0.300

e < B/6 No Tension

p = P/A( 1 6e/B)

pmax = ( 37.09 - 10.25 ) / 7.2 x ( 1 + 6 x 0.16 / 1.8 ) = 5.70 t/m2

pmin = ( 37.09 - 10.25 ) / 7.2 x ( 1 - 6 x 0.16 / 1.8 ) = 1.76 t/m2

3 Check for sliding


= 0.066


13/15




Pipe thickness 8 mm



2














+ 411.253 + 411.253

+ 410.353

2.70

+ 409.721 + 409.721

Fa Fp

1.17

h2



WATER PRESSURE

DIAGRAM ON D/s

1.17 1.17





Thrust (T) = 2 P A Sin ( / 2) = 31.56 t


a

B = 1.80

H = 1.80

0.90


Soil

h1h3

T0 PIPE


14/15

T0 = W(b - B/3)/h1 = 2.119 t/m

L = T / To = 15.00 m



0.48

Pa= Kah

Above RL + 409.721 , Pa= 0.60 h

Below RL + 409.721 , Pa= 0.70 h

Pa at 0.90 m = 0.48 t/m2

Pa at 2.70 m = 1.74 t/m2

Fa= 1.99 t

h3= (2a + b) x h

(a + b) x 3

h3= 0.729 m


4.2912

Pp= Kph

Above RL + 409.721 , Pp= 5.40 h

Below RL + 409.721 , Pp= 6.30 h

PP at 0.90 m = 4.29 t/m2

PP at 2.70 m = 15.63 t/m2

Fp= 17.93 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.729 m

T0 =

= 15.033 t/m



P0=

Above RL + 409.721 , P0= 0.90 h

Below RL + 409.721 , P0= 1.05 h

Po at 0.90 m = 0.72 t/m2

Po at 2.70 m = 2.61 t/m2

F0= 2.99 t

h2= (2a + b) x h

(a + b) x 3

h2= 0.729 m

T0 =

= 4.54 t/m



2.61

sh (1 - sin)

1.74

1.80

1.80

15.63

W (b - B/3) + Fph2- Fah3

W (b - B/3) + F0h2h1

1.80

h1


15/15


Uplift = 1.168 x 1.8 x 7 x 1 = 15 t



= 57 t





7 x PI x 1.2 ^2/4 x 1 = 65 t


TF0 31.79

20.92 h2 W h = 0.90 m

A

b

0.90 U


M @ A = 0 :

L.A. = [W- U]b+F0h2-T h

W-U

= (( 64.908 - 14.72 ) x 0.9 + 20.92 x 0.73 - 31.56 x 0.9 ) / ( 64.91 - 14.72 )

= 0.638 m

e = b/2 - L.A = 1.8 / 2 - 0.64 = 0.262 m

B/6 = 0.300

e < B/6 No Tension

p = P/A( 1 6e/B)

pmax = ( 64.91 - 14.72 ) / 12.6 x ( 1 + 6 x 0.26 / 1.8 ) = 7.46 t/m2

pmin = ( 64.91 - 14.72 ) / 12.6 x ( 1 - 6 x 0.26 / 1.8 ) = 0.51 t/m2

3 Check for sliding


= 0.164

Thrust Block Design JNT450

Documents

Transcript of Thrust Block Design JNT450