canal fall types,design steps of vertical drop fall, design of sheet pile, cistern, impervious floor, bligh creep theory, khosla theory, cutoff drop structure, wing walls

1. 3/18/2014 1
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

2. 3/18/2014
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET
2

3. u/s pile depth
u/s floor length
Top width of fall
Bottom width of fall
Height of fall
Length of cistern
Depth of cistern
Thickness of floor
d/s floor length
Depth of intermediate and d/s pile
3/18/2014 3
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

4. 1.5 M
0.85 M
D = 2.25 m
5.5. m
0.3 m
3/18/2014 4
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET
101.5
101.2
103.77

5. 3/18/2014 5
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

6. Impervious floor : (Bligh
creep theory)
Total creep length –
(L) = CHs
Where Maximum seepage head = Hs
= crest level – d/s bed level
L = 2d1 + l + 2d2
3/18/2014 6
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

7. L = 2d1 + l + 2d2
L = total creep length,
d1 = depth of u/s cutoff , d2 = depth
of d/s cutoff , &
l or b = length of impervious floor
l =b
d1
d2
lu ld1.5 m
3/18/2014 7
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

8. Minimum length of d/s floor
required,
Thus the length of u/s floor
3/18/2014 8
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

9. `
L =
L = 13.7 (creep length)
D1
3/18/2014 9
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

10. Impervious floor length l or b from
equation L = 2d1 + l + 2d2
L = 2(0.5) + l + 2(0.75) = 13.7
l or b = 11.20
3/18/2014 10
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

11. Minimum length of d/s floor
required,
3/18/2014 11
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

12. l =b = 11.2 mD1 = 0.5
D2
=
0.75
2.7 1.5 m
7. 0 m
0.6
m 0.6
m
Floor length and cutoff
3/18/2014 12
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

13. Thickness of floor as per Bligh
3/18/2014 13
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

14. t = residual head at any point / G – 1
Where Residual Head = hr
hr = depth of cistern
+
creep length
upto the point





 
lengthtotalcreep
bedlevelRLofcrest
3/18/2014 14
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

15. Thickness of floor as per Bligh
103.77
3/18/2014 15
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

16. Thickness of floor as per Bligh
(a) Residual head (static head) at
the d/s toe of the crest wall
3/18/2014 16
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

17. Thickness of floor as per Bligh
103.77
3/18/2014 17
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

18. Thickness of floor as per Bligh
(b) Residual head at 3 m from the toe
of the crest wall :
Hr = 0.3 + (4 + 0.75 + 0.75)
= 1.21
hr = depth of cistern
+
creep length
upto the point




 
lengthtotalcreep
bedlevelRLofcrest





 
70.13
5.10177.103
3/18/2014 18
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

19. (c) Residual head at 5 m from the
toe of the crest wall
3/18/2014 19
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

20. Thickness of u/s floor :
The uplift pressure on the u/s floor
will be counter balanced by the
weight of water
and soil. Therefore, provide a
nominal thickness of 0.30
3/18/2014 20
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

21. u/s wing wall :
It shall be splayed straight at an
angle of 45° from the u/s edge of the
crest and shall be embedded by 1.0
m into the berm.
Top level of u/s wing wall =
= 104.5 + 0.6 (free board) = 105.10
m
3/18/2014 21
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

22. 5. D/s wing walls :
Length of d/s wing walls
with a vertical face measured from
the crest wall
3/18/2014 22
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

23. 3/18/2014 23
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

24. 6". D/s bed pitching :
Pitching is kept at 1 : 10. A curtain
wall (cutoff) shall be provided at
the end of pitching.
3/18/2014 24
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

25. Thickness of floor as per Bligh
103.77
12 M
PITCHING
3/18/2014 25
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

26. 3/18/2014 26
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

27. 3/18/2014 27
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

28. 3/18/2014 28
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET

29. 3/18/2014 29
PREPARED BY V.H.KHOKHANI
ASSISTANT PROFESSOR, DIET