retaining wall preserdistribution

1. SHEET PILES
BY
BOGATHI MADHUSUDARSAN REDDY
ROLL NO:203621006

2. Presentation outline:
•Definition of sheet piles.
•Use of sheet piles.
•Advantages and disadvantages.
•Different types of sheet piles.
•Construction method.
•cantilever sheet pile(granular soil).

3. • Sheet piles are sections of sheet materials with
interlocking edges are driven into the ground to
provide earth retention and excavation support. Sheet
piles are most made of steel but can also be formed of
timber or reinforced concrete.
• Sheet piles are commonly used for retaining walls, land
reclamation, underground structures such as car parks
and basements in marine locations for riverbank
protection, seawalls, cofferdams and so on.
•Definition of sheet
piles:

4. Use of sheet piles:
oRetaining walls.
oBridge abutments.
oTunnels.
oPumping station.
oWater treatment plants.
oBasements.
oUnderground car parks.
oPort facilities.
oLocks and dams.
oWaterfront structures.
oPiled foundations.
o Coffer dams.
o Groundwater diversion.
o Barrier for ground water
treatment systems.
o Containment walls.
o Flood protection.
o Coastal protection.
o Slope stabilization.
o Landfill.
o Excavations and trenches.
o Weir

5. Advantages and disadvantages.
Advantages:
1. Provides high resistance to driving stresses.
2. Light weight.
3. Can be reused in several projects.
4. Long service life under water and above the ground
with the modest protection.
5. Easy to adapt the pile length by either welding or
bolting.

6. Advantages and disadvantages.
Disadvantages:
1. Sections can rarely be used as part of the permanent
structure.
2. Installation of sheet piles is difficult in soils with
boulders or cobbles. In such cases, the desired wall
depths may not be reached.
3. Excavation shapes are dictated by the sheet pile section
and interlocking elements.

7. Advantages and disadvantages.
Disadvantages:
4. Sheet pile driving may cause neighborhood
disturbance.
5. Settlements in adjacent properties may take place due
to installation vibrations.

8.  Timber sheet piles:
Timber sheet piles are generally used for
short spans in temporary structure, and to
resist light lateral loads. They are typically
connected by tongue and groove joints.
Reinforced concrete sheet
piles:
Reinforced concrete sheet piles are formed
using precast concrete members, usually
connected by tongue groove joints.
Different types of sheet piles:

9. They are commonly used in permanent river embankments,
canals and other marine structures.
Steel sheet piles:
 Steel is the most common form of sheet piles; as it has good
resistance to high driving stresses, excellent water-tightness, and can
be increased in length either by welding or bolting. They are
connected by interlocking.
They are four different types of steel
sheet piles
• Normal sections.
• Straight web sections.
• Box sections.
• Composite sections.

10. Construction method
Sheet piles may be divided into two basic categories.
1. Cantilever sheet pile.
2. Anchored sheet pile.
Construction methods generally can be divided into two
categories.
a) Backfilled structure.
b) Dredged structure.

11. Sequence for backfilled structure:
Step 1:Dredged the situ soil in front and back of the proposed structure.
Step 2:Drive the sheet piles.
Step 3:Backfill up to the level of the anchor and place the anchor
system.
Step 4:Backfill up to the top of the wall.
Construction method

12. Sequence for dredged structure:
Step 1:Drive the sheet piles.
Step 2:Backfill up to the level of the anchor and place the anchor
system.
Step 3:Backfill up to the top of the wall.
Step 4:Dredged the front side of the wall.
Construction method

13. cantilever sheet pile(granular soil):
pressure calculations

14. cantilever sheet pile(granular
soil): pressure calculations
This was the
deflection
pattern of sheet
pile
A
B
D
H
a
D
Net pressure diagram Converted net diagram
Cantilever sheet pile in granular soil
z
Pa
a
y
Y-z
c1
c2
A
D
Active pressure
Passive pressure
Pp2b
Pp1b
𝑌

15. cantilever sheet pile(granular
soil): pressure calculations
 The converted pressure diagram is used for easy calculations.
 Active pressure occurs when the wall moves away from the backfill
and dredged soils.
 Passive pressure occurs when the wall moves towards the backfill and
dredged soils.
 Where ‫=ץ‬unit weight of soil.
Pa=ka H ‫ץ‬ it acts at a height of
2𝐻
3
from the top.

16. cantilever sheet pile(granular
soil): pressure calculations
At c1 point: at c1 point the active pressure and passive pressure is
equal form the converted net diagram.
ka ‫ץ‬ (H+a)=kp‫ץ‬ a
a=
kp‫ץ‬ a
(kp−ka)‫ץ‬
a=
P𝐴
(kp−ka)‫ץ‬
(1)

17. cantilever sheet pile(granular
soil): pressure calculations
Pp1b=ka ‫ץ‬ (H+D)-kp‫ץ‬ D
Pp2b=(kp- ka)‫ץ‬ y
Sum of horizontal forces is 𝛴𝐹𝐻=Pa+1/2*(Pp1b+ Pp2b)*Z - 1/2* Pp2b*Y =0
Z=
Pp2b∗Y−2Pa
Pp1b+ Pp2b
(2)
Moment at base B is
𝛴MB= Pa(Y+ 𝑌)+1/2*(Pp1b+ Pp2b)*Z*Z/3 – 1/2 * Pp2b*Y*Y/3=0

18. cantilever sheet pile(granular
soil): pressure calculations
By solving above equation we get
6Pa(Y+ 𝑌)+(Pp1b+ Pp2b)*Z2 – Pp2b*Y2 = 0 (3)
In equation 3 we get “Y”.
Determine D = Y+a (4)
 “D” value was increased by 20% to 40% by the reason of factor of
safety.

19. Pressure variations in different
soils and different sheet piles
Pressure variation of
cantilever sheet pile in
cohesive soils.
Pressure variation of
anchored sheet pile in
cohesionless soil.
Pressure variation of
anchored sheet pile in
cohesive soil.

20. Thank you
Reference:
Nptelhrd videos, Mod-01
Lec-26, Lec-27, Lec-28.
Google pictures.