Retaining walls

Retaining walls are used to retain earth (or other material) in a vertical position at locations where an abrupt change in ground level occurs.
The walls therefore prevents the retained earth from assuming its natural angle of repose.

1. RETAINING
WALLS
MENOUFIA UNIVERSITY
FACULTY OF ENGINEERING
CIVIL ENGINEERING DEPARTMENT
AHMED ZAID SAIF
facebook.com/ahmedzaidsaif

2. introduction
Retaining walls are used to retain earth (or
other material) in a vertical position at
locations where an abrupt change in ground
level occurs.
The walls therefore prevents the retained earth
from assuming its natural angle of repose.

3. Earth Stone retaining wall

4. Stone retaining wall

5. Stone retaining wall

6. Brick retaining wall

12. Retaining wall failure at the Shin-Kang Dam

13. Failure of retaining wall (dam) due to water pressure..

14. Retaining wall failure in Austria on
30th October 2012

15. applications of retaining wall
A Retaining Wall Maintaining The Difference Between The
Elevations Of The Ground Surface.

16. applications of retaining wall
Retaining Wall Of A Basement

17. applications of retaining wall
A Tunnel Portal

18. applications of retaining wall
MAINTAINING THE LEVEL BETWEEN A
HIGHWAY AND A CONTOUR LAND

19. Retaining wall is
a structure used
for maintaining
the ground
surfaces at
different
elevations on
either side of it.
definition

20. All permanent walls and components shall be designed
for a minimum service life of 75 years.
Corrosion protection is required for all permanent
and temporary walls in aggressive environments.
Retaining walls are usually built to hold back soil
mass.
They are also provided to maintain the grounds at two
different levels.

21. parts
TOE
HEEL
KEY
BACKFILL
FRONT

22. 1. Gravity Retaining Walls
2. Semi-Gravity Retaining Walls
3. Cantilever Retaining Walls
4. Counter fort Retaining Walls
5. Anchored Retaining Walls
6.Buttress Retaining Wall
7.Sheet Piling Retaining Walls
8. Segmental Retaining Walls
9. Wooden Retaining Walls
10. Gabion Retaining Walls
types of retaining walls

23. The “gravity wall” provides stability
by virtue of its own weight , and
therefore, is rather massive in size.
It is usually built in stone masonry, and
occasionally in plain concrete
graVity walls

24. The thickness of wall is also
governed by need to eliminate or
limit the resulting tensile stress to its
permissible limit .
Plain concrete gravity walls are not
used for heights exceeding about 3m,
for obvious economic reasons.

26. gravity wall

28. seMi-graVity walls
Semi-gravity walls
resist external forces
by the combined
action of self weight,
weight of soil above
footing and the
flexural resistance of
the wall
components.

29. concrete cantilever wall is an
example and consists of a
reinforced concrete stem and
a base footing.
These walls are non-
proprietary.
seMi-graVity walls

30. seMi-graVity walls

31. cantileVer wall
The “Cantilever wall ” is
the most common type of
retaining structure and is
generally economical for
heights up to about 8m.
The structure consists of
vertical stem , and a base
slab, made up of two
distinct regions, viz., a
heel slab and a toe slab

32. cantileVer wall

33. cantileVer wall

34. cantileVer wall

35. cantileVer wall

36. “Stem” acts as a vertical
cantilever under the lateral
earth pressure
“Heel slab” acts as a horizontal
cantilever under the action of
weight of the retained earth
(minus soil pressure acting
upwards from below)
“Toe slab ” acts as a cantilever
under the action of resulting
soil pressure acting upward.

37. It resists the horizontal
earth pressure as well as
other vertical pressure
by way of bending of
various components
acting as cantilevers.
May be L shaped or T
shaped.

38. counterfort wall
Stem and Heel slab are strengthened by
providing counterforts at some suitable
intervals.
The stability of the wall is maintained
essentially by the weight of the earth on
the heel slab plus the self weight of the
structure.

42. For large heights, in a
cantilever retaining
wall, the bending
moments developed in
the stem, heel slab and
toe slab become very
large and require large
thickness.
The bending moments
can be considerably
reduced by introducing
transverse supports,
called counterforts.

43. Counterfort wall are placed at
regular intervals of about1/3 to ½
of the wall height, interconnecting
the stem with the heel slab.
The counterforts are concealed
within the retained earth on the
rear side of the wall.

44. This wall is economical for
heights above
(approximately) 7m.
The counterforts subdivide the vertical
slab (stem) into rectangular panels and
support them on two sides(suspender-
style), and themselves behave
essentially as vertical cantilever beams
of T-section and varying depth.

45. ancHored retaining walls
These walls are
pinned both top
and bottom
using cables,
or other stays,
which are
anchored in the
rock or soil
behind it.

46. ancHored retaining walls

47. ancHored retaining walls

48. ancHored retaining walls

49. ancHored retaining walls

50. buttress wall
It is similar to
counterfort wall, except
that the transverse stem
supports, Called
buttress, are located in
the front side,
interconnecting the
stem with the toe
slab(and not with heel
slab, as with
counterforts)

51. Although the buttresses are
structurally more efficient (and
more economical) counterforts,
the counterfort wall is generally
preferred to the buttress wall as
it provides free usable space
(and better aesthetics)in front of
the wall.
buttress wall

52. buttress wall

53. buttress wall

54. sHeet piling retaining walls
Sheet pile retaining walls
are usually used in soft
soils and tight spaces.
Sheet pile walls are made
out of steel, vinyl or wood
planks which are driven
into the ground.

55. sHeet piling retaining walls
Taller sheet pile walls will need
a tie-backanchor, or "dead-man"
placed in the soil a distance
behind the face of the wall, that
is tied to the wall, usually by a
cable or a rod.Anchorsare then
placed behind the potential
failure plane in the soil.

56. sHeet piling retaining walls

57. sHeet piling retaining walls

58. sHeet piling retaining walls

59. sHeet piling retaining walls

60. sHeet piling retaining walls

61. segMental retaining walls
segmental retaining
wallsutilize reinforcing
sheets of geogridor suitable
woven geotextile which are
attached to the fascia and are
embedded in a body of
engineered fill.

62. segMental retaining walls

63. segMental retaining walls

64. segMental retaining walls

65. wooden retaining walls
it’s the simple construction and low
costs that make timber retaining
walls the most common choice for
do-it-yourself home improvement.
This kind of wall is also an
affordable way your landscape
contractor can control short slopes
that may erode or prove unstable
over time

66. wooden retaining walls

67. wooden retaining walls

68. wooden retaining walls

69. gabion retaining walls
Costs: Wire mesh gabions are
less expensive than most other
construction materials.
Many gabion structures may be
built without any mechanical
equipment.
Upon completion, a gabion
structure will take its full load
immediately

70. gabion retaining walls

71. gabion retaining walls

72. gabion retaining walls

73. selection of wall type
paraMeter
The Type Of Retaining Wall
The Material To Be Retained
The Constructability Of The Wall System
Design Life, Durability And Long Term
Maintenance
The Footprint Of The Wall
Aesthetics
Adherence To Retaining Structures Code

74. tHe type of retaining wall
Retaining walls can be broadly divided
into four main categories —namely,
gravity walls, cantilever walls, anchored
walls, and reinforced soil or nailed
walls.
Each type of retaining wall has its own
particular characteristics, which make it
more suitable for certain applications
than others.

75. tHe Material to be retained
Important questions to ask upfront include:
Will the wall be retaining a cut face or fill
material?
If it is fill material, will it be controlled fill?
If it is a cut face, what type of ground is it?
Generally, building a wall to retain fill
material allows for a wider choice of wells
than a wall designed to retain cut faces.

76. tHe constructability of tHe
wall systeM
This includes considerations such as:
The wall environment (for example whether it is
adjacent to water, the soil chemistry, salinity, etc)
The size of the footprint available for the wall
The required height and length of the wall
The slope of the ground above the wall
The slope of the ground at the bottom of the wall
Any surcharge loads applied above the wall

77. design life, durability and
long terM Maintenance
The structure must be durable and meet
the design life requirements stipulated in
the relevant construction codes.
Long-term maintenance requirements
must be taken into consideration and
factored into the cost.

78. aestHetics
This has become an increasingly important
consideration in the selection, design and
construction of retaining walls.
Modern walls can be planted out and/or coloured
with long-lasting colouredsealants to enhance the
aesthetic aspect.
Concrete sleeper walls have the advantage over
timber walls as they can be constructed with a
wood grain finish, colouredwith sealers, and they
do not rot.

79. adHerence to retaining
structures code
Retaining Structures
Code, and any
manufactured/fabricated
products must also
comply with their
respective codes

80. factors wHicH designer
need to take account
Nature and characteristics of the subsoil's
Height of water table –the presence of water
can create hydrostatic pressure, affect bearing
capacity of the subsoil together with its shear
strength, reduce the frictional resistance
between the underside of the foundation
Type of wall
Materials to be used in the construction

81. lateral eartH pressures
Earth pressure is
the pressure
exerted by the
retaining
material on the
retaining wall.
This pressure
tends to deflect
the wall outward.
P
a
GL
Variation of Earth pressure

82. lateral eartH pressures

83. pressure at rest
When the soil behind the wall is
prevented from lateral movement
(towards or away from soil) of wall, the
pressure is known as earth pressure at
rest.
This is the case when wall has a
considerable rigidity.
Basement walls generally fall in this
category.

84. pressure at rest

85. actiVe eartH pressure
If a retaining wall is allowed to
move away from the soil
accompanied by a lateral soil
expansion, the earth pressure
decreases with the increasing
expansion.

86. actiVe eartH pressure

87. A shear failure of the soil is
resulted with any further
expansion and a sliding
wedge tends to move forward
and downward. The earth
pressure associated with this
state of failure is the
minimum pressure and is
known as active earth
pressure.

88. passiVe eartH pressure
If a retaining wall is allowed to
move towards the soil
accompanied by a lateral soil
compression, the earth
pressure increase with the
increasing compression in the
soil.

89. passiVe eartH pressure

90. THANKS!
F O R L I S T E N I N G T O M E T O D A Y