Retaining wall

Retaining wall:
Retaining walls are structure used to retain soil, rock or other materials in a vertical
condition.
Hence they provide a lateral support to vertical slopes of soil that would otherwise collapse
into a more natural shape.
Most common materials used for retaining walls are:
- Wood sheets;
- Steel and plastic interlocking sheets;
- Reinforced concrete sheets;
- Precast concrete elements (crib walls and block walls);
- Closely spaced in-situ soil-cement piles;
-- Wire-mesh boxes (gabions);
- Anchors into the soil or rock mass (soil nailing).

EARTH RETAINING STRUCTURE
Earth retaining structure can be classified to 2 types:
A) Externally Stabilized Systems
i) In- Situ Walls
ii) Gravity Walls

B) Internally Stabilized Systems
i) Reinforced Soils
ii) In-Site Reinforcement

FUNCTION

To retain the soil at a slope that is greater than it would
naturally assume, usually at a vertical or near vertical
position.

DESIGN
The designed retaining wall must be able to
ensure the following :
 Overturning doesn’t occur
 Sliding doesn’t occur
 The soil on which the wall rests mustn’t be
overloaded
 The material used in construction are not
overstressed.

DESIGN CONSIDERATION
In order to calculate the pressure exerted at
any point on the wall, the following must be
taken in account:
 height of water table
 nature & type of soil
 subsoil water movements
 type of wall
 material used in the construction of wall

The effect of 2 forms of earth pressure need to
be considered during the process of designing
the retaining wall that is:
a) Active Earth Pressure
“ It is the pressure that at all times are tending
to move or overturn the retaining wall”
a) Passive Earth Pressure
“It is reactionary pressures that will react in
the form of a resistance to movement of the
wall.

ACTIVE EARTH PRESSURE
It is composed of the earth wedge being retained
together with any hydrostatic pressure caused by
the presence of groundwater.
This pressure can be reduced by:
i) The use of subsoil drainage behind the wall
ii) Inserting drainage openings called weep holes
through the thickness of the stem to enable the
water to drain away.

PASSIVE EARTH PRESSURE
• This pressure build up in front of the toe to
resist the movement of the wall if it tries to
move forward.
• This pressure can be increased by enlarging the
depth of the toe or by forming a rib on the
underside of the base.

GRAVITY WALL
There are many types of gravity wall such as
the followings:
a) Massive Gravity Wall
b) Crib Wall
c) Cantilever Gravity Wall

cement mortar

plain concrete or
stone masonry
cobbles

They rely on their self weight to
support the backfill
12

 It’s construction only need simple materials
and moderately skilled labor
 But the required volume of material is very
large because there’s steel reinforcement is
used.
 Even though it need moderately skilled
labor but the construction process is very
labor extensive.

MASSIVE GRAVITY WALL
 Often made of mortared stones, masonry or
reinforced concrete
 It resist the lateral forces from the backfill
by virtue of their large mass
 These walls are very thick, so the flexural
stresses are minimal and no reinforcement
is needed.

CRIB WALL
 Another type of gravity retaining structure
 It consists of precast concrete members
linked together to form a crib
The zone between the member is filled with
compacted soil

CANTILEVER GRAVITY WALL
STEM
8 IN WIDE
CONCRETE
BLOCKS

SOIL
REINFORCING
STEEL

12 IN. WIDE
CONCRETE
BLOCK
TOE

Large Flexural Stresses
At Base Of Stem
REINFORCED
CONCRETE FOOTING
HEEL

CANTILEVER GRAVITY WALL


It is a refinement of the massive gravity wall concept

 These wall have much thinner stem and utilize the weight of the
backfill soil to provide most of the resistance to sliding and overturning
 These walls require much less construction material because the cross
section of this wall is much smaller.
 It have a large flexural stresses which requires the use of reinforced concrete
or reinforced masonry
 It must be carefully constructed & requires skillful labor
 less expensive than mass gravity walls
 most common type of earth retaining structure.

Reinforced;
smaller section
than gravity
walls

They act like vertical
cantilever, fixed to the ground
19

IN-SITU WALL
 Different from gravity walls
 There are many types of In-Situ wall such
as the followings:
a) Sheet Pile Walls
b) Soldier Pile Walls
c) Slurry Pile Walls

SHEET PILE WALLS


Sheet piles are tine, wide steel piles

 Driven to the ground using pile hammer
 Series of sheet piles in a row form a sheet pile wall
 It’s usually necessary to provide lateral support at 1 or more levels above
the ground that can be done using 2 ways that is internal braces or tieback
anchor.
 Tieback Anchors are tension members drilled into the ground behind the
wall
 The most common type is a grouted anchor with a steel tendon.

GROUTED TIEBACK
ANCHOR

WALER

SHEET PILE WALL
SOIL

• Wall With Tieback Anchors

SOLDIER PILE WALLS


Consist of a vertical wide flange steel members with horizontal timber
lagging.
 Often used as temporary retaining structures for construction
excavation

SLURRY WALLS
 It’s a cast-in-place concrete walls built using
betonies slurry
 The contractor digs a trench along the proposed
wall alignment and keeps it open using the slurry
 The reinforcing steel is inserted and the concrete
is placed using pumps.
As the concrete fills the trench, slurry exits at the
ground surface.

Basha

Retaining Walls - Applications

Metros and Subways

Road
Train

31

Basha


highway

32

Basha


High-rise building

basement wall

33

Advances in retaining wall
Reinforced Retaining Walls
• Sometimes the complexity or wall height required for certain
installations require retaining walls that are reinforced by either
geofabric material or, in really tough cases, concrete filled doubleskin
layers of blocks

Geosynthetic Reinforced Soil
Segmental Retaining Walls
• Geosynthetic reinforced soil segmental retaining
walls utilize reinforcing sheets of geogrid or
suitable woven geotextile which are attached to the
fascia and are embedded in a body of engineered
fill.
• The integrated nature of the fascia and the abutting
large body of reinforced soil thereby supports the
applied earth forces. In this case the 'gravity'
component of the retaining wall is provided by the
reinforced soil mass acting as a monolithic unit.

Retaining wall

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Retaining wall

Similar to Retaining wall (20)

More from Hamzah Meraj, Faculty of Architecture, Jamia Millia Islamia, New delhi

More from Hamzah Meraj, Faculty of Architecture, Jamia Millia Islamia, New delhi (20)

Recently uploaded

Recently uploaded (20)

Retaining wall