A counterfort retaining wall is a cantilever wall with counterforts, or buttresses, attached to the inside face of the wall to further resist lateral thrust. Some common materials used for retaining walls are treated lumber, concrete block systems, poured concrete, stone, and brick.

Where do we use Counterfort retaining wall?

The counterfort retaining wall is a retaining wall with counterforts attached to the inside face of the wall to resist further lateral thrust, and materials used for retaining walls are treated lumber, concrete block systems, stone, brick, and poured concrete.

What are the main components of the Counterfort retaining wall?

Counterfort retaining wall consists of a stem, toe slab and heel slab as in case of cantilever retaining wall. But it also consists of counterforts are regular interval which divides the stem. The stem with combination of counterfort behaves like a tee-beam with varying width.

What is front and back Counterfort retaining wall?

Counterforts are firmly attached to the face slab as well as the base slab. The earth pressure acting on the face slab is transferred to the counterfort which deflects as vertical cantilever. The back of rear counterfort comes under tension and the front face is under compression.

Under what circumstances Counterfort retaining wall is preferred?

Counterfort retaining walls are used for height of backfill more than 6m and for higher earth-pressure magnitudes.

Design of Counterfort Retaining Wall #Part-1

What does Counterfort mean?

: a buttress built against or integral with a wall (as a retaining wall or dam) but on the back or thrust-receiving side.

What are the assumptions of Rankine's theory?

The Rankine's theory assumes that there is no wall friction , the ground and failure surfaces are straight planes, and that the resultant force acts parallel to the backfill slope. In case of retaining structures, the earth retained may be filled up earth or natural soil.

What is a Counterfort wall?

A counterfort retaining wall is a cantilever wall with counterforts, or buttresses, attached to the inside face of the wall to further resist lateral thrust. Some common materials used for retaining walls are treated lumber, concrete block systems, poured concrete, stone, and brick.

What is the need of Counterfort retaining wall?

Counterfort Retaining Walls

The counterforts tie the slab and base together, and the purpose of them is to reduce the shear forces and bending moments imposed on the wall by the soil. A secondary effect is to increase the weight of the wall from the added concrete.

What is stem in Counterfort retaining wall?

The stem acts as a continuous slab. Soil pressure acts as the load on the slab. Earth pressure varies linearly over the height. The slab deflects away from the earth face between the counterforts. The bending moment in the stem is maximum at the base and reduces towards top.

What is toe wall in Bridge?

[′tō ‚wȯl] (civil engineering) A low wall constructed at the bottom of an embankment to prevent slippage or spreading of the soil.

What are the functions of retaining wall discuss the component of Counterfort type retaining wall?

Counterfort walls are cantilever walls strengthened with counter forts monolithic with the back of the wall slab and base slab. The counter-forts act as tension stiffeners and connect the wall slab and the base to reduce the bending and shearing stresses.

What is toe wall in building?

: a low retaining wall especially : an embankment wall in a railroad cut.

What is a cantilever wall?

Cantilever walls are walls that do not have any supports and thus lead to an open unobstructed excavation. Cantilever walls laterally restrain the retained side of the excavation by the passive resistance provided below the excavation depth.

What is the purpose of diaphragm wall?

Diaphragm walls are underground structural elements commonly used as retention systems and permanent foundation walls. They can also be used as groundwater barriers.

Why shear key is provided?

Shear key is provided to increase the resistance to sliding. The shear key is generally an extension of the vertical stem and extends below the bottom of the base. The main purpose of the installation of shear keys is to increase the extra passive resistance developed by the height of shear keys.

What is the structural action between cantilever and Counterfort retaining wall?

In cantilever retaining wall the pressure and other forces are withstand by the stem of the retaining wall and base slab. In counterfort retaining wall is provided the height of retaining wall is more than 6m. the walls also provided perpendicular to stem wall. The counterfort act as support to stem and heel slab.

What are the forces acting on retaining wall?

The lateral Earth pressure due to earth pressure is the major force acting on the retaining wall . This pressure act at H/3 above the baseof wall.

What is surcharge in retaining wall?

Surcharge: The vertical load imposed on retained soil that may impose a lateral force in addition to lateral earth pressure of retained soil. For example: Sloping retained soil; structure footings supported by the retained soil; adjacent vehicle loads supported by retained soil.

What are Counterfort drains?

Counterfort drains, also known as buttress or trench drains, provide a method for improving slope stability through controlling groundwater pressures by subsurface drainage. They typically comprise trenches up to 6m depth, with a perforated pipe at the base, backfilled with suitable free-draining material.

How does a cantilever retaining wall work?

Cantilever retaining walls

Cantilever walls are built using reinforced concrete, with an L-shaped, or inverted T-shaped, foundation. The vertical stress behind the wall is transferred onto the foundation, preventing toppling due to lateral earth pressure from the same soil mass.

What is Counterfort retaining wall the toe can be designed as a cantilever if?

The toe slab of counterfort type retaining wall is designed as cantilever, which subject to downward and upward forces due to self-weight and earth pressure, respectively in the condition when no front counterforts are provided.

What is Rankine's formula?

Answers. It is an empirical formula used for the calculation of ultimate load both for short and long columns. Rankin's formula is also known as Rankin Gordon Formula. It gives the ultimate load that column can bear before failure. If column is short, calculated load will be known as crushing load.

What is KA and KP in soil mechanics?

Ka = Active Earth Pressure 3. Kp = Passive Earth Pressure (Passive is more like a resistance) Earth Pressure At Rest At rest earth pressure occur when there is no wall rotation such as in a braced wall. (

What is Rankine's earth pressure?

To analyse the pressure relation between retaining wall and soil mass, the most commonly used theory is Rankine's Earth Pressure Theory. Three conditions are analysed - Wall at rest, Active Earth Pressure and Passive Earth Pressure. Rankine's theory assumes the wall to be smooth and soil cohesionless.