What is Difference between Breast Wall and Retaining Wall?

A retaining wall is built on the top side of the road structure while a breast wall is built on its bottom side.

A retaining wall is used to support an artificial cutting or slope while a breast wall is used to support a natural slope.

Breast walls are built on the hillside and retaining walls are built on the side of the valley along the road.

Breast Wall Vs Retaining Wall:

What is Breast Wall?

Breast walls are built to prevent newly cut slopes on steep hillside embankments from rolling down the hill as a result of bad weather conditions such as sliding and land erosion.

The inclinations and slicing slopes of the hillside might affect the sturdy the road is in steep places.

Travel is prohibited in steep areas where rain can cause minor landslides.

One way to stop these modest slope fragment slips and slides is by using a breast wall.

It is the most cost-effective method of shielding the road shoulder’s edge from the slope’s toe.

Driver safety has therefore improved.

Breast Wall is a wall constructed to stop soil on a naturally occurring slope embankment from sliding down the slope due to harsh weather effects such as land sliding, erosion, etc.

It is near a building or on the downstream side of the street.

Advantages:

The soil on a gradient of a natural barrier is prevented from rolling down as a result of meteorological phenomena such as erosion, excessive rain, and others.
It is suitable for hydraulic structural elements as well.
It helps in some little ways to prevent natural catastrophes like landslides and slope failures.
It is economical.
Construction can be finished using local labour and resources.
In turn, this has improved traffic safety.

Disadvantages:

A breast wall cannot be utilized to support a slope of rock or soil that is geologically unstable or cracked.
It is useless at stopping larger landslides that have a higher surcharge load than can stop tiny landslides.
Too much upkeep is required for the breast wall.
During rainy seasons, you may experience issues with the wall tilting and clogged weep holes.

Uses:

This kind of wall divides a road from a geological hillside’s freshly cut or weathered natural surface.
To prevent mountain landslides, it is particularly considered in regions where the weather and rainfall heavily overlie the slope of the hill.
Additionally, it avoids unanticipated soil slips.
To maintain the look of a natural earthen embankment, it is utilized at the edge of the streets.
It is used along riverbanks to hold the surrounding dirt in place.

How to Design a Breast Wall?

When determining the foundation or approach for the design’s implementation, many aspects of the breast wall design must be taken into consideration as follows:

Due to the magnitude of the earth’s surcharges, the breast wall requires a wider base.

Owing to the increased risk of sliding and toppling, the breast wall shouldn’t be taller than three meters.

A breast wall’s design is determined by several factors such as the excavation’s slope, minimum needed wall height, and strength of the supporting structure.

To reduce the tension caused by saturated soil near the barrier, weep holes must frequently be built up.

It is anticipated that ground pressure or thrusting will exert pressure parallel to the breast wall.

The formula for designing breast walls:

Use the following formula to calculate the total wave force striking the breast wall at a wave peak.

Cp=0.24γHKp

Where KP represents the ordinary pressure coefficient for a non-dimensional variable and Cp denotes the overall wave pressure in kPa.

h represents the actual wave height, whereas “M” is the surge amplitude.

What is a Retaining wall?

To prevent dirt from collapsing onto a road, a retaining wall is built on the upstream side of the road formation.

Retaining types vary frequently according to the height of the retaining wall.

A retaining wall is a wall built of rubble, brick, or RCC to support that resists the pressure of the ground, backfilling, or landslides as needed.

It is often built with a consistent slope on one face, a vertical side on the other, and a bottom thickness that is appropriate for the planned width.

Self-weight of the structure, earth pressure at the rear, any superimposed loads, angle of repose of the soil, soil condition, etc must be taken into account while constructing it.

Advantages:

By installing a retaining wall, you may secure your building.
Retaining walls are made to resist and fight side gravity when your structure is situated in an area with a slope.
Landslides and erosion can be prevented in such a place.
Retaining walls are an efficient way to stop sinkholes from destroying your landscaping.
They are employed to stabilize sloping landscapes that offer flat surfaces on slopes.
A retaining wall can be used to secure the landscaping area, hence over time, maintenance might be reduced.
Retaining walls can improve the aesthetics of the area.

Disadvantages:

Extreme pressure or sharp temperature changes can cause vertical fractures in the poured concrete of some retaining walls.
Brick walls cannot withstand intense soil pressure, which may result in foundation failure or brick breakage.
If your home has a wooden retaining wall, termites might be attracted to it.

Uses:

Soil is supported laterally by retaining walls so that it can be held at various levels on the two sides.
Retaining walls are utilized to produce visually beautiful or useful landscaping elements, make beds out of steep terrain, and aid avoid soil erosion.
They are frequently used when constructing dams.
They could be stand-alone structures or a part of a building or other more substantial construction undertaking.

How to Design a Retaining Wall?

The retaining wall needs to be designed before it can be constructed.

Typically, some information from ground surveys is needed to determine the retained earth and the ground-bearing pressure.

It is possible to excavate test excavations and then provide the data to a structural engineer who will design the wall.

Prepare the surrounding area for the retaining wall by excavating it.
Make sure the ground is firmly in place.
Pour blinding concrete 50 to 100 mm thick over the formation to create a level and flat surface.
Position the beginning bars by fixing them.
They must be positioned correctly.
Fix the supporting timbers from the edge formwork.
The centres will either be 600mm or 800mm depending on the size of the block.
Construct the formwork with concrete.
Verify that the starting bars have not been moved.
Before the concrete sets, it is wise to inspect the starter bars.
First, place the blocks in place.
Put them on top of the starting bars.
Lay the back drainage pipe once the first layer has been finished.
Hydrostatic pressure must not build up, so any water behind the wall needs to be drained.
As you continue, raise the wall to its full height, and backfill it with pristine stone and earth that has been retained.

What is the Difference Between Breast Wall and Retaining Wall?

Breast Wall	Retaining Wall
The piece of the wall that is built above the level of the road is known as the breast wall.	Each of the aspects is taken into consideration by the retaining wall.
Breast walls must be taller than 3 meters.	We did not have any regulations of this nature for retaining walls.
When the soil mass is unstable or involves shaking, no breast wall needs to be created.	A retaining wall is needed to stabilize the unstable soil mass.
The breast wall is used to support a normal slope.	Retaining walls are used to support fake cutting or incline.
The breast wall is used to move the load.	The design of the retaining wall must be suitable to resist the rise in hydrostatic weight and pressure.
The breast wall is the portion of the wall that is constructed above the level of the road.	A retaining wall constructed at a lower elevation than the road level can be seen in a typical design or cross-section of a road.
A maintained sloping surcharge is the sole weight that a breast wall supports.	The retaining wall is designed to resist the weight of the road and the backfill.