What Is a Breast Wall? Uses, Types and Construction

1. What is a Breast Wall?

A breast wall is a low stone wall that is constructed on a hillside to support (retain) the natural bank of the earth.

This wall protects a freshly cut or old surface of a natural hill face. It also prevents unstable soils from sliding.

It is mostly considered in areas where rainwater flows down slopes and may cause landslides.

2. Purpose and Uses of Breast Wall

I am from Nepal, a country of hills and mountains. I have seen many landslides along roadsides and riverbanks. Sometimes, instability in a small section of a slope can lead to a much larger landslide. Stabilizing these small slope sections can help reduce the risk of landslides. This is where a breast wall comes in. It helps support the soil and prevent it from sliding down the slope.

Main uses of this wall are:

a. It is used at the sides of the road to retain the face of a natural bank of earth.

b. It is used to retain natural earth at the bank of the rivers.

3. Design Criteria of Breast Wall

The breast wall requires more base width because of surcharge loading exerted by the earth.

The height of the breast wall is not supposed to exceed 3 meters because there is a higher possibility of overturning and sliding.

The design of a breast wall is done based on the height of the wall required, the nature of the backing, and the slope of cutting.

Weep holes should also be provided at regular intervals to reduce the saturated earth pressure at the wall.

The breast wall is designed such that the line of pressure should be normal to the earth’s pressure or thrust.

4. Advantages of Breast Wall

i. It prevents the soil on a natural slope of embankment from sliding down due to the effects of weather like erosion, heavy rainfall, etc.

ii. It can also be used in hydraulic structures.

iii. It plays a great role to control natural disasters like a landslide, slope failures, etc to some extent.

iv. It is economical.

v. Local materials and manpower can be utilized to construct.

vi. It enhances the safety of road users.

5. Disadvantages of Breast Wall

i. It is difficult as well as risky to construct breast walls in hilly areas.

ii. As it is constructed on a steep slope, high chance of overturning and sliding.

iii.  Maintenace and repair work is quite tedious.

6. Types of Breast Wall

There are many types of breast walls based on material or construction. I am explaining 6 types of this wall that i have seen during my journey.

a. Dry Stone Masonry Breast Wall

This wall is made only using stones ( no mortar is used ).

b. Stone Masonry Breast Wall 

This wall is made using stones and cement mortar.

c. Brick Masonry Breast Wall 

This wall is made using bricks and mortar. It is considered more expensive and less stronger than stone masonry breast wall.

d. Plain Cement Concrete Breast Wall

This wall is made using rich grade PCC. ( It is quite expensive than above other wall varieties)

e. Reinforced Cement Concrete Breast Wall

It is the wall made by combined use of PCC and rebars. It is the strongest wall among these 6 types. It is expensive too than others.

f. Gabion Breast Wall

Like a gabion wall, this wall is made using gabion mesh. At first gabion mesh of desired designed is place then mesh is filled with stones.

7. Frequently Asked Questions

a. What is the difference between a breast wall and a retaining wall?

Ans: Breast wall holds natural hill slope but retaining wall holds filled or artificial earth.

b. What is the use of breast wall? 

Ans: It is used at the sides of the road to retain the face of a natural bank of earth.

c. What is the maximum height of breast wall? 

Ans: Maximum height of breast wall shall be 3m.