A Pier foundation is one of the types of foundation mainly used for bridges, dams, and other large structures. It is also used in the construction of tall buildings.

What is a Pier Foundation?

A pier foundation is made up of large-diameter cylindrical columns that support the superstructure and transfer large superimposed loads to the firm strata below. It was several feet off the ground.

The load of the superstructure is transferred to the underlying soil or rock by the pier footing. It is built by excavating a hole in the ground and filling it with concrete or stone.

It is also known as the "Post foundation" of "Column Foundation". Piers are frequently used in areas where the ground is insufficiently stable to support other traditional foundation types.  Also Read: How Much Does It Cost to Level a House

Types of Pier Foundation

1. Masonry or Concrete Pier:

Brick masonry or concrete foundation piers may be used in excavated pits when a good-bearing stratum exits up to 5 m below ground level.

The pier's size and spacing are determined by the depth of the hard bed, and the nature of the soil is determined by the superimposed load.

The concrete pier is made of concrete and can be precast or cast in place. Precast concrete piers are made in a factory and then driven into the ground at the desired location. Also Read: 

2. Concrete pier or a masonry pier

The concrete pier is constructed of concrete. These precast and cast-in-place piers Precast concrete piers are made in a factory and then driven into the ground at the desired location. Steel wires are commonly used to reinforce precast concrete piers.

There is typically a cross-section of 30 cm to 50 cm and a length of up to 20 m. At the pier's base, a cast steel shoe is provided. Also Read: Types of Foundation Repairs

3. Drilled Caisson Pier

Drilled caisson are cylindrical shape foundations that are constructed from concrete. The intention is to use the concrete or caisson types of foundation to carry higher axial loads applied from the superstructures.

Drilled caissons are constructed up to a deeper depth when compared to the masonry/concrete pier foundations. Further, excavation for these types of foundations could be done with mechanical means.  Also Read: 

Advantages of Pier Foundation

1. Required less skilled labor for most types of foundations
2. Less time-consuming when compared to the other types of foundations.
3. Pires can be used to build structures above the ground and there are many added advantages like running the building services in this gap.
4. There are no vibrations like driven pile foundation

Disadvantages of Drilled Pier Foundations:

1. Installation of drilled piers needs careful supervision and quality control of all the materials used in the construction
2. The method is cumbersome. It needs sufficient storage space for all the materials used in the construction.
3. The advantage of increased bearing capacity due to compaction in granular soil that could be obtained in driven piles is not there in drilled pier construction.
4. Construction of drilled piers at places where there is a heavy current of groundwater flow due to artesian pressure is very difficult.