Precast Concrete Pile: Advantages And Disadvantages [Sizes & Cost]

A pile is a long cylinder made up of strong material usually concrete. It is further pushed into the ground, which gives a steady support to the structures built on top of it.

PRECAST CONCRETE PILE

Pile structures are being used for the places where there is weak layer of soil on the surface. Thus, it cannot support the weight of a heavy building structure. It is being used to support concentrated loads like high-rise structures.

Piles are usually made up of wood, concrete, or steel.

Precast concrete piles are cheap and are also known as displacement piles.

what is PRECAST CONCRETE PILE

It is also the most well-known and widely used foundation method in the world. It is usually the quickest method and also the cheapest besides the use of wooden piles.

Precast concrete piles have high resistance. Their main benefit is high vertical pile load. The allowable capacities for the concrete piles on design build basis is from 125 to over 750 kips per pile.

Precast concrete piles are reinforced concrete piles which comes in different shapes. They could be circular, rectangular, square, or octagonal shape.

There are two types of precast concrete piles which are as follows:

  • Driven Precast concrete piles
  • Bored Precast concrete piles

What is Prestressed Concrete Pile

Prestressed concrete piles play a vital role in the building structures. The primary purpose is to carry the compression loads.

Prestressed concrete pile

These are being used in the foundation of buildings, bridges and marine structures.

The size of the prestressed concrete piles is usually from 12 inch (305mm) 66 in (1680mm). 12in (305mm) are usually squares piles and are used in the building structures.  66in (1680mm) diameter are cylindrical piles, used in the marine structures and bridges.

Advantages & Disadvantages of Precast Concrete Piles

Advantages

i. The main advantage of the pre cast concrete piles is that these piles compact soil. Thus, it increases the bearing capacity of the soil.
ii. These piles are available in different sizes, shapes, and lengths. They are available at the site according to the need. As a result, it increases the speed of the work.
iii. The position of the reinforcement in the pre cast concrete piles is not disturbed or changed
iv. Pre cast concrete piles have must faster foundation time and highest foundation quality.
v. Pre cast concrete piles are cost effective. These are cheap and suitable to use.
vi. The method to install the pre cast concrete piling is also environmentally friendly.
vii. These are the most economic form of deep foundation and can also be driven underwater.
viii. Pre cast concrete piles have the ability to withstand high pressure vertical loads. They can easily bear high tension loads.
ix. These piles are resistant to the biological and chemical action from the subsoil.

Disadvantages

i. Precast concrete piles are heavy in weight. They need special type of equipment for handling. Transportation and driving.
ii. These piles require sufficient care. If it is not provided, these may break during the transport or driving.
iii. These piles need time to be made, which means that these would not be available on short notice.
iv. The length of these piles is adjusted according to the transportation facilities.
v. These piles need extra reinforcement because of the transportation and driving stresses.
vi. If these piles are too long then it would be difficult to transport these. and it will be uneconomical to cut the pile.

Size Overview

Precast concrete piles are available in different sizes which ranges from 12 to 24 in, and in the measurements of length, these are up to about 100 fit. The load ranges from 40 to 60 tons.

Precast Concrete Piles different Size

If these are used for the larger sections, load will be increased and it can extend beyond 100 tons per pile.

When jetting is required for the installation of the pile, 3 to 4 in. diameter hole is formed along the central axis of the pile.

Cost Overview

The cost of the concrete piles varies from region to region on the basis of quality. A Chinese company has issued its price for 5-18m Concrete pile $1000/set.

The Precast-prestressed Concrete Institute (PCI) updated in 2021 that as the size of the panel increases the cost becomes lower, for example, erection of 100 square feet panel costs about $30 per square foot, whereas 200 square feet panel would cost around $20 per square feet.

Difference Between Precast Concrete Pile and Cast in Situ

The cost of the concrete piles varies from region to region on the basis of quality. A Chinese company has issued its price for 5-18m Concrete pile $1000/set.

The Precast-prestressed Concrete Institute (PCI) updated in 2021 that as the size of the panel increases the cost becomes lower, for example, erection of 100 square feet panel costs about $30 per square foot, whereas 200 square feet panel would cost around $20 per square feet.

Difference between Precast concrete pile and cast in situ

Taper of Precast Concrete Pile

Precast concrete piles are manufactured in uniform cross section or tapered. The tapered piles are usually made limited in length which is up to 40 ft.

The taper of precast concrete piles should not be more than 2cm per meter length.

Precast Concrete Pile Installation

The piles are usually driven in to the ground with the help of the hammers or vibratory drivers. Piles can also be inserted into the ground by jetting or partial auguring.

pile cap

Some types of hammers which are used for pile driving are:

  • Drop hammer
  • Single acting hammer
  • Double acting hammer
  • Diesel hammer
  • Vibratory hammer

For the installation process, first of all, the site is investigated and then piles are assessed based on strength and compressibility, etc. Groundwater level and artesian characteristics are also checked.

To determine the level of foundation, information is collected from nearby structures and experiences of the piles in the close area. Before the execution of the work, complete working diagrams are prepared.

Final Thoughts

Pile foundation is a safe, sound, and dependable foundation method; it is also the oldest method. A foundation usually consists of different layers of piles.

Pile is usually selected because of the following properties of the pile:

  • Nature of the Structure
  • Loading Conditions
  • Type of soil and its properties
  • Groundwater Table
  • Facilities for pile driving
  • Maintenance Cost

According to “Michael Tomlinson and John Woodward” (Author of Pile Design and Construction Practice)– Precast concrete piles principle is best suited for the marine structure and also proves very beneficial in the structures where timber piles are likely to be weekend by insects.