Types of Pile Foundation

 

Piling foundations consist of deep foundation systems which are the most commonly used to convey building loads to lower soil or rock layers and are helpful in the transfer of loads in the presence of weak material at the surface level. Such foundations help to maintain the structural integrity of the building even in the presence of dynamic loads. To enhance the structural integrity of the building, the building loads are distributed across a larger area using piles. Piles are made of different materials and are classified on the basis of the material used and the way loads are transferred.

1. Classification by Material

a. Concrete Piles

Concrete piles are one of the frequently used types in construction industries .They are further divided into:

• Precast Concrete Piles: Manufactured off-site and brought to the construction site. They are suitable where uniform quality and precise dimensional control are required.
• Cast-in-situ Concrete Piles: : In this type, concrete is placed and cured directly within a prepared borehole in the ground. They are suitable for sites with limited access or tight overhead space clearance.

Advantages:

• High durability
• Can handle large loads
• Resistant to corrosion when reinforced

b. Steel Piles

Made from rolled steel sections like H-piles, I-beams, or pipe piles, these are driven into the ground using vibratory hammers.

Advantages:

• High load-carrying capacity
• Easy to splice or cut
• Suitable for very deep foundations

c. Timber Piles

Used historically and still applied in some small-scale or temporary constructions. Typically made from straight tree trunks.

Advantages:

• Cost-effective for light loads
• Environmentally friendly
• Easy to handle and install

Disadvantages:

• Susceptible to decay unless treated
• Limited length and load capacity

d. Composite Piles

Utilize composite construction by integrating materials like concrete and steel or concrete and timber. These piles aim to utilize the benefits of each material.

For example, a steel pile might be used in the upper section exposed to water, while a concrete lower section is embedded in stable soil

2. Classification by Installation Method

a. Driven Piles

Driven piles are prefabricated piles type that are vibrated or hammered into the ground using pile-driving equipment.

Types:

• Timber
• Precast concrete
• Steel

Advantages:

• Quick installation
• No curing time required
• Quality can be inspected before installation

Disadvantages:

• Noisy and causes vibrations
• May not be suitable in urban areas or near sensitive structures

b. Bored (Drilled) Piles

This type of pile constructed by drilling a hole into the ground and poured it with concrete. Reinforcement is erected before the concrete is poured.

Advantages:

• Quiet and vibration-free process
• Ideal for urban settings
• Can be installed in various soil conditions

Disadvantages:

• Requires specialized equipment
• Quality depends on site management

c. Screw Piles (Helical Piles)

These piles have a helical blade at the end and are screwed into the ground like a large screw. Typically used for lightweight structures and in areas with limited access.

Advantages:

• Fast installation
• Minimal vibration
• Immediate load-bearing capability

3. Classification by Load Transfer Mechanism

     a. End-Bearing Piles

• Load transfer in these piles occurs primarily through end bearing on a strong underlying stratum.. Most of the load is transferred to the ground through end bearing at the pile base.
  • Suitable for sites where a hard stratum is located at a certain depth.
  • Act similarly to a column transferring load from the structure to the firm layer below.

  b. Friction Piles

  Friction piles are employed where no hard bearing stratum is present, transferring loads to the surrounding soil through surface friction along the pile shaft.
  • The entire surface of the pile contributes to load-bearing.
  • Typically longer than end-bearing piles.

  c. Combination (End-Bearing + Friction) Piles

  Many piles utilize a combination of end-bearing and skin friction for efficient load transfer, a method commonly adopted in complex soil conditions where multiple load paths enhance performance.
  
  4. Special Types of Piles

  a. Mini Piles (Micro piles)

  Small-diameter piles used in restricted spaces or for underpinning existing structures.

  b. Sheet Piles

  Thin, interlocking sheets driven to form a continuous wall, typically used for earth retention rather than vertical load support.

  c. Tension or Uplift Piles

  This type of pile designed to resist uplift forces caused by water pressure, wind, or overturning moments. Used in towers and offshore structures.

  The foundation plays an important role in ensuring structural stability and safety, especially under the state of hard soil. The alternative with the correct number of pieces depends on factors such as soil types, load requirements, environmental conditions and budget restrictions. Intensive ground technical inspection and structural analysis are important for determining the best frequency system for each construction project.