Piling

Construction technique for deep foundations

A pile driver in action

Piling is a fundamental technique in construction used to create deep foundations for structures. This method involves driving or drilling long, slender columns, known as piles, into the ground to provide support for buildings, bridges, and other structures. Piling is essential in situations where the surface soil's load-bearing capacity is insufficient to support the structure's weight.

Types of Piles

Piles can be classified based on their material, installation method, and function. The primary types include:

Material

• Concrete Piles: These are precast or cast-in-situ piles made from reinforced or prestressed concrete.
• Steel Piles: Typically made from steel pipes or H-sections, these piles are driven into the ground using pile drivers.
• Timber Piles: Made from tree trunks, these are one of the oldest forms of piling.
• Composite Piles: These combine different materials, such as a concrete core with a steel casing.

Installation Method

• Driven Piles: Installed using a pile driver, these piles are hammered into the ground.
  

  Pile driving process
• Bored Piles: Created by drilling a hole into the ground and filling it with concrete.
• Screw Piles: Installed by screwing into the ground, often used for lighter loads.

Function

• End-Bearing Piles: Transfer load to a strong soil or rock layer at the pile's tip.
• Friction Piles: Rely on the friction between the pile surface and surrounding soil to support the load.

Installation Techniques

The installation of piles involves several techniques, each suited to different soil conditions and project requirements.

Pile Driving

A pile driving machine

Pile driving is a common method where piles are driven into the ground using a pile driver. This technique is suitable for various soil types and is often used for steel and timber piles.

Drilling and Boring

In this method, a hole is drilled into the ground, and the pile is inserted or cast in place. This technique is ideal for areas with hard soil or rock layers.

Vibratory Driving

This method uses a vibratory hammer to install piles, reducing noise and ground disturbance compared to traditional pile driving.

Applications

Piling is used in a wide range of construction projects, including:

• Bridges: To support the structure over water or unstable ground.
• Skyscrapers: To provide a stable foundation in urban areas with deep soil layers.
• Marine Structures: Such as docks and piers, where piles are driven into the seabed.

Challenges and Considerations

Piling projects must consider several factors, including soil conditions, environmental impact, and noise levels. Engineers must conduct thorough site investigations to determine the appropriate piling method and design.

Related Pages

• Foundation (engineering)
• Geotechnical engineering
• Soil mechanics