A solid and strong base is the key to constructing a safe and long-lasting building. It helps prevent problems like cracks, sinking, or uneven floors. One of the most reliable ways to achieve this is through a deep foundation. It reaches down to stronger soil layers, giving the building long-term strength and support.

There are various deep foundation methods such as bored piles, driven piles, CFA piles, and screw piles. Each method works best in different soil conditions and project types. For example, bored piles are good for deep support, while CFA piles cause less disturbance. Therefore, choosing the right method is crucial to ensure structural integrity.

In this guide, we will explain different types of deep foundation methods and their effectiveness with different soil types.

Continuous Flight Auger or CFA Piling

In this method, a hollow auger drills into the ground and concrete is pumped through it while the auger is pulled out. It is fast, causes less noise, and is ideal for sites with limited access or near existing buildings. It works well in soft to medium ground, making it a good choice for projects needing quick and clean foundation work without much disruption to nearby structures.

Contractors often go for CFA piling rig hire to keep costs lower and meet tight deadlines. It is a specialised machine used to install deep foundations in construction projects.

Bored Piles

Bored piles are made by drilling a hole into the ground and filling it with concrete and steel reinforcement. This method is used when the soil is hard or when the foundation needs to go very deep. It’s perfect for large commercial buildings or bridges where strong support is needed.

Bored piling is also a quiet process, which helps when working in urban areas. It provides strong load-bearing capacity and works well in a wide range of soil types, including mixed or layered ground.

Driven Piles

Driven piles are long concrete, steel, or timber columns that are hammered into the ground using heavy equipment. It is one of the fastest methods as it doesn’t require drilling. These piles are good for sites with firm soil layers close to the surface.

This method is ideal for bridges, marine structures, and industrial buildings. It helps save time but can be noisy and cause vibration, so it’s not always suitable for residential or crowded areas.

Screw Piles

Screw piles are metal shafts with helical blades that are screwed into the ground using hydraulic machinery. It is also a fast method, requires no curing time, and is perfect for small to medium-sized buildings. It works best in softer soils and is often used in lightweight structures like walkways or small commercial buildings.

Unlike other piles, they are easy to remove or reuse foundations in temporary structures. They are known for causing minimal ground disturbance and can be installed in almost any weather.

Underpinning

Underpinning is used when an existing foundation is not strong enough or has shifted. It involves digging beneath the current base and adding deeper support, such as concrete or mini piles, helping strengthen the foundation without having to rebuild the structure.

It is usually allowed for upgrades or extensions and is often used in commercial renovations. Though, it is a slower method, essential for keeping existing structures safe and stable.

Micropiles

Micropiles are small-diameter piles drilled and filled with concrete and steel reinforcement. They are used in areas with limited access or where vibration must be kept low. This method is great for strengthening existing foundations or working in tight urban spaces.

These piles are quite strong and can carry heavy loads despite their size. Therefore, they are often used in historic buildings, bridges, and projects on uneven or rocky ground.

Jacked Piles

Jacked piles are driven into the ground using hydraulic jacks instead of large hammers or drills. It is mostly used under existing buildings where heavy machinery cannot be used. This method is quiet, causes less vibration, and can be controlled more easily than traditional driven piles. They offer precision and are a good choice for areas where access is limited or the ground is weak.

Secant and Bored Pile Wall Systems

A bored pile wall is made by drilling closely spaced piles in a row to form a solid wall. It is often used in deep excavations where soil needs to be held back safely. The bored piles are reinforced and sometimes tied together with beams or anchors. This method is suitable for sites with nearby structures or roads, as it limits ground movement and keeps the site safe.

Key Takeaway

All these methods are used to create deep and strong foundations that support almost all types of buildings. Each method has its own benefits and is suitable for different ground conditions, project sizes, and site limitations. So, you can choose any one of them depending on the type of soil, load requirements, and the overall design of the structure.