Pile Foundation: A Guide From Excavation to Final Pour

In construction, what happens underground matters just as much as what stands above. Whether you're building a home as per a 2bhk house plan or a higher multistoreyed house, your choice of foundation decides how safe and long-lasting the structure will be. So, in a situation where the soil beneath is soft or waterlogged, the solution is almost always a pile foundation.

What is a Pile Foundation?

A pile foundation is a type of deep foundation that is used when surface soil is unable to strongly support the structure’s load. Piles, unlike shallow foundations, are not built wide at the base. They are driven or drilled deep into the ground in order to reach stronger rock or soil layers.

They are necessary for buildings on soft clay, loose sand, and in areas that have frequent waterlogging. Piles help to transfer the load vertically into deeper, more stable ground, and this makes them so important.

The Different Types of Pile Foundations

Here are the most common types of pile foundations categorized by materials and construction method:

• Bored Piles

These are cast-in-place piles. A hole is drilled into the ground, then filled with concrete. Ideal for urban areas where noise and vibration from hammering are a concern.

• Driven Piles

These are pre-cast concrete or steel piles hammered into the ground using machinery. They’re fast to install and offer high load-bearing capacity, but the process can be noisy.

• Screw Piles

These work like giant screws which are rotated into the ground and work well for light structures or areas with limited access. Quick to install and easy to remove or reuse.

• Under-Reamed Piles

These are like bored piles but have a bulb-shaped enlargement at the bottom. They’re great for expansive soils that swell and shrink with moisture changes.

• Composite Piles

A mix of materials like concrete and steel used together in a single pile. Often chosen when different parts of the pile are exposed to different conditions underground.

Each of these types serves a specific purpose. The key is to match the pile type to the soil conditions and building load and not just pick based on cost or convenience.

Which cement is used for pile foundation?

When choosing cement for a pile foundation, the decision is usually based on what each type brings to the table rather than claiming one is better than the other.

OPC (Ordinary Portland Cement) is often used because it sets quickly and gains strength fast, which can be important if you need the foundation to stabilize early on.

On the other hand, PPC (Portland Pozzolana Cement) gains strength more gradually, but this slower pace can be an advantage in the long run, especially when durability and resistance to harsh weather come into play.

Additionally, in environments where the soil or water might be aggressive or rich in sulphates, Sulphate Resisting Cement might be preferred to guard against chemical attacks.

Essentially, the right cement for a pile foundation depends on the specific requirements of the project and the conditions at the site.

What grade of concrete is used in pile foundation?

For most building projects, the answer starts at M25. If you’re working on larger loads or taller structures, M30 and above might be needed.

The right grade isn't a one-size-fits-all answer but instead, it depends on your structure’s load and soil report.

What materials are used for pile foundation?

Besides the right type of cement or the perfect grade of concrete, there are other materials too that are very important for pile foundation. Here's a quick look at some of the most essential materials that are usually required:

• Fine and coarse aggregates

• Clean water

• Steel reinforcement cages

• Drilling equipment and casing pipes

• Proper disposal of excavated soil

Each component plays a part in creating a foundation that doesn't shift or crack.

Minimum Pile Size and its Importance

In general, 6 numbers of vertical bars shall be used for a circular pile and minimum diameter of vertical bar shall be 12 mm. The minimum diameter of a pile foundation generally starts around 300 mm for residential use. However, depending on load and soil bearing capacity, it may go up to 600 mm or more. Bigger diameters are not about visual weight but instead they are about distributing structural loads safely and in a uniform way.

Foundations are not something that can be compromised. A pile foundation built with the right materials, the best cement, and attention to site conditions sets your structure up for decades of stability. When you buy materials for the job, a bulk cement order is usually better for quality consistency, ensuring your team is not waiting mid-pour. So make sure to choose trusted building materials suppliers and take the right decisions for your construction project.