Building a Strong Base: Exploring Different Types of Foundations

What are the Types of Foundations in Construction?

Foundations in construction are classified into two main types: shallow and deep foundations. Shallow foundations, such as individual footings, combined, strip, and raft foundations, are typically used for light structures with good soil-bearing capacity. 

Deep foundations, like pile foundations and drilled shafts or caissons, transfer the heavy load to deeper, more stable soil layers and are used when the surface soil's bearing capacity is inadequate. 

Also Read: Building Foundations

4 Types of Shallow Foundations

As discussed, shallow foundations are used in construction, typically located near the ground's surface and spread over a large area to support structures. Here are a few types of them: 

1. Individual Footing or Isolated Footing

The individual or isolated footing is the simplest and most common type of foundation. They are constructed to support a single column. They are also known as a pad foundation, and their shape is typically square or rectangular, calculated based on column load and soil bearing capacity.

Advantages:

• Economical and straightforward in design

• Ideal for supporting structures with a clear load path and predictable loads

Disadvantages

• Not suitable for heavy structures or when soil conditions are variable

• Supports only a single column

2. Combined Footing

When columns are closely spaced such that their footings overlap, a combined footing is constructed. It shares attributes with isolated footings but differs in structural design, usually taking a rectangular shape. Specialised techniques like catavilier foundation footing may be employed in complex scenarios to mitigate issues and enhance performance.

Advantages:

• Efficiently supports multiple columns

• Distributes loads evenly

• Useful in confined spaces

Disadvantages:

• More complex and costly than individual footings

• Requires detailed engineering to ensure load balance

3. Spread Footings or Strip Footings

Spread or strip footings feature a broader base than typical load-bearing walls, distributing the building's weight over a larger area. These are types of foundations used for walls, individual columns, and bridge piers where the soil layer is within 3 metres from the surface.

Advantages:

• Provides better stability by spreading the load

• Suitable for structures where the bearing soil layer is close to the surface

Disadvantages:

• Not applicable on soils at risk of water flow that might cause scour or liquefaction

• Limiting their use to stable ground conditions

4. Raft or Mat Foundations

Raft or mat foundations cover the entire building area, supporting heavy loads from columns and walls. This type of foundation is chosen to prevent differential settlement of footings, acting as a single mat for all structural elements.

Advantages:

• Ideal for structures with high loads on columns and walls

• Minimises differential settlement across the foundation

Disadvantages:

• Complex and expensive to construct

• Requires significant excavation and concrete work, making it suitable for select, heavily loaded structures

2 Types of Deep Foundation

Deep foundations are used when shallow foundations cannot provide adequate support due to significant structural loads or poor soil conditions at shallow depths. Let's delve into the two types of deep foundations below:

1. Pile Foundation

Benefits of Vastu Shastra in West Facing Home Plan

Following Vastu Shastra's principles for a west-facing house plan brings many benefits, ensuring the structure harmoniously aligns with universal energy flows. This careful consideration in the house design, particularly for west-facing properties, attracts prosperity, health, and happiness by optimising the entrance and room placements for natural element interaction. 

The strategic location of key areas like the kitchen, bedrooms, and living spaces under Vastu guidelines enhances house harmony, improves financial stability, and supports well-being. By leveraging the advantages of directional energies in a west-facing house vastu plan, residents can enjoy a sanctuary of peace, fostering a positive and balanced environment. This integrative approach to house design for west-facing residences is a blueprint for holistic and prosperous living.

Pile foundations comprise long, slender columns typically made from steel, concrete, or wood. This type of foundation is driven into the ground or bored into place, reaching depths where the soil has sufficient bearing capacity and stiffness to support the structure's loads. 

Advantages:

• Can reach deep, stable soil layers or bedrock

• Suitable for both tensile and compressive loads

• Ideal for offshore and bridge structures, high-rise buildings, and areas with poor soil conditions

Disadvantages:

• Installation can be noisy and cause vibration, potentially impacting nearby structures

• Requires specialised equipment and expertise for installation

• Determining the correct length and load capacity can be complex and requires detailed soil analysis

2. Drilled Shafts or Caissons

5 Tips for Effective Foundation Construction

The successful laying of a foundation in building construction is critical for the longevity and stability of the project. Here are essential tips to ensure a solid foundation:

1. Understand Soil Types

Different types of soils have varying load-bearing capacities. You should conduct soil tests to determine the type you're working with and adjust your foundation design accordingly.

2. Ensure Accurate Layout

Precision in the layout of the different types of foundation is crucial. Use professional surveying equipment to mark exact dimensions and orientations, ensuring the foundation aligns correctly with the building plans.

3. Water Management

Water can undermine foundations, causing settling or shifting. To protect the foundation's integrity, plan for proper drainage away from it and use waterproofing measures to prevent moisture intrusion.

4. Choose the Right Type of Foundation

Select a foundation type (e.g., shallow vs. deep) based on soil analysis, building load, and environmental conditions. Consider local building codes and practices.

5. Quality Materials

Use high-quality concrete and reinforcing materials to ensure the foundation's durability. Compromising on material quality can lead to future structural problems.