Types of foundation for buildings

In order to select perfect foundation of a building, consideration should be given on the various factors like soil conditions to the type of structure and loads from the building.

All these factors should be taken into consideration while selecting the foundation for developing strong building.

1. Loads from Building: The initial factor should be loads from building on the foundation. This load consolidates dead load and imposed loads on the buildings. Other loads like wind loads, earthquake loads, snow loads etc. should also be taken into consideration on the basis of location.

The quantity of loads are based on the type of structure, number of floors and material of construction. With the increased numbers of floors, the dead load and imposed loads also rise. Choice of material for construction like reinforced concrete or steel construction also provides effect on foundation. Reinforced concrete buildings apply greater loads on the foundation in contrast to steel structures.

Type of foundation and its base area is measured depending on the safe bearing capacity of structure and quantity of loads on foundation.

2. Type of Soils: Soil is formed by amalgamating solid particles, moisture and air. Types of soil range from clayey soil or expansive soil, sandy soil or loose soils etc. The soil adjacent to surface is known as top soil and under a depth of 300mm is known as sub soil. Usually subsoil is applied as base for foundation for small buildings.

However, soil testing is done for finding the nature of soil, depth of water table, type of soil, depth of different layers of soil as well as the bearing capacity of soil at various levels for large structures.

The soil testing is done for obtaining the following information:

• The nature and thickness of made-up ground/top soil above the sub-soil
• The nature, thickness and stratum depth of sub-soil
• A valuation of permissible bearing pressure
• Groundwater levels, chemicals in the ground, etc.
• Prevailing structures or hazards in the ground.

3. Type of Structure in Neighborhood: The selection of foundation for building construction is carried out on the basis of the type of foundation undertaken for the buildings in the adjacent buildings for similar types. Depending on the success or failure of foundations for such buildings, decision is undertaken for choosing the foundation.

4. Types of Foundations: Types of foundation like isolated foundations, combined footings, pile foundations and raft or mat foundations etc. depend on the type of soils and loads from the buildings.

Ref: theconstructor.org