Selection of particular type of building foundation is affected by various factors which are explained below:
1. Type of soil
Shallow foundation are preferred if the soil close to the surface has good bearing capacity. If the soil is not capable of supporting structural loads then deep foundation are required.
2. Load from Superstructure
If the structural loading is relatively small, shallow foundation may withstand load from superstructure. In case of high rise building with intense loading, deep foundations may become the only choice.
4. Settlement
If the foundation settlement is not within the allowable limit, then choice of foundation type may vary accordingly.
5. Property Line
Due to restriction of property line, a column may have to be placed at the edge of footing creating an eccentricity. In such case, a cantilever footing (or strap footing) should be provided.
6. Stress Overlap
If the spacing between column is very small, then the stress from independent footings might overlap and become larger than allowable limit. Thus, combined footing have to be preferred.
7. Local Building Codes & Regulations
Building codes and regulations set by local authorities dictate the minimum standards and requirements for foundation design and construction. Compliance with these regulations is essential to ensure the safety and stability of the building.
8. Environmental Factors
Environmental conditions, such as seismic activity, flooding etc need to be considered when selecting a foundation system. Regions prone to earthquakes, for example, may require specialized foundation designs to withstand the seismic forces.
9. Type of Structure in Neighborhood
High rise buildings may cause uplift of nearby building due to soil heaving. So, a pile foundation may be the solution to safely transfer load to the deep strata and not to harm the nearby structures if any.
10. Other Factors
- Construction cost and time
- Service life of structure
- Safety Margin
- Ground water table
- Site topography
- Depth of hard strata