When is a mat foundation typically used?

A mat foundation, also known as a raft foundation, is typically employed in situations where the soil bearing capacity is low. This type of foundation spreads the weight of the structure over a larger area, which helps to distribute the load more evenly and reduces the pressure exerted on the underlying soil. In cases where the soil cannot support significant loads due to its inherent weaknesses, a mat foundation provides the necessary support by increasing the footprint of the foundation.

When soil bearing capacity is low, conventional shallow foundations may not be sufficient, and deeper foundations could be more costly or challenging to implement. A mat foundation effectively addresses these issues by minimizing the potential for differential settlement and enhancing stability. This design is especially advantageous for heavier structures, as it allows for the construction without the risks associated with inadequate soil support.

In summary, the use of a mat foundation is particularly suited for conditions with low soil bearing capacity, ensuring that the building remains stable and secure.