Foundation is used to support a building or structure and transmits loads directly to the underlying soil or rock.
It must satisfy two fundamental requirements:
•Firstly, it must provide an adequate factor of safety against failure of the supporting strata.
2. Building Foundation
Foundation is used to support a building or
structure and transmits loads directly to the
underlying soil or rock.
It must satisfy two fundamental requirements:
• Firstly, it must provide an adequate factor of safety against failure of the
supporting strata.
• Secondly, any resulting settlement, and in particular differential
settlement, should not be detrimental or interfere with the function of the
structure.
3. Shallow vs Deep Foundation
Shallow foundations are constructed relatively close to the ground
level. Shallow foundations can only be used where the soil at that
level is capable of adequately supporting the load.
Deep foundation is used to transfer loads from a structure above
ground through upper weak strata of soil to a more competent one
at depth, beyond which shallow foundations become both
impractical and uneconomic.
4. Concrete foundation
The type of concrete foundation depends on the area the foundation will
be located on and the type of structure that will be placed on it.
Adjustments to the form of a foundation based on the footings cannot
be made after concrete is poured. Because concrete is very heavy, one
should be sure that the formwork is strong and firmly in place.
The foundations should be covered from rain as it can cause
depressions in the concrete and cause your foundation to be uneven.
Regardless of the type or how you build a concrete foundation, the
most common problem facing homeowners and contractors is a
concrete foundation crack.
A concrete foundation crack is perfectly normal as 66% of all concrete
foundations crack within the first year. The major reason for cracks is
concrete shrinkage and a settling concrete foundation.
5. Design Concerns: Settlement
The primary design concerns are settlement and bearing capacity.
When considering settlement, total settlement and differential settlement
is normally considered.
Differential settlement is when one part of a foundation settles more
than another part.
This can cause problems to the structure the foundation is supporting.
6. Design Concerns: Bearing Capacity
Foundations are designed to have an adequate load capacity with
limited settlement by a geotechnical engineer, and the footing itself may
be designed structurally by a structural engineer.
Inadequate foundations in muddy soils below sea level are a primary
cause for houses to subside.
7. Remember, you only get one chance to protect your home right
the first time.
Do it right, do it once, do it forever.