Foundations are a vital part. Any settlement or failure will result in a catastrophic structure failure that prompt losses of life and damages of properties. Foundations categorized into the shallow foundation and deep foundation.
1. Shallow foundations
Shallow foundations are the most economical foundation system, and they used when the soil bearing capacity is sufficient to carry imposed structure loads. Shallow foundations have a limited ability, and they can tolerate small vertical loads and lateral displacement. The uses of shallow foundations for bridges are limited due to high vertical loads and considerable span length.
The main component of shallow foundations is footing, which transfers the loads from columns or wall to surrounding soil. There are different footings, such as isolated, combined, wall, and raft footing.
Footing shall be designed to distribute the loads from structure to surrounding soil. Moreover, to resist punching shear, excessive or differential settlement and bending moment at the face of the column.
2. Deep foundation
Deep foundation used for significantly high vertical loads or when the soil bearing capacity is low, piles are used widely in high rise building and bridges. Piles possess a higher capacity and ability to transfer the loads from structures to weak soil without failure.
Piles are a long and slender structural member. The main function is to transfer loads to the surrounding soil. The mechanism of transferring the loads in piles differs significantly from a shallow foundation. piles transfer the loads using two mechanisms
1. Friction pile: transmits the load to surrounding soil by adhesion or friction between the surface of the pile and surrounding soil.
End bearing pile: transmits the load from pile toe too hard strata.
2.Pile load transfer mechanism