Deep Foundations

In case, the strata of good bearing capacity is not available near the ground, the foundation of the structure has to be taken deep with the purpose of attaining a bearing stratum which is suitable in all respects. In addition there may be many other conditions which may require deep foundations for ensuring stability and durability of a structure. For example, the foundation for a bridge pier must be placed below the scour depth, although suitable bearing stratum may exist at a higher level. The most common forms of construction pertaining to deep foundations are
(a) Piles
(b) Cofferdams
(c) Caissons