Causes of failure of foundations are
(a) Unequal settlement of the subsoil.
(b) Unequal settlement of masonary.
(c) Horizontal movement of the soil adjoining the structure.
(d) Shrinkage due to withdrawal of moisture from the soil below the foundation.
(e) Lateral pressure tendency to overturn the structure.
(f) Action of atmosphere.
(g) Lateral escape of the soil below the foundation.