TYPES OF FOUNDATION

Foundation is structural part of a building on which a building stands. Foundation transmit and distributes it on load or imposed load to the soil in such a way that the load bearing capacity of the foundation bed is not exceeded. The solid ground on which the foundation rest is called foundation bed. There are various types of foundation.

FUNCTIONS OF FOUNDATION

Distribution of loads
Stability against sliding and overturning
Minimize differential settlement
Safe against undermining
Provide level surface
Minimize distress against soil movement

CLASSIFICATION OF FOUNDATIONS

1. Shallow Foundation

2. Deep Foundation

1. SHALLOW FOUNDATION

A shallow foundation is a type of foundation that transfer load to the very near the surface. Shallow foundation are those foundation in which the depth at which foundation is placed is less than the width of the of foundation (D<B). This foundation used when the surface soil are sufficiently strong and stiff to support the imposed load. They are generally unsuitable in weak and highly compressible soil. Shallow foundation itself can be various types-

Pad Footing or Column Footing

Isolated Footing
Combined Footing

Cantilever or Strap Footing
Mat/ Raft Footing
Wall Footing

2. DEEP FOUNDATION

Deep foundation are those foundations in which the depth of the depth of foundation is greater than its width (D>B). The D/B ratio is usually 4-5 for deep foundation. The deep foundation transmits the load of the super structure vertically to the rock strata lying deep. Deep foundation are used when the shallow foundation can not support the load of the structure. The deep foundation can be further classified into following types-