RCC Footing Details And Types

The following two types of R.C.C. footings generally found :- 1. One way reinforced footings, 2. Two way reinforced footings.

One Way Reinforced Footing: These footings are intended for the walls. Under these types of footings, main reinforcements are provided in the transverse direction of wall. In longitudinal directions, only nominal reinforcement exists.

Two Way Reinforced Footings:
Two way reinforced footings are mainly arranged for columns.

Besides, there are other common types of footings :-

Isolated Column Footings: If separate footings are arranged for each column, it is known as isolated column footing. On the basis of the area, the size of footing is decided to securely disperse the load of the columns over the soil.

These footings are constructed over a 100 to 150mm bed concrete. The design engineers determine the reinforcements and thickness of footing. Thickness of the footings may be consistent or changeable.

Combined Footings: Common footings are intended for two columns. This type of footing is generally provided when a column is very adjacent to the boundary of the property and therefore the footing can’t be provided much beyond the column face.

The footing should be created for transmitting loads from both columns carefully to the soil. The two columns may or may not be attached with a strap beam.

Continuous Footings: If a footing is common to in excess of two columns in a row, it is defined as continuous footing. This type of footing is suitable when the columns in a row remain at a close range or SBC of soil is low.

Mat Footing/Raft Footing: If the load on the column is extreme (Multistorey columns) or the SBC of soil is low, the sizes of isolated columns should be accommodated so that they overlap with each other. Such footings are called raft footings.

If the beams are arranged in both directions over the footing slab for joining the columns, the raft foundations are known as grid foundation. The most striking benefit of such footing is that settlement is consistent and consequently unwanted stresses are not formed.