Mat Or Raft Foundation

The mat foundation which is sometimes known as a raft foundation is a combined footing that could cover the whole area under a structure supporting several walls and columns.

Mat or raft foundation.

Soilstructure mat or raft foundation simplifies the calculation of combined footings and mats or rafts. It is used where the supporting soil has low bearing capacity. Spreadsheets are hard to preserve and it is time consuming to calculate shear moment deflection and bearing pressures. Usually mat foundation is spread over the entire area of the structure it is supporting.

Now what is raft foundation. Raft foundation is a thick concrete slab reinforced with steel which covers the entire contact area of the structure like a thick floor. Raft foundation is actually a thick concrete slab resting on a large area of soil reinforced with steel supporting columns or walls and transfer loads from the structure to the soil. A raft or mat foundation is a large continuous rectangular or circular concrete slab that carries the entire load of the superstructure and spreads it over the whole area beneath the building.

Mat or raft foundation is a large concrete slab supporting several columns in two or more rows. The bearing capacity increased by combining all individual footings in to one mat since bearing capacity is proportional to width and depth of foundations. Mat foundations are sometimes preferred for soils that have low load bearing capacities but that is going to need to support high wall or column loads. A raft foundation also called a mat foundation is essentially a continuous slab resting on the soil that extends over the entire footprint of the building thereby supporting the building and transferring its weight to the ground.

Sometimes area covered by raft may be greater than the contact area depending on the bearing capacity of the soil underneath. In this project the soil profile shows that the bearing stress is around 100 kn m2. This program currently supports both the si units english units. When the raft foundation is supported on piles it is called a piled raft.

Raft foundation is mat foundation. It is considered as one type of shallow foundation and is useful in controlling the differential settlement.