Mat Slab Foundation Design

The construction of mat foundation.

Mat slab foundation design.

Two way slab and beam. It is used where the supporting soil has low bearing capacity. The mat foundation is also reinforced with many bars inside it which run perpendicular to each other. Although mat foundations are more difficult and more costly to design than individual spread footings they can be used effectively.

Mat or raft foundation is a large concrete slab supporting several columns in two or more rows. Typically reinforced with a double layer of rebar throughout its pad a mat slab is capable of bearing loads at virtually any point and distributing heavy loads across an expanse of weak subsoil. Mat foundation is constructed as a large slab which works as the base for the building. In this type of mat foundation beams are placed in perpendicular directions and all the beams are connected by rcc slab.

The bearing capacity increased by combining all individual footings in to one mat since bearing capacity is proportional to width and depth of foundations. The building then rests on this foundation leading to lesser contact with the land and hence more strength and stability. It is used to support storage tanks industrial equipment silos chimneys and various tower structures. A mat foundation is a thick reinforced concrete slab supporting arrangements of columns or walls in a row or rows and transmitting the loads to the soil.

Two way slab and beam raft foundation is suitable when the columns are carrying unequal loads and the spacing is large between them.