Stiff Foundation Mat

Mat foundation can be subjected to vertical loads horizontal loads and also to moments from column members.

Stiff foundation mat.

It is used to support storage tanks industrial equipment silos chimneys and. Buried utilities such as sewage and water pipes should have ductile connections to the structure to accommodate the large movements and settlements that can occur due to liquefaction. A mat foundation is in essence a stiff slab that acts as a single foundation element that covers the entire plan area of the structure. It is a continuous thick concrete slab on the soil that extends the entire footprint of the building and increases the soil bearing capacity power.

It is common to use mat foundation or deep basements. A mat foundation is used when the subsoil is weak and column loads are so heavy that the conventional spread footings cover more than 50 of the building area. As any shallow foundation a mat foundation has to be checked against bearing capacity failure and excessive total average settlement. Mat foundation is also known as the raft foundation.

Loads on raft or mat foundation. If i imagine this same strip footing placed under 3 columns spaced few meters away and acting as 3 point loads i would say that the foundation would behave a flexible since it will start bending. Ive always thought of strip footing under the wall whoes 45 degree disperse load line doesnt pass thru the bootom as a stiff foundation.