by design8d » Sun Sep 29, 2013 8:12 am
From what I have read Mat and Raft foundations are the same. A raft/mat foundation is required where soils have low bearing capacity and have to support heavy structural loads. In high rises, raft/mat foundations can be several meters/yards thick. These types of foundations are used instead of deep foundations systems like piles when subsidence may be present. Think of them as a foundation system used on a building that would normally require a deep foundation system.