Raft Foundations

Where ground is not suitable for screw piles, driven piles or micro piles, FLI can design and install raft foundations to support both light and heavy weight structures, in Railway, Highway, Telecommunications or construction markets. 

Use of screw piles with concrete rafts

Raft foundations traditionally consist of a reinforced poured-concrete slab. Depending on the project, a raft foundation may also be stiffened by incorporating reinforcing bars or beams, with holding down anchors pre installed for attaching the structures. For certain purposes, concrete caps can also be complemented by additional foundations such as helical screw piles.

 Raft Foundation Variations

If the ground is unsuitable for a concrete Raft, FLI Structures has designed the following solutions to overcome this problem -

• Plain slab with reinforcing bar
• Plain slab with separate wide strip foundation
• Plain slab with stiffened edge (and a deeper integral beam)
• Cellular raft foundations
• Piled raft foundations
• Piled ground beams

Advantages of raft foundations

• Loads are spread over the whole area of the structure.
• Differential settlements are reduced.
• A concrete raft foundation avoids interaction of individual pad foundations (e.g. for columns) where these would otherwise be too close together.

For more information, please contact us.