Foundation

A foundation gathers a building’s own weight, the loads of people and contents, and the effects of wind and earthquakes, and passes them safely into the ground. You never see it, yet it carries the building for its whole life; a fault in the foundation shows up above as cracks, settlement or tilting.

Types of foundation

The choice starts with the ground. A geotechnical survey establishes the soil’s bearing capacity, the groundwater level and the risk of settlement, and the structural design is based on those findings. Pad foundations are individual footings under each column, used for lighter buildings or on firm ground. Strip foundations run as continuous bands beneath walls or lines of columns. A raft foundation covers the whole footprint with a single thick slab, spreading the load over a wide area; it is common for reinforced concrete buildings in seismic regions such as Turkey. On weak soils, piled foundations carry the load down to a firm stratum deeper below. Waterproofing, drainage and blinding concrete beneath the foundation are specified alongside it.

The foundation from an architect’s view

The foundation affects the depth and level of a basement and can even shape the plan. On sloping sites, stepped foundations decide how a building sits on the land. That is why architectural design should be developed together with the geotechnical findings and the structural solution from an early stage.