1 BUILDING ELEMENTS FOUNDATIONS Function of foundations Foundations transfer the total loads from the structure to the ground providing stability to the building. Foundations can be mainly classified into two categories depending on the depth at which the foundation is constructed: : used for small, light buildings (1 or 2 meters deep); foundations shallow : used for large, heavy buildings such as skyscrapers (from 5 to 25 metres). They must the building to the ground. deep foundations anchor A properly designed foundation will limit , that is the normal tendency for a new building into the ground . Most soils are a mixture of earth, air and water, so, when the building load is on the soil, the air and water are and the soil consolidates. settlement 1 to sink 1 exerted driven out A foundation is usually wider than the element which is supported, so the load is over a greater area and the actual weight of the building does not the of the soil. Placing ensures the foundation to remain stable. spread exceed safe bearing capacity steel reinforcement Construction steps The first step in constructing foundations is the considering the type of soil, the and the depth of underground water. excavation frost line Then are placed by pouring into wood or steel forms positioned under the frost line. This is essential in cold climates because the water in the soil around the foundation can freeze and expand, so damaging the foundation. footings concrete Shallow foundations of residential buildings are supported on that are visible during the early stages of work. low-rise open footings Deep foundations for buildings include . A pile is basically a long cylinder of a strong material such as concrete that is pushed into the ground so that the structure can be supported on the top of it. During the foundation works, excavations for connecting the are usually required and are at the same time. high-rise piles technical systems dug WARM UP How deep do you think the foundation of your house could be? Tick ✓ the box and justify your choice. ( ) 1 - 2 m. ( ) 3 - 4 m. ( ) 5 -10 m. ( ) more than 10 m DO Name one of the most famous Italian historical buildings with settlement problems. 1 MORE The most common sign of settlement is the occurrence of cracks on the structure at an angle of 45˚, usually around the openings (doors, windows). 1 Deep foundations Shallow foundations