Foundation (engineering)
Foundations are designed to have an adequate load capacity depending on the type of subsoil/rock supporting the foundation by a geotechnical engineer, and the footing itself may be designed structurally by a structural engineer. The primary design concerns are settlement and bearing capacity. When considering settlement, total settlement and differential settlement is normally considered. Differential settlement is when one part of a foundation settles more than another part. This can cause problems to the structure which the foundation is supporting. Expansive clay soils can also cause problems.
Rural Khmer house
Typology of Khmer house
The building consists of a supporting framework, which stands on individual foundations. There are no bracing or shear walls to strengthen the structure. The roof is built before wall cladding is applied.
The load-bearing piles of the building stand on single foundations. To comply with the specific conditions of the generally loamy soils, single foundations are laid in the following manner:
At the bottom of a 1 metre deep excavation several wooden poles of 1.5 – 2.00 metres length are rammed into the ground and then covered with a layer of compacted stone, followed by a hewn stone or prefabricated concrete slab, which provides the base for the pile. The excavation is then filled with soil. In a modern version the single foundations are linked with concrete slabs and prefabricated pillars extending to the upper floor are used.
For each pile, a single round hardwood tree trunk, such as .(…) is used. Extending from the foundation to the roof, and in the centre as far as the roof ridge, the piles, together with the horizontal joists, form the bearing structure of the house.