Foundation (engineering)

In building a foundation is (derived from the Latin " fundus " = ground ) regarded as a structure that is considered part of the general foundation. Such a structure each consisting of structural elements of the building industry ( boards, posts, beams, once even stones, sleepers and so on ). Are nowadays commonly used structural elements of reinforced concrete and steel.

Basic

Typically, the base is a structure attached to a lighter or sensitive structure to a solid support. Common foundations in the construction industry are the strip foundation or (now more often) exported in the reinforced concrete foundation slab. Foundations are usually heavier, more rigid and vibration- resistant than the mind or be secured to these components. They are intended to prevent an unintentional movement or deformation of the connected structure. Foundations are considered as an interface between different functional and structural areas. They often fulfill both the function of the supporting criteria and the fixed structure. Special forms are used for decoupling or separation of structures (eg elastic foundations or supports active ). Foundations may also be part of a larger structure, which in turn fundamentalised.

A foundation must be a safety against a shear failure have and must be rated for this failure mechanism.

Types of foundation

A distinction footings, strip footings and raft foundations.

• Footings are usually for individual columns or isolated components built like chimneys and the like.
• Strip foundations are the most common in Germany. You assume the burden of the supporting walls built on them, while non-bearing interior walls are usually built directly on the base plate. Their width often is twice the walls standing on them, the exact dimensions and possibly reinforcement arising from the carrying capacity of the subsoil. The foundations are often executed in the concrete strength class C20/25 or C25/30.
• Raft foundations or base plates are used when individual or strip footing due to high public easements are not economical. It can also be more economical at low loads use a baseplate as the labor cost is lower under certain circumstances. It then performs the entire floor plate of the foundation slab. A raft is always reinforced at the top and bottom. Laterally it is often beyond the outer edge of the ( basement ) walls. Before concreting the foundation plate, a thin layer of lean concrete cleanliness and / or a fixed PE film is introduced so that the reinforcement does not shift during concreting and the concrete is not mixed with the soil at the bottom of the pit. Lately foundation slabs are increasingly made ​​of steel fiber concrete especially in residential construction. The advantage is the much simpler production and also in price advantage over conventional reinforced concrete slabs.

The machine foundation as a special form of the foundation in building

A special form of the foundation, ie a structure as part of a foundation in foundation engineering, provides the machine foundation Represents the machine foundation with the purpose of the bearing (usually the lowest ) to bear part of stationary mounted machines, called the machine frame, or pick it. The machine frame - often cast in one piece - helps the individual, movable functional groups of the respective machine. Machine frames have no other task than wearing the functional groups ( motor, tool holder, control electronics, etc. ); they can account for 70-90 % of the total mass of a machine. Your large inertial mass, in combination with appropriate design beside a quiet machine running a high torsional stiffness and the required accuracy of machine operation sequence. The machine foundation allows the easy mounting of complicated geometries on a surface or in a building. Unlike foundations in construction machinery foundations allow some, albeit very limited extent, position changes. Because most machines are designed so that all major functional groups are fixed to the foundation and are constrained in their movement ability with each other.

Machine foundations are not to be confused with machine frames! The latter are to be connected as a constructed structure only there to machine design and building structure groups. Typical examples are:

• Cast-iron body with slide guide on a lathe;
• Steel column with cast steel base on a pillar drill.

A special form of machine foundation is the foundation pressure.

The plant is called by big strong engines or generators as machine foundation, the bearing design. These are often a bed of feathers; and these are supported on the actual foundation.