Foundations provided for machines are called machine foundations.
These foundations have to be specially designed taking into account the impact and vibration characteristics of the load and the properties of soil under dynamic conditions. Thus the design of foundations of Turbines, Motors, Generators, Compressors, Forge hammer and other machines having a rythmic application of unbalanced forces require special knowledge of theory of harmonic vibrations.
All the above consideration are made in the design of machine foundations because inertial forces of rotating elements of machine contribute dynamic loads in addition to their static loads. Moreover, the machinery vibration influences adversely the foundation supporting soil by densifying it which may result differential settlement of the foundation.
Machine foundations must fulfil the following design requirements.
- A machine foundation should be safe against shear failure.
- It should not settle excessively under static loads.
- There should be no resonance due to dynamic force i.e the natural frequency of the foundation soil system should not be coincide with the operating frequency of the machine.
- The amplitude at operational frequency of the foundation system must be within telerable limits.
- The vibrations of the foundation soil system must not annoying to the workers working in that area.
- It should not create bad effect on the other precision machines and instruments.
Types of Machines Foundations
Machine foundations are broadly classified into the following three types, depending upon the type of machines for which they are provided:
- Reciprocating type Machines Foundations.
- Centrifugal type Machines Foundations.
- Impact Type Machines Foundations.