What is a Machine Foundation?
​A foundation provided below the superstructure of a vibrating and/or rotating machine for installation is known as machine foundation. It essentially consists of a mass of concrete. Designs of machine foundations involve consideration of static load and kinetic forces.

The load of the machine is the static load which is of minor importance in the design of a machine foundation. The moving parts of the machine develop inertia forces which are the major forces to be considered in its design. The kinetic or inertia forces are periodic and vibratory in nature, the magnitude of which depends on the type of machine.
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​There are four types of machine foundations generally used: Block Type, Box Type, Wall Type, Framed Type - as shown below.
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Principles of Machine Foundation Designs:
  • Machine foundations should be isolated from the adjoining parts of the building by leaving a gap around it to avoid the transmission of vibrations. The gap is filled with suitable insulators or dampers.
  • The foundation should be stiff and rigid to avoid possibilities of tilt in it.
  • In its static state, the resultant forces acting on a machine foundation should pass through the center of gravity of the contact area of the base.
  • The weight of the foundation block should be adequate. It should be able to absorb vibrations and resist resonance between adjoining soils and the machine. The weight of the foundation block may be assumed at roughly 2.5 times the weight of the machine.

​Design Criteria for Machine Foundations:
  • The machine foundation should be safe from a bearing capacity failure under static and dynamic loads.
  • The settlement must be less than prescribed.
  • The dynamic amplitudes of the machine foundation soil system must be within the prescribed limits under service conditions.
  • There should be no resonance, i.e. the natural frequency of the machine foundation soil system should not coincide with the operating frequency of the machine.
  • Preferably, the center of gravity of the machine should lie in the same vertical line as the center of gravity of the foundation system.