The object of research in the article is the vibroisolated foundation of a high-power turbine unit (1000 MW). World energy is developing rapidly today and there is a need to build energy facilities in areas of high seismicity. The acute question is the lack of a comprehensive methodology for calculating and designing earthquake-resistant foundations of turbine units. The article proposes a general procedure of actions aimed at increasing the seismic resistance of the foundations of turbine units. Implementation of the proposed methodology was carried out on a specific example of a vibroisolated foundation: the dependences of seismic accelerations and displacements were obtained for different variants of seismic isolation. Application of the above technique allows to reduce seismic acceleration on capacitors by more than 2 times, seismic movements of capacitors by more than 3 times.