Abstract:
The vibration isolation of buildings housed with sensitive equipment is always a challenging one due to the
stringent vibration criteria imposed on them. The paper presents a case study on the vibration isolation scheme
adopted for an important building of space research agency. The vibration levels in the building had to follow
the vibration criterion which is in the form of a set of one – third octave band velocity spectra, expressed as
vibration criterion curves. Various sources that can generate vibrations in the building were identified and
assessed. The external sources and the internal sources of vibration were analyzed and the possible limits of
vibrations were evaluated. The selection procedure of design frequency, which is the significant step in the
design of vibration isolation trench under the passive isolation scheme, is explained. Numerical simulations were
developed to evaluate the influence of trench parameters on the amplitude reduction of Rayleigh waves propagating
across the trench. Based on the results from numerical simulations, the vibration isolation trench was
designed to reduce the amplitudes of vibrations produced from external and internal sources.
