# Response Spectrum Wizard : Eurocode 8 (1994)
The Eurocode 8 : 1994 spectrum is defined by a set of parameters defined in the code.
Subsoil Class
Sites are classed depending on the subsoil as A, B, or C as described in Part 1-1 Section 3.
Ratio of Ground Acceleration to Gravity (
The parameter α is used to characterise the seismicity of the site.
Spectrum
The spectrum can be either an elastic spectrum or a design spectrum.
Structure Damping Ratio (
The spectrum values to use depend on the level of damping in the structure as expressed in the damping ratio. Elastic spectra only.
Behaviour (
A behaviour factor is defined which adjust the level of the spectral values. Design Spectra only.