Response Spectrum Wizard : Eurocode 8 (2004)

The Eurocode 8 : 2004 spectrum is defined by a set of parameters defined in the code.

Subsoil Class

Sites are classed depending on the subsoil as A, B, C, D or E as described in Part 1-1 Table 3.1.

Ratio of Ground Acceleration to Gravity ()

The parameter agR is used to characterise the seismicity of the site.

Importance factor ()

The importance factor allow am amplification for topographical effects depending on the type of structure.

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 adjusts the level of the spectral values. A separate value, qd, can be applied to scale the displacements. If qd is not specified the value is q is used instead. Design Spectra only.

Lower Bound Limit ()

A lower bound factor sets a minimum level below which the spectrum cannot fall. Design Spectra only.