Local Seismic Response RSL III – Software for the evaluation of third-level local seismic response.

Local Seismic Response RSL III – Software for the evaluation of third-level local seismic response.

Using the third-level method, it is possible to accurately assess the actual stratigraphic amplification by solving the differential equation governing the propagation of shear waves in a Kelvin–Voigt viscoelastic medium, with soil behavior defined by degradation curves for shear modulus (G) and damping derived from scientific literature and/or Italian standards, as well as user-defined curves.

The calculation procedure adopted by RSL III for local seismic response is based on an equivalent linear approach applied to a model consisting of n horizontal, parallel layers of infinite lateral extent over a half-space representing the bedrock.

The seismic input, represented by one or more accelerograms, is applied at the bedrock, and the propagation of waves in the direction perpendicular to the ground surface is evaluated using the dynamic equilibrium equation expressed in terms of displacement.

The final results provided by the third-level analysis include accelerograms and their corresponding response spectra, as well as the mean spectrum and the normalized mean spectrum to be compared with the reference spectrum defined by Italian standards.