Free software for earthquake engineering and structural dynamic

(the software may be free downloaded and used at own risk)

Sabetta is an OCTAVE code for the generation of synthetic earthquakes with a non-stationary simulation according to the model of Sabetta and Pugliese.
By contrast to the stationary simulation of SimSeisme, Sabetta does not lead to synthetic earthquakes compatible to a design spectrum. However the simulation is much closer to recorded earthquakes and provides more reliable seismic structural response, more specifically by non-linear structural behaviour. The three input parameters (magnitude, epicentral distance and soil conditions) may be adjusted to approach a design spectrum for the mean values of several generated synthetic earthquakes.


To run Sabetta.m:

  • Run Octave
  • Type Sabetta and Return
  • Answer the questions concerning magnitude, epicentral distance and soil conditions

Informations and recommendations

  • Sabetta is based on the work of Sabetta and Pugliese. More informations may be found in their publication:

    Sabetta F., Pugliese A.: Estimation of Response Spectra and Simulation of Nonstationary Earthquake Ground Motions.
    Bulletin of the Seismological Society of America, Vol. 86, No. 2, pp. 337-352, April 1996.


  • Patience, the generation of an accelerogram takes several minutes! The calculating time may be shortened by the modification (300 or less instead of 400) of the considered frequencies in the generation (near the end of Sabetta.m):

    for N=1:400,
    f=N/(T4/3.0); …


  • Since in the model the phase angle content is randomly distributed, it is recommended to change the seed value of the random generator
    before each start: rand(“seed”,sum(871*clock)), i. e. change the actual value of 871 by any other value.