LOCAL EARTHQUAKES - GROUND MOTION MODELS FOR EPICENTRAL ZONE

Ground motion models - GMM-s for epicentral zone have been developed based on records of occurred shallow earthquakes obtained on soil type - rock, epicentral distances ., focal depths and local magnitude M = 3.9 - 6.1. Spectral acceleration - SA has been investigated for damping of 5% and for 221 models of a single-degree-of-freedom system with natural period ranging from 0.05 to 5.0 seconds. Two mathematical physical models have been selected. In the first one, the spectral acceleration - SA depends on magnitude only, while in the second one, it depends on magnitude and hypocentral distance. For an assumed normal distribution for the natural logarithm of SA, a multi-linear regression analysis has been carried out. The results have been regression coefficients and standard deviations. These are practically applicable for prediction of expected SA in an epicentral zone in deterministic and probabilistic methods. Key words: ground motion model, spectral acceleration, epicentral zone, magnitude, epicentral distance.