Page - 1102 - in Book of Full Papers - Symposium Hydro Engineering

Fig. 2 Location of earthquake epicenters within a radius of 300 km around the site The estimation of the maximum magnitude (Mmax) and recurrence relationships was performed using by both of the classical approach of Gutenberg & Richter [1] and of the Kijko-Sellevoll method [2]. The advantages of using both of these methods are containing the largest earthquakes and containing data sets which are complete from different thresholds of magnitude upwards. The method can also consider gaps when records in the catalogue are missing and uncertainties in earthquake magnitudes. 3.2. ATTENUATION RELATIONSHIPS Seismic loads imposed on a dam structure such as power plant by ground motions are usually expressed as peak values of ground acceleration, velocity, and displacement. The peak ground acceleration (PGA) is often used to quantify the seismic hazard for a structure. The values of ground motion parameters (Y) at a site (Include PGA) are estimated by so-called attenuation laws which in their simplest form are expressed as "Eq. [1] ". logY = logf1 (magnitude) + logf2 (distance)+..+ ε [1] Attenuation of ground motion depends on many factors such as the fault mechanism, site geological conditions, thickness and type of overburden, etc. The most recent attenuation laws have also taken into account these effects. For 1102