Seismic microzonation maps for Belgrade (Serbia) and its surroundings are presented based on the uniform hazard -spectrum (UHS) methodology. Such mapping must satisfy the guidelines for performance-based design (PBD), which at present requires the specification of two sets of spectral amplitudes, one in which the structure would remain essentially linear, and one in which it would undergo nonlinear response. These requirements cannot be achieved by specifying the design spectra using only one (same) fixed spectral shape, and such spectra cannot be scaled by the peak ground acceleration alone. Another source of difficulties in the selection of the design amplitudes for PBD occurs when the standard spectrum shape is not capable of describing excitation by large, distant earthquakes. Furthermore, scaling the site dependent design ground motion only via soil site classification ignores the' effects of site geology and thus leads to biased results. The maps we present in this paper avoid these shortcomings and include the effects of near and distant large earthquakes, spatial distribution of seismic activity, site geology, and site soil properties in a balanced way.

Seismic microzonation maps for Štip (Macedonia) and its surroundings are presented based on the uniform-hazard-spectrum (UHS) methodology. Such mapping satisfies the guidelines for performance-based design (PBD), which requires specification of two sets of spectral amplitudes—one for which the structure will remain essentially linear, and the other for which it will undergo a nonlinear response. The UHS method also enables us to include contributions from excitation by large distant earthquakes as well as the simultaneous effects of site geology and site soils. Thus, the maps we present include, in a balanced way, the effects of near and distant large earthquakes, spatial distribution of seismic activity, the site geology, and the site soil properties.

Seismic microzonation maps for Skopje (Macedonia) are presented based on the Uniform-Hazard-Spectrum (UHS) methodology. UHS satisfies the guidelines for performance-based design (PBD), which require specification of two sets of spectral amplitudes, one for which the structure will remain essentially linear, and the other for which it will undergo a nonlinear response. The UHS method also considers the contributions from large distant earthquakes and includes simultaneous effects of site geology and site soils. The maps presented include the effects of near and distant large earthquakes in a balanced way, spatial distribution of seismic activity, site geology, and site soil properties.

We present the frequency-dependent attenuation model for Fourier amplitude spectra of strong earthquake ground motion in Serbia from intermediate depth earthquakes in the Vrancea source zone in Romania. The development of this type of scaling is the essential first step toward developing the corresponding attenuation and scaling equations for pseudo relative velocity spectra (PSV), which are necessary for seismic macro- and microzoning in the territory of Serbia. Such scaling is necessary because the Vrancea source zone produces large earthquakes with shaking that attenuates differently from the local earthquakes in Serbia. Development of such a scaling model is associated with several difficulties, the principal one being the lack of recorded strong motion accelerograms at epicentral distances exceeding 300km. To reduce uncertainties with such scaling, we require our preliminary scaling equations to be consistent with independent estimates of seismic moment, stress drop, and radiated wave energy. In the future, when the recorded strong motion data from Vrancea earthquakes increases several-fold of what it is today, it will become possible to perform this analysis again, thus leading to more reliable and permanent scaling estimates.

First frequency-dependent empirical scaling equations of pseudo-relative velocity spectral amplitudes (PSV) of strong earthquake ground motions in the former Yugoslavia were introduced in the mid-1990s by Lee and Trifunac (1990) [15]. This followed the development of the Fourier spectral amplitudes (FS) scaling equations by Lee and Trifunac (1993) [17] in terms of earthquake source parameters, and the region-specific frequency dependent attenuation function given by Lee and Trifunac (1992) [16]. More recently, a new frequency-dependent attenuation function was developed for central and eastern Serbia for earthquakes of intermediate and large magnitudes and for large epicentral distances-exceeding 300 km-suggested by Lee et al. (2016) [19] that occur in the Vrancea source region in Romania. In this paper we use this frequency-dependent attenuation function to develop empirical scaling equations for PSV spectral amplitudes in Serbia. These scaling equations will form a basis for macro- and micro-zoning earthquake hazard studies in Serbia. (C) 2016 Elsevier Ltd. All rights reserved.

Peak ground accelerations, computed from sliding of objects during the 1969 Banja Luka earthquakes in Bosnia and Herzegovina (former Yugoslavia) are computed assuming that the ground motion consists of simple rectangular or sinusoidal pulses. The results show good agreement with observed macroseismic estimates of shaking based on the Mercalli–Cancani–Sieberg (MCS) intensity scale. The results are also in compliance with recorded accelerations during the 1973–1986 period and with recent probabilistic hazard analyses for the Banja Luka region.

New microzonation maps for the city of Banja Luka in the Republic of Srpska in Bosnia and Herzegovina are presented based on the uniform-hazard-spectrum (UHS) methodology. The results are compared with the previous generation of microzonation maps published in the early 1970s, which were determined for the largest expected levels of shaking and for the spatial variations based on the soil site properties and the observed damage during the 1969 earthquake. The old and new methods are compared with emphasis on their role in the long-term criteria for regional earthquake-resistant design guidelines and the associated consequences.