Preliminary empirical scaling of pseudo relative velocity spectra in Serbia from the Vrancea earthquakes

Soil Dynamics and Earthquake Engineering

Bulajić

et al. 2017

Self Cite

Keywords:Microzonation maps, which include descriptions of site geology and site soil properties Contribution of a large distant earthquake to the design strong motion amplitudes Computation of seismic hazard for earthquake sources, which follow different attenuation laws A B S T R A C T 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.

Section: Contribution Of the Vrancea Earthquakes To Seismic Hazardmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Seismic microzoning in Skopje, Macedonia

Soil Dynamics and Earthquake Engineering

Bulajić

et al. 2017

Self Cite

“…3). This results in attenuation of high-frequency spectral amplitudes [36,37] so that the UHS for peak accelerations in Štip (Fig. 4), for a typical range of exceedance probabilities, are dominated only by local seismicity.…”

Section: Vrancea Earthquake Contributions To Seismic Hazardmentioning

confidence: 99%

“…Throughout this paper, we have used empirical scaling equations in all calculations that were developed from strong motion data recorded in the former Yugoslavia [28,29,37]. As this data had only a few recordings on deep soil sites (S L =2, [59,61]), our empirical scaling equations for PSV amplitudes do not include the scaling in terms of S L =2.…”

Section: Vw Lee Et Almentioning

confidence: 99%

“…The methodology, scaling equations, and descriptions of seismicity used are the same as those described by Lee et al [33][34][35][36][37], and Lee and Trifunac [31,32] and will not be repeated here. Useful features in this work include (1) that the detailed spatial variations of the geologic site conditions can be integrated directly into the calculation of spectral amplitudes, and as will be shown, are one of the significant factors influencing the final result; and (2) that the consequences of contributions from large distant earthquakes (from Vrancea in Romania) can also be included.…”

Section: Introductionmentioning

confidence: 99%

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Seismic microzoning of Štip in Macedonia

Soil Dynamics and Earthquake Engineering

Bulajić

et al. 2017

Self Cite

Keywords:Microzonation maps, which include descriptions of site geology and site soil properties Contribution of a large distant earthquake to the design strong motion amplitudes Computation of seismic hazard for earthquake sources, which follow different attenuation laws A B S T R A C T Seismic microzonation maps for Štip (Macedonia) and its surroundings are presented based on the uniformhazard-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 microzoning of the Delhi metropolitan area, India—II: Hazard computation and zoning maps

Gupta

Earthquake Engineering and Resilience

2022

We present seismic microzonation maps of New Delhi, India, using the probabilistic seismic hazard analysis (PSHA) method with input seismic activity parameters estimated in Part-I of this two-part paper. Our calculations required three different attenuation equations for amplitude scaling of strong ground motion from three principal contributing sources: the National Capital Region (NCR), Northwestern Himalaya (NWH), and the Hindu Kush subduction (HKS). We show that uniform hazard spectral (UHS) amplitudes are dominated only by the local seismicity in the NCR at high frequencies beyond about 2 Hz. For intermediate and long periods, UHS amplitudes are dominated by contributions from the NWH and HKS earthquakes. Our results show that specifying strong motion amplitudes for use in engineering design by means of peak ground acceleration can lead to serious errors for buildings higher than four to five stories and hence should not be used. Our results also show that the shape of design spectra must depend on the nature of contributing earthquake sources, their relative activity, potential to create large magnitudes, and geographical placement relative to the site of interest, and thus a standard design-spectrum shape cannot satisfy all these requirements. We use local geological site condition parameters directly in all calculations and present hazard maps for three different soil site conditions ("rock," stiff soil sites, and deep soil sites). Thus, the user can extract the UHS amplitudes of pseudo relative velocity spectra at any site in the National Capital Territory by experimentally determining the local soil site conditions and then applying the corresponding maps shown in this paper. K E Y W O R D Scontribution from a large distant earthquake to the design strong motion amplitudes; computation of seismic hazard for earthquake sources, which follow different attenuation laws; microzonation maps that include a description of site geology and site soil properties