Spectral-based Probabilistic Seismic Hazard Analysis for Fethiye,Mugla

Fethiye is an important region located in the eastern part of the Mediterranean Basin.This region which is the most active part of the south-western Anatolia extensional tectonic regime,has been effected by earthquakes,submarine landslides and tsunamis throughout the history due to the existence of the complex active plate boundary zone.The active area has been exposed to ground motion that had the potential to damage vulnerable structures.Therefore,a detailed assessment of seismic hazard is necessary for the prevention of potential damage.In this context,probabilistic seismic hazard analysis is performed by R-CRISIS-18.3 using the refined parameters computed from Seismic Hazard Harmonization for Europe(SHARE)project.Spatial distribution of spectral acceleration at T=0.2 s and T=1.0 s for the earthquake levels that corresponds to the average return period of 72,475 and 2475 years is calculated.Hazard curves for the central region of Fethiye district are generated.The results are discussed and compared with the values obtained from the Revision of Turkish Seismic Hazard Map Project(UDAP-C-13-06).These local results of probabilistic seismic hazard analysis will provide the basis for the preparation of seismic risk maps as future work.

Local seismic hazard map based on the response spectra of stiff and very dense soils in Bengkulu city,Indonesia

It is well known that seismic hazard assessment should be implemented to design infrastructures in an earthquake-prone area such as Bengkulu.This paper presents local seismic hazard maps based on the response spectra of stiff and very dense soils in Bengkulu city,Indonesia.We collect the soil data and conduct the seismic wave propagation.The input motion for wave propagation analysis is generated from the spectral acceleration curves of stiff and dense soils.Various ground motion parameters such as peak ground acceleration,short-period and long-period spectral accelerations,and amplification factors are presented in microzonation maps.The results show that the peak ground acceleration in the study area ranges from 0.2 to 0.8 g,while the spectral acceleration varies between 0.5-1.5 g and 0.4-0.8 g for periods of 0.2 and 1 s,respectively.The amplification factor of the site is observed to vary from 0.5 to 1.6.Considering other spectral accelerations in Bengkulu,the spectral acceleration design shows a good performance.The results indicate the site characteristics of Bengkulu city,which can provide engineers with site class for structural building design.

Ground motion prediction equations based on shallow crustal earthquakes in Georgia and the surrounding Caucasus

Strong ground motions caused by earthquakes with magnitudes ranging from 3.5 to 6.9 and hypocentral distances of up to 300km were recorded by local broadband stations and three-component accelerograms within Georgia’s enhanced digital seismic network.Such data mixing is particularly effective in areas where strong ground motion data are lacking.The data were used to produce models based on ground-motion prediction equations(GMPEs),one benefit of which is that they take into consideration information from waveforms across a wide range of frequencies.In this study,models were developed to predict ground motions for peak ground acceleration and 5%-damped pseudo-absolute-acceleration spectra for periods between 0.01 and 10 s.Short-period ground motions decayed faster than long-period motions,though decay was still in the order of approximately 1/r.Faulting mechanisms and local soil conditions greatly influence GMPEs.The spectral acceleration(SA)of thrust faults was higher than that for either strike-slip or normal faults but the influence of strike-slip faulting on SA was slightly greater than that for normal faults.Soft soils also caused significantly more amplification than rocky sites.

Elastic and Inelastic Response of Structural Systems in Seismic Pounding

The present paper addresses the comparative study of three adjacent single-degree-of freedom structures for elastic and inelastic system with and without pounding under seismic excitations. For the gap between three adjacent structures, the simulation is done by using linear spring element without damping. The entire numerical simulation is done in time domain by considering the inputs of four real ground motions. The results of the study show that the response of elastic system is much different to that of response of inelastic system in the absence and presence of pounding, especially in lighter or more flexible structures. Elastic structures show much severe pounding response than inelastic structures. Modeling of colliding structures behaving inelastically is really needed in order to obtain the accurate structural pounding involved response under seismic excitation.