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 earthquake...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.展开更多
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’...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.展开更多
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 ...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.展开更多
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 a...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.展开更多
The fifth-generation seismic hazard map for China's mainland(CSHM5) was developed based on the delineated seismic source models and the ground motion models(GMMs) for the peak ground acceleration(PGA) for four dif...The fifth-generation seismic hazard map for China's mainland(CSHM5) was developed based on the delineated seismic source models and the ground motion models(GMMs) for the peak ground acceleration(PGA) for four different seismic regions. In the present study, we developed a new set of GMMs as functions of the rupture distance or the closest distance to the projection of the rupture plane. The development of the GMMs is based on the projection method and GMMs from the NGA-West2 project. We then estimated, mapped, and compared the seismic hazard in terms of PGA and pseudo-spectral acceleration by using the new set of GMMs and other relevant GMMs, and two seismic source models-one used in developing CSHM5, which includes the fault orientation characterization and the other based on a spatially smoothed source model. The comparison of the estimated seismic hazard indicates that CSHM5 may significantly underestimate the seismic hazard. Part of this is likely due to the inclusion of an additional 15 km focal depth in the original GMM that is adopted for CSHM5. The comparison of the obtained standardized uniform hazard spectra(UHS) to the standardized response spectrum implemented in the current structural design code shows that the value of the latter is greater than that of the former for the natural vibration period less than about 0.1 s or greater than 0.4 s and this is reversed for the natural vibration period around 0.2 s. It is recommended that the use of UHS for design code making should be seriously considered, or at least, the shape of the current implemented standardized design spectrum could be improved.展开更多
文摘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.
基金supported by the Shota Rustaveli National Science Foundation of Georgia(SRNSFG)(No.FR-19-3657)。
文摘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.
基金supported by the Mandatory Research Fund from the University of Bengkulu,with Grant No.3968/UN30.15/LT/2018
文摘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.
文摘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.
基金supported by the Fundamental Research Funds for the Central Universities,CHD(Grant No.300102282103)Natural Science Basic Research Program of Shaanxi(Program No.2023-JC-QN-0512)(CF)+1 种基金the National Key R&D Program of China(Grant No.2023YFC3805202)(HPH)the Institute of Geophysics,China Earthquake Administration(WJX)is gratefully acknowledged.
文摘The fifth-generation seismic hazard map for China's mainland(CSHM5) was developed based on the delineated seismic source models and the ground motion models(GMMs) for the peak ground acceleration(PGA) for four different seismic regions. In the present study, we developed a new set of GMMs as functions of the rupture distance or the closest distance to the projection of the rupture plane. The development of the GMMs is based on the projection method and GMMs from the NGA-West2 project. We then estimated, mapped, and compared the seismic hazard in terms of PGA and pseudo-spectral acceleration by using the new set of GMMs and other relevant GMMs, and two seismic source models-one used in developing CSHM5, which includes the fault orientation characterization and the other based on a spatially smoothed source model. The comparison of the estimated seismic hazard indicates that CSHM5 may significantly underestimate the seismic hazard. Part of this is likely due to the inclusion of an additional 15 km focal depth in the original GMM that is adopted for CSHM5. The comparison of the obtained standardized uniform hazard spectra(UHS) to the standardized response spectrum implemented in the current structural design code shows that the value of the latter is greater than that of the former for the natural vibration period less than about 0.1 s or greater than 0.4 s and this is reversed for the natural vibration period around 0.2 s. It is recommended that the use of UHS for design code making should be seriously considered, or at least, the shape of the current implemented standardized design spectrum could be improved.
