As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment...As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment) procedure to the large amount of available geological, geophysical and tectonic Kazakh data and to meet standard requirements for the Eurocode 8. The new procedure has been used within National projects to develop the Probabilistic GSZ(General Seismic Zoning) maps of the Kazakhstan territory and the SMZ(Probabilistic Seismic Microzoning) maps of Almaty city. They agree with the seismic design principles of Eurocode 8 and are expressed in terms of not only seismic intensity,but also engineering parameters(peak ground acceleration PGA). The whole packet of maps has been developed by the Institute of Seismology, together with other Kazakhstan Institutions. Our group was responsible for making analysis in PGA. The GSZ maps and hazard assessment maps for SMZ in terms of PGA for return periods 475 and 2475 years are considered in the article.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 estimated seismic hazard based on the delineated seismic source model is used as the basis to assign the seismic design loads in Canadian structural design codes.An alternative for the estimation is based on a spa...The estimated seismic hazard based on the delineated seismic source model is used as the basis to assign the seismic design loads in Canadian structural design codes.An alternative for the estimation is based on a spatially smoothed source model.However,a quantification of differences in the Canadian seismic hazard maps(CanSHMs)obtained based on the delineated seismic source model and spatially smoothed model is unavailable.The quantification is valuable to identify epistemic uncertainty in the estimated seismic hazard and the degree of uncertainty in the CanSHMs.In the present study,we developed seismic source models using spatial smoothing and historical earthquake catalogue.We quantified the differences in the estimated Canadian seismic hazard by considering the delineated source model and spatially smoothed source models.For the development of the spatially smoothed seismic source models,we considered spatial kernel smoothing techniques with or without adaptive bandwidth.The results indicate that the use of the delineated seismic source model could lead to under or over-estimation of the seismic hazard as compared to those estimated based on spatially smoothed seismic source models.This suggests that an epistemic uncertainty caused by the seismic source models should be considered to map the seismic hazard.展开更多
On August 20th,2019,a M4.2 earthquake occurred near Zhanan and Lixin Village,Tianya District,Sanya City,Hainan Province. We conduct field investigations in the vicinity of the epicenter which includes 25 natural villa...On August 20th,2019,a M4.2 earthquake occurred near Zhanan and Lixin Village,Tianya District,Sanya City,Hainan Province. We conduct field investigations in the vicinity of the epicenter which includes 25 natural villages based on the data provided by local government and finally complete the map of the earthquake intensity.Through the analysis of the houses and cracks in the earthquake area,the structure types and crack characteristics of the houses are basically unveiled. Furthermore,suggestions for earthquake disaster reduction in study area are obtained from the investigation.展开更多
This study focuses on rapidly determining seismic intensity maps of earthquakes because it offers fundamental information for effective emergency rescue and subsequent scientific research,and remains challenging to ac...This study focuses on rapidly determining seismic intensity maps of earthquakes because it offers fundamental information for effective emergency rescue and subsequent scientific research,and remains challenging to accurately determine seismic intensity map in regions with sparse instrumental observations.Here we applied a novel method that consisted of array technology(backprojection),ground-motion prediction equations,and site corrections,to estimate the seismic intensity maps of the 2021 Mw 7.3 Madoi,Qinghai and the Mw 6.1 Yangbi,Yunnan,China earthquakes.We used seismic data recorded at European stations to back-project the source processes of the 2021 Mw7.3 Madoi,Qinghai and the Mw 6.1 Yangbi,Yunnan,China earthquakes.The back-projected energy radiations were then used as subevents or used to define the fault geometry.Summing the contributions of each subevent or estimating the shortest distances from each site to the rupture fault,we obtained the ground motion(PGA and PGV)for each site under rock site conditions.The estimated ground motions were corrected at each site for local site amplification according to the Vs30 database.Our estimated seismic intensity maps and field reports showed high similarity,which further validated the effectiveness of the novel approach,and pushed the limit of earthquake size down to~M 6.Such efforts would substantially help in the fast and accurate evaluation of earthquake damage,and precise rescue efforts.展开更多
基金"Development of the Map of General Seismic Zoning in the Territory of the Republic of Kazakhstan" (state registration 0113RK01142)"Development of the map of Seismic Microzoning of the Territory of Almaty City"(state registration 0115RK02701)funded within the state funding
文摘As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment) procedure to the large amount of available geological, geophysical and tectonic Kazakh data and to meet standard requirements for the Eurocode 8. The new procedure has been used within National projects to develop the Probabilistic GSZ(General Seismic Zoning) maps of the Kazakhstan territory and the SMZ(Probabilistic Seismic Microzoning) maps of Almaty city. They agree with the seismic design principles of Eurocode 8 and are expressed in terms of not only seismic intensity,but also engineering parameters(peak ground acceleration PGA). The whole packet of maps has been developed by the Institute of Seismology, together with other Kazakhstan Institutions. Our group was responsible for making analysis in PGA. The GSZ maps and hazard assessment maps for SMZ in terms of PGA for return periods 475 and 2475 years are considered in the article.
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.
基金The support of the Fundamental Research Funds from the Central Universities,CHD(Grant No.300102282103)Natural Science Basic Research Program of Shaanxi(Program No.2023-JC-QN-0512)Harbin Institute of Technology(Shenzhen)。
文摘The estimated seismic hazard based on the delineated seismic source model is used as the basis to assign the seismic design loads in Canadian structural design codes.An alternative for the estimation is based on a spatially smoothed source model.However,a quantification of differences in the Canadian seismic hazard maps(CanSHMs)obtained based on the delineated seismic source model and spatially smoothed model is unavailable.The quantification is valuable to identify epistemic uncertainty in the estimated seismic hazard and the degree of uncertainty in the CanSHMs.In the present study,we developed seismic source models using spatial smoothing and historical earthquake catalogue.We quantified the differences in the estimated Canadian seismic hazard by considering the delineated source model and spatially smoothed source models.For the development of the spatially smoothed seismic source models,we considered spatial kernel smoothing techniques with or without adaptive bandwidth.The results indicate that the use of the delineated seismic source model could lead to under or over-estimation of the seismic hazard as compared to those estimated based on spatially smoothed seismic source models.This suggests that an epistemic uncertainty caused by the seismic source models should be considered to map the seismic hazard.
基金sponsored by the Disaster Risk Prevention Technology Innovation Team Fund of Hainan Earthquake Agency&Research Project of Hainan Earthquake Agency(HDKJ201904)。
文摘On August 20th,2019,a M4.2 earthquake occurred near Zhanan and Lixin Village,Tianya District,Sanya City,Hainan Province. We conduct field investigations in the vicinity of the epicenter which includes 25 natural villages based on the data provided by local government and finally complete the map of the earthquake intensity.Through the analysis of the houses and cracks in the earthquake area,the structure types and crack characteristics of the houses are basically unveiled. Furthermore,suggestions for earthquake disaster reduction in study area are obtained from the investigation.
基金supported by the Fundamental Research Funds in the Institute of Earthquake Science,China Earthquake Administration(No.2020IESLZ05)the National Key R&D Program of the Republic of China(Nos.2017YFC1500906 and 2018YFC0603500)the National Natural Science Foundation of China(Nos.41922025 and41874062)。
文摘This study focuses on rapidly determining seismic intensity maps of earthquakes because it offers fundamental information for effective emergency rescue and subsequent scientific research,and remains challenging to accurately determine seismic intensity map in regions with sparse instrumental observations.Here we applied a novel method that consisted of array technology(backprojection),ground-motion prediction equations,and site corrections,to estimate the seismic intensity maps of the 2021 Mw 7.3 Madoi,Qinghai and the Mw 6.1 Yangbi,Yunnan,China earthquakes.We used seismic data recorded at European stations to back-project the source processes of the 2021 Mw7.3 Madoi,Qinghai and the Mw 6.1 Yangbi,Yunnan,China earthquakes.The back-projected energy radiations were then used as subevents or used to define the fault geometry.Summing the contributions of each subevent or estimating the shortest distances from each site to the rupture fault,we obtained the ground motion(PGA and PGV)for each site under rock site conditions.The estimated ground motions were corrected at each site for local site amplification according to the Vs30 database.Our estimated seismic intensity maps and field reports showed high similarity,which further validated the effectiveness of the novel approach,and pushed the limit of earthquake size down to~M 6.Such efforts would substantially help in the fast and accurate evaluation of earthquake damage,and precise rescue efforts.