This paper introduced domestic and overseas status, the historical evolution and the development history of earthquake disaster reduction planning. The urgencies and realistic significance were analyzed to carry out e...This paper introduced domestic and overseas status, the historical evolution and the development history of earthquake disaster reduction planning. The urgencies and realistic significance were analyzed to carry out earthquake disaster reduction planning for districts or countries in the northwest. With Hongsibao District in Wuzhong City, Ningxia Province as an example, this article analyzed in detail the present situation and the special problems of earthquake disaster reduction planning in Northwest China. The relevant solving measures were put forward in order to offer a reference for the scientific establishment and effective implementation of earth- quake disaster reduction planning in Northwest China. The foundation of earthquake disaster reduction in the Hongsibao District is still very weak, there is a single earthquake monitoring means, the emergency rescue system is not complete, the working mechanism is not perfect, and the lack of funding for the work of earthquake disaster reduction.展开更多
The Anninghe fault is a major left-lateral strike-slip fault in southwest China and a seismic gap with a potential earthquake larger than MW 7.0 lies in the Mianning-Xichang segment according to recent observations.Th...The Anninghe fault is a major left-lateral strike-slip fault in southwest China and a seismic gap with a potential earthquake larger than MW 7.0 lies in the Mianning-Xichang segment according to recent observations.The shallow structure of this region can offer a glimpse into the geometry of the fault,which plays an important role in earthquake hazard mitigation.To further investigate the sedimentary structure of the Anninghe fault zone,two dense linear arrays with a station spacing of around 80 m were deployed across the fault.In this study,the H/V spectral ratio(HVSR),together with its peak frequency at each station site,was obtained by applying the Nakamura method.Our findings demonstrate that the peak frequency behaves in high correlation with lithology and is controlled by topography.HVSR in foothills or regions with magmatic intrusion shows a single peak at about 2–3 Hz.In locations with abundant Quaternary sedimentation,such as Anninghe valleys and fracture zones,another low-frequency peak around 0.4 Hz can be noticed in HVSR.By using the empirical relationship,the thickness of the sedimentary layer around the fault fracture zone is estimated to be 300–600 m.Furthermore,the sedimentary interface shows a downward dip to the east,possibly influenced by the east-west extrusion stress.Considering the resonance effect,buildings with 6–9 stories in the valley area of the Anninghe require additional attention in earthquake hazard prevention.展开更多
Based on the available and supplementary survey data,it analyzes the effect of seismicity in Taiwan and the Taiwan Straits on the southeastern coastal area of the Chinese mainland and discusses its roles in seismic ha...Based on the available and supplementary survey data,it analyzes the effect of seismicity in Taiwan and the Taiwan Straits on the southeastern coastal area of the Chinese mainland and discusses its roles in seismic hazard prevention and textual research of historical earthquakes. The results show that the frequency of strong earthquake in Taiwan Region is high,with a time interval ranging from several to dozens of years,but the maximum influence intensity of seismicity from there to the coastal areas of the Chinese mainland is only VI degree; while the maximum influence intensity of the seismicity along the littoral fault zone located on the west of the straits reaches VIII ~ IX degree because of the shorter distance to the Chinese mainland,though the frequency of strong earthquakes is lower than that of the Taiwan Region. Strategies for protecting against seismic hazards in the southeastern coastal area of China are proposed. Besides focusing on the effect of strong earthquakes of the littoral fault zone,attention also has to be paid to the low-cycle fatigue failure of engineering structures induced by the earthquakes in Taiwan and the stir effect on society induced by earthquake phobia. It is concluded that it would be more accurate and proper to take the May 19,1517 earthquake recorded in the Chinese mainland area as the influence of a strong earthquake in the Taiwan Region.展开更多
Topography can strongly affect ground motion,and studies of the quantification of hill surfaces’topographic effect are relatively rare.In this paper,a new quantitative seismic topographic effect prediction method bas...Topography can strongly affect ground motion,and studies of the quantification of hill surfaces’topographic effect are relatively rare.In this paper,a new quantitative seismic topographic effect prediction method based upon the BP neural network algorithm and three-dimensional finite element method(FEM)was developed.The FEM simulation results were compared with seismic records and the results show that the PGA and response spectra have a tendency to increase with increasing elevation,but the correlation between PGA amplification factors and slope is not obvious for low hills.New BP neural network models were established for the prediction of amplification factors of PGA and response spectra.Two kinds of input variables’combinations which are convenient to achieve are proposed in this paper for the prediction of amplification factors of PGA and response spectra,respectively.The absolute values of prediction errors can be mostly within 0.1 for PGA amplification factors,and they can be mostly within 0.2 for response spectra’s amplification factors.One input variables’combination can achieve better prediction performance while the other one has better expandability of the predictive region.Particularly,the BP models only employ one hidden layer with about a hundred nodes,which makes it efficient for training.展开更多
基金Supported by State Key Laboratory of Loess and Quaternary Geology Open-end Fund(SKLLQG1426)Post-doctoral Foundation and National Natural Science Foundation of China(41102107)~~
文摘This paper introduced domestic and overseas status, the historical evolution and the development history of earthquake disaster reduction planning. The urgencies and realistic significance were analyzed to carry out earthquake disaster reduction planning for districts or countries in the northwest. With Hongsibao District in Wuzhong City, Ningxia Province as an example, this article analyzed in detail the present situation and the special problems of earthquake disaster reduction planning in Northwest China. The relevant solving measures were put forward in order to offer a reference for the scientific establishment and effective implementation of earth- quake disaster reduction planning in Northwest China. The foundation of earthquake disaster reduction in the Hongsibao District is still very weak, there is a single earthquake monitoring means, the emergency rescue system is not complete, the working mechanism is not perfect, and the lack of funding for the work of earthquake disaster reduction.
基金This study was jointly supported by the Key Research and Development Program of China(2021YFC3000704,2018YFC1503400)the National Natural Science Foundation of China(42125401)the special fund of Key Laboratory of Earthquake Prediction,CEA(2021IEF0103).
文摘The Anninghe fault is a major left-lateral strike-slip fault in southwest China and a seismic gap with a potential earthquake larger than MW 7.0 lies in the Mianning-Xichang segment according to recent observations.The shallow structure of this region can offer a glimpse into the geometry of the fault,which plays an important role in earthquake hazard mitigation.To further investigate the sedimentary structure of the Anninghe fault zone,two dense linear arrays with a station spacing of around 80 m were deployed across the fault.In this study,the H/V spectral ratio(HVSR),together with its peak frequency at each station site,was obtained by applying the Nakamura method.Our findings demonstrate that the peak frequency behaves in high correlation with lithology and is controlled by topography.HVSR in foothills or regions with magmatic intrusion shows a single peak at about 2–3 Hz.In locations with abundant Quaternary sedimentation,such as Anninghe valleys and fracture zones,another low-frequency peak around 0.4 Hz can be noticed in HVSR.By using the empirical relationship,the thickness of the sedimentary layer around the fault fracture zone is estimated to be 300–600 m.Furthermore,the sedimentary interface shows a downward dip to the east,possibly influenced by the east-west extrusion stress.Considering the resonance effect,buildings with 6–9 stories in the valley area of the Anninghe require additional attention in earthquake hazard prevention.
基金sponsored by the Special Project of Seismic Industry,Study on the Seismic Safety of Nuclear Power Plant (200708003)
文摘Based on the available and supplementary survey data,it analyzes the effect of seismicity in Taiwan and the Taiwan Straits on the southeastern coastal area of the Chinese mainland and discusses its roles in seismic hazard prevention and textual research of historical earthquakes. The results show that the frequency of strong earthquake in Taiwan Region is high,with a time interval ranging from several to dozens of years,but the maximum influence intensity of seismicity from there to the coastal areas of the Chinese mainland is only VI degree; while the maximum influence intensity of the seismicity along the littoral fault zone located on the west of the straits reaches VIII ~ IX degree because of the shorter distance to the Chinese mainland,though the frequency of strong earthquakes is lower than that of the Taiwan Region. Strategies for protecting against seismic hazards in the southeastern coastal area of China are proposed. Besides focusing on the effect of strong earthquakes of the littoral fault zone,attention also has to be paid to the low-cycle fatigue failure of engineering structures induced by the earthquakes in Taiwan and the stir effect on society induced by earthquake phobia. It is concluded that it would be more accurate and proper to take the May 19,1517 earthquake recorded in the Chinese mainland area as the influence of a strong earthquake in the Taiwan Region.
基金supported by the National Natural Science Foundation of China(No.51878625)the Collaboratory for the Study of Earthquake Predictability in China Seismic Experimental Site(No.2018YFE0109700)the General Scientific Research Foundation of Shandong Earthquake Agency(No.YB2208).
文摘Topography can strongly affect ground motion,and studies of the quantification of hill surfaces’topographic effect are relatively rare.In this paper,a new quantitative seismic topographic effect prediction method based upon the BP neural network algorithm and three-dimensional finite element method(FEM)was developed.The FEM simulation results were compared with seismic records and the results show that the PGA and response spectra have a tendency to increase with increasing elevation,but the correlation between PGA amplification factors and slope is not obvious for low hills.New BP neural network models were established for the prediction of amplification factors of PGA and response spectra.Two kinds of input variables’combinations which are convenient to achieve are proposed in this paper for the prediction of amplification factors of PGA and response spectra,respectively.The absolute values of prediction errors can be mostly within 0.1 for PGA amplification factors,and they can be mostly within 0.2 for response spectra’s amplification factors.One input variables’combination can achieve better prediction performance while the other one has better expandability of the predictive region.Particularly,the BP models only employ one hidden layer with about a hundred nodes,which makes it efficient for training.