For earthquake-prone countries of the world, it is crucial to develop countermeasures and to share experiences in seismic hazard mitigation. The measures for seismic hazard mitigation are related to many factors, e.g....For earthquake-prone countries of the world, it is crucial to develop countermeasures and to share experiences in seismic hazard mitigation. The measures for seismic hazard mitigation are related to many factors, e.g., social, economic, and political. Research focused on modern science and technology paves the way for a better understanding of the earthquake phenomenon and helps to plan against its effects in seismically active areas.In this paper, we consider some of the events that occurred in earthquake-prone countries, both developing and developed, which caused devastation to the society and economy. These are mainly major events that have affected a considerable portion of the gross domestic product of these economies.Measures to mitigate seismic hazard are stressed and suggested. In addition, experiences in seismic hazard mitigation in Uganda and the rest of the world are discussed in general terms. Attention is given to geotectonic settings as well as the work of seismic hazard and disaster展开更多
Analysis of seismic data and seismicity characteristics in China, we gave a method to deal with seismic patterns by calculating density at grid nodes. Number of earthquakes and epicenter distribution are considered co...Analysis of seismic data and seismicity characteristics in China, we gave a method to deal with seismic patterns by calculating density at grid nodes. Number of earthquakes and epicenter distribution are considered comprehensively in this method. Effect of datum accuracy is stressed on parameter confirmation. Seismic patterns from this method are stable and can reflect seismic characteristics reliably. These seismic patterns are the base of quantitative analysis of seismicity. It can be applied in seismic tendency analysis and medium-long term earthquake prediction, earthquake countermeasure and risk mitigation.展开更多
When the sliding bearing is fixed only at the top of the middle column of the underground structure,the cracks at the side end of the middle plate should be aggravated while the seismic damage of the mid-column should...When the sliding bearing is fixed only at the top of the middle column of the underground structure,the cracks at the side end of the middle plate should be aggravated while the seismic damage of the mid-column should be alleviated.To enhance the seismic performance of the mid-plate,a new isolation design method has been mentioned while the elastic sliding bearings are set at the top of the mid-columns and between the side end of the mid-plate and the side wall at the same time.By establishing a nonlinear finite element analysis model for the static-dynamic coupling interaction system,the seismic response characteristics of the cast-in-place station structure without a sliding bearing have been analyzed and compared with those of the station structure with the sliding bearing fixed only at the top of the middle columns,and those of the station structure with sliding bearing be fixed between the mid-plate and the sidewall at the same time.The results show that the new isolation station structures suffer fewer earthquake damages at the mid-plate and mid-columns at the same time,which can improve the overall seismic performance of the subway station structure.展开更多
This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is dev...This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is developed for all Lead-Rubber Bearing (LRB) seismic isolation system on piers and abutments which placed in between super-structure and sub-structure. Design forces, displacements, and drifts are given distinctive consideration in accordance with Caltrans Seismic Design Criteria (2004). Most of all, total displacement on design for all LRBs case is reduced comparing with combined lead-rubber and elastomeric bearing system . Therefore, this represents substantial reduction in cost because of reduction of expansion joint. This presents a summary of analysis and design of seismic isolation system by energy mitigation with LRB on bridges.展开更多
This paper discusses the relation between two-step seismic design and the standard of probability of exceedance, and the relation of three-levels seismic ground motion parameters given by probability method and compre...This paper discusses the relation between two-step seismic design and the standard of probability of exceedance, and the relation of three-levels seismic ground motion parameters given by probability method and comprehensive probability method. The relative size relations of the ground motions with 2%, 10%, 63% probability of exceedance in 50 years, namely large earthquake, moderate earthquake, and small earthquake, are discussed through a practical example of seismic hazard analysis. The methods to determine seismic fortification criterion are discussed.展开更多
The paper discusses how to approach the problem of the social mitigation of seismic risk, in order to reduce damage and grief consequent to earthquakes. An alert protocol, intended as a working hypothesis, is proposed...The paper discusses how to approach the problem of the social mitigation of seismic risk, in order to reduce damage and grief consequent to earthquakes. An alert protocol, intended as a working hypothesis, is proposed based on the experience gained from analysis of the behaviour and social response to the threat before and after the great disaster of the L’Aquila earthquake on 6th April 2009. Authors propose a protocol addressing four levels of increasing alert based on signs of earthquake preparation and social concerns. In this sense, it works as an intensity scale and does not strictly relate to earthquake size (magnitude) or seismic hazard. The proposed alert protocol provides sensible measures for reducing vulnerability, which is the only factor that can be more or less efficiently controlled, based on structural and behavioural adjustments. Factors indicating the difficult relationship between politicians, scientific community and citizens are considered: 1) a serious gap between researchers and citizens;2) measures adopted by local administrators and the National Civil Protection Service not agreed by the population;3) misunderstanding originated from a lack of clarity of communication about scientific terminology;and 4) the lack of an alert procedure protocol. In the current situation, all these problems are crucial and contribute to the unpreparedness to face a seismic event, and thus greatly increase the risk. The adoption and implementation of an alert procedure protocol requires a preliminary assessment of the context and should be adapted to the local sensibility and culture. The application of a protocol may reduce the contrasts between preventive measures and individual responsibilities, making mitigation measures more feasible and socially acceptable. In this paper, risk evaluation is not strictly related to probabilistic or deterministic predictions. In fact, this is a result of a project that comes from the general analysis of risk and is not intended to give an alternative hazard estimate method. This paper proposes an alert protocol addressing four levels of increasing alert based on signs of earthquake generating preparation and social concerns. Finally, there is a suggestion on how to gradually communicate the threat and get citizens involved in the risk mitigation process.展开更多
Metropolitans are a result of fast economic development in China. Many metropolitans have emerged in the eastern part of China. Earthquake disasters in metropolitans are more complicated and serious than those in a sm...Metropolitans are a result of fast economic development in China. Many metropolitans have emerged in the eastern part of China. Earthquake disasters in metropolitans are more complicated and serious than those in a smaller city, and the impact of earthquake disaster on the economy and society is large. The characteristics of earthquake disasters and countermeasures to protect against and mitigate disaster in the metropolitan, as well as some key research fields in the earthquake disaster protection and mitigation, are discussed.展开更多
As an earthquake-prone country, China has made sustained efforts in the study of earthquakes and disaster mitigation during the past several decades, with China Seismological Bureau (CSB) as the backbone of these effo...As an earthquake-prone country, China has made sustained efforts in the study of earthquakes and disaster mitigation during the past several decades, with China Seismological Bureau (CSB) as the backbone of these efforts. Working towards this purpose, a series of key projects were implemented in the “Ninth Five-Year Plan” (1995-2000) to upgrade earthquake monitoring systems and to improve the supporting infrastructure, significant results in earthquake science were achieved. In the new century, we have worked out a blueprint for earthquake preparedness and disaster mitigation in the “Tenth Five-Year Plan”, which emphases 3 systems (i.e. Seismic Monitoring & Prediction, Seismic Hazards Prevention, Emergency Response), and 10 key projects in earthquake science and technology.展开更多
文摘For earthquake-prone countries of the world, it is crucial to develop countermeasures and to share experiences in seismic hazard mitigation. The measures for seismic hazard mitigation are related to many factors, e.g., social, economic, and political. Research focused on modern science and technology paves the way for a better understanding of the earthquake phenomenon and helps to plan against its effects in seismically active areas.In this paper, we consider some of the events that occurred in earthquake-prone countries, both developing and developed, which caused devastation to the society and economy. These are mainly major events that have affected a considerable portion of the gross domestic product of these economies.Measures to mitigate seismic hazard are stressed and suggested. In addition, experiences in seismic hazard mitigation in Uganda and the rest of the world are discussed in general terms. Attention is given to geotectonic settings as well as the work of seismic hazard and disaster
文摘Analysis of seismic data and seismicity characteristics in China, we gave a method to deal with seismic patterns by calculating density at grid nodes. Number of earthquakes and epicenter distribution are considered comprehensively in this method. Effect of datum accuracy is stressed on parameter confirmation. Seismic patterns from this method are stable and can reflect seismic characteristics reliably. These seismic patterns are the base of quantitative analysis of seismicity. It can be applied in seismic tendency analysis and medium-long term earthquake prediction, earthquake countermeasure and risk mitigation.
基金financially supported by the National Natural Science Foundation of China(Nos.51778290,51978333)。
文摘When the sliding bearing is fixed only at the top of the middle column of the underground structure,the cracks at the side end of the middle plate should be aggravated while the seismic damage of the mid-column should be alleviated.To enhance the seismic performance of the mid-plate,a new isolation design method has been mentioned while the elastic sliding bearings are set at the top of the mid-columns and between the side end of the mid-plate and the side wall at the same time.By establishing a nonlinear finite element analysis model for the static-dynamic coupling interaction system,the seismic response characteristics of the cast-in-place station structure without a sliding bearing have been analyzed and compared with those of the station structure with the sliding bearing fixed only at the top of the middle columns,and those of the station structure with sliding bearing be fixed between the mid-plate and the sidewall at the same time.The results show that the new isolation station structures suffer fewer earthquake damages at the mid-plate and mid-columns at the same time,which can improve the overall seismic performance of the subway station structure.
文摘This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is developed for all Lead-Rubber Bearing (LRB) seismic isolation system on piers and abutments which placed in between super-structure and sub-structure. Design forces, displacements, and drifts are given distinctive consideration in accordance with Caltrans Seismic Design Criteria (2004). Most of all, total displacement on design for all LRBs case is reduced comparing with combined lead-rubber and elastomeric bearing system . Therefore, this represents substantial reduction in cost because of reduction of expansion joint. This presents a summary of analysis and design of seismic isolation system by energy mitigation with LRB on bridges.
文摘This paper discusses the relation between two-step seismic design and the standard of probability of exceedance, and the relation of three-levels seismic ground motion parameters given by probability method and comprehensive probability method. The relative size relations of the ground motions with 2%, 10%, 63% probability of exceedance in 50 years, namely large earthquake, moderate earthquake, and small earthquake, are discussed through a practical example of seismic hazard analysis. The methods to determine seismic fortification criterion are discussed.
文摘The paper discusses how to approach the problem of the social mitigation of seismic risk, in order to reduce damage and grief consequent to earthquakes. An alert protocol, intended as a working hypothesis, is proposed based on the experience gained from analysis of the behaviour and social response to the threat before and after the great disaster of the L’Aquila earthquake on 6th April 2009. Authors propose a protocol addressing four levels of increasing alert based on signs of earthquake preparation and social concerns. In this sense, it works as an intensity scale and does not strictly relate to earthquake size (magnitude) or seismic hazard. The proposed alert protocol provides sensible measures for reducing vulnerability, which is the only factor that can be more or less efficiently controlled, based on structural and behavioural adjustments. Factors indicating the difficult relationship between politicians, scientific community and citizens are considered: 1) a serious gap between researchers and citizens;2) measures adopted by local administrators and the National Civil Protection Service not agreed by the population;3) misunderstanding originated from a lack of clarity of communication about scientific terminology;and 4) the lack of an alert procedure protocol. In the current situation, all these problems are crucial and contribute to the unpreparedness to face a seismic event, and thus greatly increase the risk. The adoption and implementation of an alert procedure protocol requires a preliminary assessment of the context and should be adapted to the local sensibility and culture. The application of a protocol may reduce the contrasts between preventive measures and individual responsibilities, making mitigation measures more feasible and socially acceptable. In this paper, risk evaluation is not strictly related to probabilistic or deterministic predictions. In fact, this is a result of a project that comes from the general analysis of risk and is not intended to give an alternative hazard estimate method. This paper proposes an alert protocol addressing four levels of increasing alert based on signs of earthquake generating preparation and social concerns. Finally, there is a suggestion on how to gradually communicate the threat and get citizens involved in the risk mitigation process.
文摘Metropolitans are a result of fast economic development in China. Many metropolitans have emerged in the eastern part of China. Earthquake disasters in metropolitans are more complicated and serious than those in a smaller city, and the impact of earthquake disaster on the economy and society is large. The characteristics of earthquake disasters and countermeasures to protect against and mitigate disaster in the metropolitan, as well as some key research fields in the earthquake disaster protection and mitigation, are discussed.
文摘As an earthquake-prone country, China has made sustained efforts in the study of earthquakes and disaster mitigation during the past several decades, with China Seismological Bureau (CSB) as the backbone of these efforts. Working towards this purpose, a series of key projects were implemented in the “Ninth Five-Year Plan” (1995-2000) to upgrade earthquake monitoring systems and to improve the supporting infrastructure, significant results in earthquake science were achieved. In the new century, we have worked out a blueprint for earthquake preparedness and disaster mitigation in the “Tenth Five-Year Plan”, which emphases 3 systems (i.e. Seismic Monitoring & Prediction, Seismic Hazards Prevention, Emergency Response), and 10 key projects in earthquake science and technology.