The longitudinal cracks distributed along the dam axis in the corridor of a dam may have potential safety hazards.According to the detection results of crack depth and width and the analysis of monitoring data,a three...The longitudinal cracks distributed along the dam axis in the corridor of a dam may have potential safety hazards.According to the detection results of crack depth and width and the analysis of monitoring data,a three-dimensional finite element model is established for numerical simulation calculation and the influence of cracks on the safety of dam structure is analyzed from different aspects such as deformation,stress value,and distribution range.The calculation results show that the maximum principal tensile stress value and the location of the dam body are basically independent of the change of crack depth(within 1.0 m).Regarding local stress around the corridor,the high upstream water level causes cracks to deepen,resulting in an increase in the maximum tensile stress near the crack tip and an expansion of the tensile stress region.展开更多
This study aims to utilize the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-In SAR)technique and Google Earth optical remote sensing images to analyze the area within 20 km around the epicenter ...This study aims to utilize the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-In SAR)technique and Google Earth optical remote sensing images to analyze the area within 20 km around the epicenter of a M 3.9, earthquake that occurred in Tanchang County, Gansu Province, on December 28, 2020. The objective is to identify potential earthquake-induced landslides, assess their scale, and determine their impact range. The study results reveal the successful identification of two potential landslides in the 20 km radius around the epicenter. Through time-series deformation analysis, it was observed that these potential landslides were significantly influenced by both the earthquake and rainfall. Further estimation of these potential landslides indicates maximum depths of 7.4 m and 14.1 m for the failure surfaces, with volumes of 9.02 × 10~4m~3and 25.5 ×10~4m~3, respectively. Finally, based on the simulation analysis of Massflow software, the maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Shangyaai is 12 m, the area of the final accumulation area is 1.75 × 10~4m~2, and the farthest movement distance is 1124 m. The maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Wangshancun is 8 m, the area of the final accumulation area is 7.89 × 10~4m~2, and the farthest movement distance is 742 m.展开更多
China is physically and socio-economically susceptible to global warming-derived high temperature extremes because of its vast area and high urban population density. This article presents a scenario-based analysis me...China is physically and socio-economically susceptible to global warming-derived high temperature extremes because of its vast area and high urban population density. This article presents a scenario-based analysis method for high temperature extremes aimed at illustrating the latter＇s hazardous potential and exposure across China. Based on probability analysis, high temperature extreme scenarios with return periods of 5, 10, 20, and 50 years were designed, with a high temperature hazard index calculated by integrating two differen- tially-weighted extreme temperature indices （maximum temperature and high temperature days）. To perform the exposure analysis, a land use map was employed to determine the spatial distribution of susceptible human activities under the different scenarios. The results indicate that there are two heat-prone regions and a sub-hotspot occupying a relatively small land area. However, the societal and economic consequences of such an environmental im- pact upon the North China Plain and middle/lower Yangtze River Basin would be substantial due to the concentration of human activities in these areas.展开更多
The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is pres...The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.展开更多
In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addit...In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5（Mw） are expected.High values of SA（spectral acceleration）（0.2 and 1 s periods） and PGA（peak ground acceleration） were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures.展开更多
A mature mathematical technique called copula joint function is introduced in this paper, which is commonly used in the financial risk analysis to estimate uncertainty. The joint function is generalized to the n-dimen...A mature mathematical technique called copula joint function is introduced in this paper, which is commonly used in the financial risk analysis to estimate uncertainty. The joint function is generalized to the n-dimensional Frank’s copula. In addition, we adopt two attenuation models proposed by YU and Boore et al, respectively, and construct a two-dimensional copula joint probabilistic function as an example to illustrate the uncertainty treatment at low probability. The results show that copula joint function gives us a better prediction of peak ground motion than that resultant from the simple linear weight technique which is commonly used in the traditional logic-tree treatment of model uncertainties. In light of widespread application in the risk analysis from financial investment to insurance assessment, we believe that the copula-based technique will have a potential application in the seismic hazard analysis.展开更多
Potential sources are simplified as point sources or linear sources in current probabilistic seismic hazard analysis （PSHA） methods. Focus size of large earthquakes is considerable, and fault rupture attitudes may h...Potential sources are simplified as point sources or linear sources in current probabilistic seismic hazard analysis （PSHA） methods. Focus size of large earthquakes is considerable, and fault rupture attitudes may have great influence upon the seismic hazard of a site which is near the source. Under this circumstance, it is unreasonable to use the simplified potential source models in the PSHA, so a potential rupture surface model is proposed in this paper. Adopting this model, we analyze the seismic hazard near the Chelungpu fault that generated the Chi-Chi （Jiji） earthquake with magnitude 7.6 and the following conclusions are reached. （1） This model is reasonable on the base of focal mechanism, especially for sites near potential earthquakes with large magnitude; （2） The attitudes of potential rupture surfaces have great influence on the results of probabilistic seismic hazard analysis and seismic zoning.展开更多
The traditional approach to probabilistic seismic hazard analysis(PSHA)relies on ground motion records,which restricts its application in regions with sparse seismic records or low seismicity.Recently,the 3D physics-b...The traditional approach to probabilistic seismic hazard analysis(PSHA)relies on ground motion records,which restricts its application in regions with sparse seismic records or low seismicity.Recently,the 3D physics-based simulation(PBS)has been recognized as a more effective tool,which offers the flexibility to generate time histories of simulated ground motions.The PBS methods are essential for obtaining ground motion parameters and compensating for lack of records.In this study,building on the theoretical framework of the China Probabilistic Seismic Hazard Analysis(CPSHA)method,we integrated the hierarchical potential focal region model from the fifth-generation seismic ground motion parameters zonation map of China and an appropriate seismicity model reflecting spatial distribution characteristics.Ground motion parameters at the target scale were calculated using PBS for near-field seismic simulations and ground motion prediction equations(GMPEs)for far-field seismic predictions,accounting for the uncertainties in ground motion attenuation from both methods to compute the seismic hazard of each site.In this manner,we established a comprehensive regional probabilistic seismic hazard analysis method combining PBS and GMPE.Using Tianjin as a case study,a probabilistic seismic hazard analysis was conducted with this method,providing seismic hazard curves for specific sites within each administrative region and zoning maps,which were then compared with the results of the fifth-generation zonation maps.The results indicate that the calculated seismic hazard values are generally consistent with the fifth-generation map at the lower limit,while the upper limit is slightly higher due to the near-fault effect.展开更多
The probabilistic seismic hazard analysis (PSHA) method used in existing seismic ground motion parameters zonation map of China (the traditional PSHA-CN method) is based on a two-dimensional area seismic source framew...The probabilistic seismic hazard analysis (PSHA) method used in existing seismic ground motion parameters zonation map of China (the traditional PSHA-CN method) is based on a two-dimensional area seismic source framework and does not account for the rupture dimension of large earthquakes,which may lead to underestimation of seismic hazard at near-fault sites.By employing stochastic sampling to integrate three-dimensional fault sources and two-dimensional area seismic sources,a new PSHA-CN method was developed in recent years,but it faces limitations in accuracy and computational ef ciency due to sampling constraints,particularly for low probability of exceedance scenarios or large earthquakes with long return periods.To enhance the computational ef ciency of the new PSHA-CN method,this study developed a novel spatial integration algorithm for PSHA.The algorithm considers rupture dimension,enables ef cient fault geometry modeling using the Frankel Fault Surface (FFS) and Stirling Fault Surface (SFS) models,and maintains compatibility with the traditional PSHA-CN framework.Validation against test cases from the Pacific Earthquake Engineering Research Center (PEER) demonstrated the algorithm’s reliability.Furthermore,the algorithm was applied to assess seismic hazard in the Changsha-Zhuzhou-Xiangtan metropolitan region in Hunan Province to validate its performance in regions with moderate seismic activity in China.A comparative analysis of the new algorithm results with those of the traditional PSHA-CN method revealed that the PSHA-CN method underestimates near-fault seismic hazards.The proposed algorithm will be implemented in next-generation seismic ground motion parameters zonation map in China.展开更多
Objective:To analyze the existing risks in breast milk management at the neonatal department and provide corresponding countermeasures.Methods:22 risk events were identified in 7 risk links in the process of bottle-fe...Objective:To analyze the existing risks in breast milk management at the neonatal department and provide corresponding countermeasures.Methods:22 risk events were identified in 7 risk links in the process of bottle-feeding of breast milk.Hazard Vulnerability Analysis based on the Kaiser model was applied to investigate and evaluate the risk events.Results:High-risk events include breast milk quality inspection,hand hygiene during collection,disinfection of collectors,cold chain management,hand hygiene during the reception,breast milk closed-loop management,and post-collection disposal.Root cause analysis of high-risk events was conducted and breast milk management strategies outside the hospital and within the neonatal department were proposed.Conclusion:Hazard Vulnerability Analysis based on the Kaiser model can identify and assess neonatal breast milk management risks effectively,which helps improve the management of neonatal breast milk.It is conducive to the safe development and promotion of bottle feeding of breast milk for neonates,ensuring the quality of medical services and the safety of children.展开更多
First, a calculation method for available safety egress time (shortly called ASET) and requirement safety egress time (shortly called RSET) in a one-room building fire is proposed and a model for predicting the death ...First, a calculation method for available safety egress time (shortly called ASET) and requirement safety egress time (shortly called RSET) in a one-room building fire is proposed and a model for predicting the death number caused by the fire is established in this paper. Then, numerical simulations are performed, and the following laws are discovered: (1) At the beginning of the fire, the smoke layer falls slowly; as the fire develops, it falls rapidly. (2) The hypotheses on the fire source, the combustion properties of the combustibles, and the width of the exit and the person number in the room are important factors which affect the death number in the fire.展开更多
Based on the seismic source model in the Fifth Generation Seismic Ground Motion Parameters Zonation Map of China(FGSGMPZMC),a new seismic fault model,the new zonation of seismic risk areas(SRAs),and the estimation of ...Based on the seismic source model in the Fifth Generation Seismic Ground Motion Parameters Zonation Map of China(FGSGMPZMC),a new seismic fault model,the new zonation of seismic risk areas(SRAs),and the estimation of seismicity rates for 2021-2030,this study constructed a new time-dependent seismic source model of China’s mainland,and used the probabilistic seismic hazard analysis method to calculate seismic hazard by selecting the ground motion models(GMMs)suitable for seismic sources in China.It also provided the probabilities of China’s mainland being affected by earthquakes of modified Mercalli intensity(MMI)Ⅵ,Ⅶ,Ⅷ,Ⅸ,and≥Ⅹin 2021-2030.The spatial pattern of seismic hazards presented in this article is similar to the pattern of the FGSGMPZMC,but shows more details.The seismic hazards in this study are higher than those in the FGSGMPZMC in the SRAs and fault zones that can produce large earthquakes.This indicates that the seismic source model construction in this study is scientific and reasonable.There are certain similarities between the results in this study and those of Rong et al.(2020)and Feng et al.(2020),but also disparities for specific sites due to differences in seismic source models,seismicity parameters,and GMMs.The results of seismic hazard may serve as parameter input for future seismic risk assessments.The hazard results can also be used as a basis for the formulation of earthquake prevention and mitigation policies for China’s mainland.展开更多
The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spec...The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spectrum to select ground motion records based on the target spectrum.This research demonstrates the influence of adopting different weighted factors for various period ranges during matching selected ground motions with the target hazard spectrum.The event data from the Next Generation Attenuation West 2(NGA-West 2)database is used as the basis for ground motion selection,and hazard de-aggregation is conducted to estimate the event parameters of interest,which are then used to construct the target intensity measure(IM).The target IMs are then used to select ground motion records with different weighted vector-valued objective functions.The weights are altered to account for the relative importance of IM in accordance with the structural analysis application of steel moment resisting frame(SMRF)buildings.Instead of an ordinary objective function for the matching spectrum,a novel model is introduced and compared with the conventional cost function.The results indicate that when applying the new cost function for ground motion selection,it places higher demands on structures compared to the conventional cost function.Moreover,submitting more weights to the first-mode period of structures increases engineering demand parameters.Findings demonstrate that weight factors allocated to different period ranges can successfully account for period elongation and higher mode effects.展开更多
A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium erupt...A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption.展开更多
Histamine(HA)is a biogenic amine formed during the metabolism of microorganisms,excessive intake of which can cause headache,diarrhea,and,in severe cases,food poisoning.The commonly used instrumental detection methods...Histamine(HA)is a biogenic amine formed during the metabolism of microorganisms,excessive intake of which can cause headache,diarrhea,and,in severe cases,food poisoning.The commonly used instrumental detection methods are expensive and time-consuming,making it challenging to realize on-site inspection.In this work,we reported a colorimetric test strip-based detection method for HA by chemical recognition of the amine and imidazole groups of HA.Polydopamine-coated gold nanoparticles that were modified with carboxyl group-terminated polyethylene glycol(Au@PDA-C NPs)were utilized as labels to capture HA through the N-hydroxysuccinimide/1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride(NHS/EDC)reaction between HA and the carboxyl group of the Au@PDA-C NPs.The chelate from nitrilotriacetic acid(NTA)and Cu^(2+)at the T-line could then specifically bind the imidazole moiety of HA in the complex of HA and Au@PDA-C NPs,enabling the T-line to present the colorimetric characteristics of Au@PDA-C NPs.The gray value of the T-line in the test strip showed a good linear relationship with the HA concentration in the range of 0–100μg/m L,with the standard curve equation of Y=27.94X+463.0 and the correlation coefficient of R^(2)=0.944.The detection limit and quantification limit of HA were 1.16μg/m L(signal-to-noise ratio(S/N)=3)and 3.88μg/m L(S/N=10),respectively.The two-site chemical recognition method could also achieve specific detection of HA in commercially available samples,showing potential application as an on-site analysis tool for HA.展开更多
Since there are few studies on the performance-based seismic evaluation of the long-span suspension bridge system under two-level earthquake hazard in Chinese code,the developed procedure of this study can be regarded...Since there are few studies on the performance-based seismic evaluation of the long-span suspension bridge system under two-level earthquake hazard in Chinese code,the developed procedure of this study can be regarded as a general program to assess the seismic performance of the overall system for long-span suspension bridges.In the procedure,the probabilistic seismic demand models of multiple bridge components were developed by nonlinear time-history analyses incorporating the related uncertainties,and the component-level fragility curves were calculated by the reasonable definition of limit states of the corresponding components in combination with seismic hazard analysis.The bridge repair cost ratios used to evaluate the system seismic performance were derived through the performance-based methodology and the damage probability of critical components.Furthermore,the repair cost ratios of the overall bridge system that was retrofitted with fluid viscous dampers for the main bridge and changed restraint systems for the approach bridges were compared.The results show that peak ground velocity and peak ground acceleration can be selected as the optimal intensity measurements of long-span suspension bridges using the TOPSIS(technique for order preference by similarity to an ideal solution).The bridge repair cost ratios can serve as accurate evaluation indicators to provide an efficient evaluation of retrofit measures.The seismic evaluation of long-span bridges is misled when ignoring the interaction of adjacent structures.However,the repair cost ratios of a bridge system that has optimum seismic performance are less sensitive to the relative importance of adjacent structures.展开更多
GIS technology provides a powenful tool for disaster hazard assessment and mitigation. A GIS based system is developed for typhoon data management and analysis, typhoon simulation and hazard assessment for southeast c...GIS technology provides a powenful tool for disaster hazard assessment and mitigation. A GIS based system is developed for typhoon data management and analysis, typhoon simulation and hazard assessment for southeast coast of China in this paper. A typhoon database by Microsoft Access is designed. Data manipulation and analysis, typhoon simulation and hazard assessment, and visualization of results are implemented on GIS platform. This GIS-based typhoon database and analysis system greatly facilitates typhoon hazard assessment.展开更多
Based on the modern earthquake catalogue,the incomplete centroidal voronoi tessellation(ICVT)method was used in this study to estimate the seismic hazard in Sichuan-Yunnan region of China.We calculated spatial distrib...Based on the modern earthquake catalogue,the incomplete centroidal voronoi tessellation(ICVT)method was used in this study to estimate the seismic hazard in Sichuan-Yunnan region of China.We calculated spatial distributions of the total seismic hazard and background seismic hazard in this area.The Bayesian delaunay tessellation smoothing method put forward by Ogata was used to calculate the spatial distributions of b-value.The results show that seismic hazards in Sichuan-Yunan region are high,and areas with relatively high hazard values are distributed along the main faults,while seismic hazards in Sichuan basin are relatively low.展开更多
Major mineral hazard identifications should consider perilous types of fatal accidents in collieries from its definition, and then set existent hazardous objects and their relevant amount as referenced factors. Elimin...Major mineral hazard identifications should consider perilous types of fatal accidents in collieries from its definition, and then set existent hazardous objects and their relevant amount as referenced factors. Eliminating hazards in systems and decreasing risks are their essential purposes with help of hazard identification, risk evaluation and management. By pre-control on major hazards, fatal accidents are avoided, stuffs＇ safety and healthy are protected, levels of safe management are enhanced, and perpetual systems are built up finally. However, choosing the proper identification and evaluation is a problem all along. Based on specific condition in Jiangou Coal Mine, method of LEC was applied for hazard identification and evaluation in the pre-blasting process within horizontal section top-coal mechanized caving of steep seams. And control measures to of each hazard were put forward. The identification method combining qualitative and quantitative analysis. So, it is practical and operable for the method to develop the given scientific research and has a distinctive impact on high efficiency and safety products for pre-blasting in horizontal section top-coal mechanized caving of steep seams.展开更多
Since the disastrous aftermath of the 2004 Sumatra Tsunami(Indonesia)and the 2011 Tohoku Tsunami(Japan),China has made much effort to mitigate tsunami hazards.We briefly reviewed the progress of cataloguing,modeling,e...Since the disastrous aftermath of the 2004 Sumatra Tsunami(Indonesia)and the 2011 Tohoku Tsunami(Japan),China has made much effort to mitigate tsunami hazards.We briefly reviewed the progress of cataloguing,modeling,early warning and hazard analysis for tsunamis in China.Compiling a Chinese tsunami catalogue is a challenge at present due to a large number of inconsistent research results.In China,the numerical models widely used in engineering and related studies are developed by other countries,and the development of a domestic model is being funded by the Chinese government.The tsunami early warning system has been set up and used during the recent tsunami events,such as the Chile earthquake on February 27,2010.展开更多
基金Zhejiang Provincial Natural Science Foundation of China for Young Scholars(Project No.:LQ20A020009)National College Students’Innovation and Entrepreneurship Training Program(Project No.:202311842014X)。
文摘The longitudinal cracks distributed along the dam axis in the corridor of a dam may have potential safety hazards.According to the detection results of crack depth and width and the analysis of monitoring data,a three-dimensional finite element model is established for numerical simulation calculation and the influence of cracks on the safety of dam structure is analyzed from different aspects such as deformation,stress value,and distribution range.The calculation results show that the maximum principal tensile stress value and the location of the dam body are basically independent of the change of crack depth(within 1.0 m).Regarding local stress around the corridor,the high upstream water level causes cracks to deepen,resulting in an increase in the maximum tensile stress near the crack tip and an expansion of the tensile stress region.
基金supported by the Natural Science Foundation of Gansu Province (22JR5RA326)The geological disaster prevention projects of Gansu Provincial Bureau of Geology and Mineral Resources (2023-2-9)。
文摘This study aims to utilize the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-In SAR)technique and Google Earth optical remote sensing images to analyze the area within 20 km around the epicenter of a M 3.9, earthquake that occurred in Tanchang County, Gansu Province, on December 28, 2020. The objective is to identify potential earthquake-induced landslides, assess their scale, and determine their impact range. The study results reveal the successful identification of two potential landslides in the 20 km radius around the epicenter. Through time-series deformation analysis, it was observed that these potential landslides were significantly influenced by both the earthquake and rainfall. Further estimation of these potential landslides indicates maximum depths of 7.4 m and 14.1 m for the failure surfaces, with volumes of 9.02 × 10~4m~3and 25.5 ×10~4m~3, respectively. Finally, based on the simulation analysis of Massflow software, the maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Shangyaai is 12 m, the area of the final accumulation area is 1.75 × 10~4m~2, and the farthest movement distance is 1124 m. The maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Wangshancun is 8 m, the area of the final accumulation area is 7.89 × 10~4m~2, and the farthest movement distance is 742 m.
基金National Natural Science Foundation of China, No.41071324 No.41201550+5 种基金 No.40730526 Humanities and Social Sciences Project from the Ministry of Education, No.12YJCZtt257 The Innovation Program of Shanghai Municipal Education Commission, No. 13YZ061 No.13ZZ035 Open Fund of Key Laboratory of Geographic Information Science, East China Normal University, No.KLGIS2011A04 The Fundamental Re- search Funds for the Central Universities, and the Key Subject Development Project of the Shanghai Munici- pal Education Commission, No.J50402
文摘China is physically and socio-economically susceptible to global warming-derived high temperature extremes because of its vast area and high urban population density. This article presents a scenario-based analysis method for high temperature extremes aimed at illustrating the latter＇s hazardous potential and exposure across China. Based on probability analysis, high temperature extreme scenarios with return periods of 5, 10, 20, and 50 years were designed, with a high temperature hazard index calculated by integrating two differen- tially-weighted extreme temperature indices （maximum temperature and high temperature days）. To perform the exposure analysis, a land use map was employed to determine the spatial distribution of susceptible human activities under the different scenarios. The results indicate that there are two heat-prone regions and a sub-hotspot occupying a relatively small land area. However, the societal and economic consequences of such an environmental im- pact upon the North China Plain and middle/lower Yangtze River Basin would be substantial due to the concentration of human activities in these areas.
基金National Outstanding Youth Science Foundation (59825105).
文摘The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.
文摘In this study, we present a PSHA（Probabilistic Seismic Hazard Analysis） for the city of San Juan, which is located in the central-western region of Argentina（30°S-35.5°S; 66.5°W-71°W）. In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5（Mw） are expected.High values of SA（spectral acceleration）（0.2 and 1 s periods） and PGA（peak ground acceleration） were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures.
基金Project of Institute of Crustal Dynamics, China Earthquake Administration (ZDJ2007-1)One Hundred Individual Program of Chinese Academy of Sciences (99M2009M02) National Natural Science Foundation of China (40574022)
文摘A mature mathematical technique called copula joint function is introduced in this paper, which is commonly used in the financial risk analysis to estimate uncertainty. The joint function is generalized to the n-dimensional Frank’s copula. In addition, we adopt two attenuation models proposed by YU and Boore et al, respectively, and construct a two-dimensional copula joint probabilistic function as an example to illustrate the uncertainty treatment at low probability. The results show that copula joint function gives us a better prediction of peak ground motion than that resultant from the simple linear weight technique which is commonly used in the traditional logic-tree treatment of model uncertainties. In light of widespread application in the risk analysis from financial investment to insurance assessment, we believe that the copula-based technique will have a potential application in the seismic hazard analysis.
基金Foundation item: Joint Seismological Science Foundation of China (104065)Social Public Welfare Special Foundation of the Na-tional Research Institutes (2005DIB3J119).
文摘Potential sources are simplified as point sources or linear sources in current probabilistic seismic hazard analysis （PSHA） methods. Focus size of large earthquakes is considerable, and fault rupture attitudes may have great influence upon the seismic hazard of a site which is near the source. Under this circumstance, it is unreasonable to use the simplified potential source models in the PSHA, so a potential rupture surface model is proposed in this paper. Adopting this model, we analyze the seismic hazard near the Chelungpu fault that generated the Chi-Chi （Jiji） earthquake with magnitude 7.6 and the following conclusions are reached. （1） This model is reasonable on the base of focal mechanism, especially for sites near potential earthquakes with large magnitude; （2） The attitudes of potential rupture surfaces have great influence on the results of probabilistic seismic hazard analysis and seismic zoning.
基金supported by the National Key Research and Development Program of China under Grant No.2023YFC3805200the National Natural Science Foundation of China under Grant Nos.52178495 and 52308513the Postdoctoral Fellowship Program of CPSF under Grant No.GZB20230487。
文摘The traditional approach to probabilistic seismic hazard analysis(PSHA)relies on ground motion records,which restricts its application in regions with sparse seismic records or low seismicity.Recently,the 3D physics-based simulation(PBS)has been recognized as a more effective tool,which offers the flexibility to generate time histories of simulated ground motions.The PBS methods are essential for obtaining ground motion parameters and compensating for lack of records.In this study,building on the theoretical framework of the China Probabilistic Seismic Hazard Analysis(CPSHA)method,we integrated the hierarchical potential focal region model from the fifth-generation seismic ground motion parameters zonation map of China and an appropriate seismicity model reflecting spatial distribution characteristics.Ground motion parameters at the target scale were calculated using PBS for near-field seismic simulations and ground motion prediction equations(GMPEs)for far-field seismic predictions,accounting for the uncertainties in ground motion attenuation from both methods to compute the seismic hazard of each site.In this manner,we established a comprehensive regional probabilistic seismic hazard analysis method combining PBS and GMPE.Using Tianjin as a case study,a probabilistic seismic hazard analysis was conducted with this method,providing seismic hazard curves for specific sites within each administrative region and zoning maps,which were then compared with the results of the fifth-generation zonation maps.The results indicate that the calculated seismic hazard values are generally consistent with the fifth-generation map at the lower limit,while the upper limit is slightly higher due to the near-fault effect.
基金Funding for this research was provided by the National Key R&D Program of China(Grant No.2022YFC3003505)This research was also funded by the National Natural Science Foundation of China(Grant No.41974065)the Special Fund of the Institute of Geophysics,China Earthquake Administration(Grant No.DQJB23Y32).
文摘The probabilistic seismic hazard analysis (PSHA) method used in existing seismic ground motion parameters zonation map of China (the traditional PSHA-CN method) is based on a two-dimensional area seismic source framework and does not account for the rupture dimension of large earthquakes,which may lead to underestimation of seismic hazard at near-fault sites.By employing stochastic sampling to integrate three-dimensional fault sources and two-dimensional area seismic sources,a new PSHA-CN method was developed in recent years,but it faces limitations in accuracy and computational ef ciency due to sampling constraints,particularly for low probability of exceedance scenarios or large earthquakes with long return periods.To enhance the computational ef ciency of the new PSHA-CN method,this study developed a novel spatial integration algorithm for PSHA.The algorithm considers rupture dimension,enables ef cient fault geometry modeling using the Frankel Fault Surface (FFS) and Stirling Fault Surface (SFS) models,and maintains compatibility with the traditional PSHA-CN framework.Validation against test cases from the Pacific Earthquake Engineering Research Center (PEER) demonstrated the algorithm’s reliability.Furthermore,the algorithm was applied to assess seismic hazard in the Changsha-Zhuzhou-Xiangtan metropolitan region in Hunan Province to validate its performance in regions with moderate seismic activity in China.A comparative analysis of the new algorithm results with those of the traditional PSHA-CN method revealed that the PSHA-CN method underestimates near-fault seismic hazards.The proposed algorithm will be implemented in next-generation seismic ground motion parameters zonation map in China.
文摘Objective:To analyze the existing risks in breast milk management at the neonatal department and provide corresponding countermeasures.Methods:22 risk events were identified in 7 risk links in the process of bottle-feeding of breast milk.Hazard Vulnerability Analysis based on the Kaiser model was applied to investigate and evaluate the risk events.Results:High-risk events include breast milk quality inspection,hand hygiene during collection,disinfection of collectors,cold chain management,hand hygiene during the reception,breast milk closed-loop management,and post-collection disposal.Root cause analysis of high-risk events was conducted and breast milk management strategies outside the hospital and within the neonatal department were proposed.Conclusion:Hazard Vulnerability Analysis based on the Kaiser model can identify and assess neonatal breast milk management risks effectively,which helps improve the management of neonatal breast milk.It is conducive to the safe development and promotion of bottle feeding of breast milk for neonates,ensuring the quality of medical services and the safety of children.
文摘First, a calculation method for available safety egress time (shortly called ASET) and requirement safety egress time (shortly called RSET) in a one-room building fire is proposed and a model for predicting the death number caused by the fire is established in this paper. Then, numerical simulations are performed, and the following laws are discovered: (1) At the beginning of the fire, the smoke layer falls slowly; as the fire develops, it falls rapidly. (2) The hypotheses on the fire source, the combustion properties of the combustibles, and the width of the exit and the person number in the room are important factors which affect the death number in the fire.
基金sponsored by the Special Fund of the Institute of Geophysics,China Earthquake Administration(Grant Nos.DQJB22Z03 and DQJB22B25)。
文摘Based on the seismic source model in the Fifth Generation Seismic Ground Motion Parameters Zonation Map of China(FGSGMPZMC),a new seismic fault model,the new zonation of seismic risk areas(SRAs),and the estimation of seismicity rates for 2021-2030,this study constructed a new time-dependent seismic source model of China’s mainland,and used the probabilistic seismic hazard analysis method to calculate seismic hazard by selecting the ground motion models(GMMs)suitable for seismic sources in China.It also provided the probabilities of China’s mainland being affected by earthquakes of modified Mercalli intensity(MMI)Ⅵ,Ⅶ,Ⅷ,Ⅸ,and≥Ⅹin 2021-2030.The spatial pattern of seismic hazards presented in this article is similar to the pattern of the FGSGMPZMC,but shows more details.The seismic hazards in this study are higher than those in the FGSGMPZMC in the SRAs and fault zones that can produce large earthquakes.This indicates that the seismic source model construction in this study is scientific and reasonable.There are certain similarities between the results in this study and those of Rong et al.(2020)and Feng et al.(2020),but also disparities for specific sites due to differences in seismic source models,seismicity parameters,and GMMs.The results of seismic hazard may serve as parameter input for future seismic risk assessments.The hazard results can also be used as a basis for the formulation of earthquake prevention and mitigation policies for China’s mainland.
基金financial support from Teesside University to support the Ph.D. program of the first author.
文摘The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spectrum to select ground motion records based on the target spectrum.This research demonstrates the influence of adopting different weighted factors for various period ranges during matching selected ground motions with the target hazard spectrum.The event data from the Next Generation Attenuation West 2(NGA-West 2)database is used as the basis for ground motion selection,and hazard de-aggregation is conducted to estimate the event parameters of interest,which are then used to construct the target intensity measure(IM).The target IMs are then used to select ground motion records with different weighted vector-valued objective functions.The weights are altered to account for the relative importance of IM in accordance with the structural analysis application of steel moment resisting frame(SMRF)buildings.Instead of an ordinary objective function for the matching spectrum,a novel model is introduced and compared with the conventional cost function.The results indicate that when applying the new cost function for ground motion selection,it places higher demands on structures compared to the conventional cost function.Moreover,submitting more weights to the first-mode period of structures increases engineering demand parameters.Findings demonstrate that weight factors allocated to different period ranges can successfully account for period elongation and higher mode effects.
基金This co-joint product is sponsored by a Natural Science Foundation of China(40172033)a spe-cial item for commonweal research from the Adminis-tration of Science and Technology of China(2002DI-A20009-20).
文摘A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption.
基金supported by the Zhejiang Gongshang University(QRK22006)the Eagle Plan Cultivation Project of Zhejiang Provincial Administration for Market Regulation(CY2023005)。
文摘Histamine(HA)is a biogenic amine formed during the metabolism of microorganisms,excessive intake of which can cause headache,diarrhea,and,in severe cases,food poisoning.The commonly used instrumental detection methods are expensive and time-consuming,making it challenging to realize on-site inspection.In this work,we reported a colorimetric test strip-based detection method for HA by chemical recognition of the amine and imidazole groups of HA.Polydopamine-coated gold nanoparticles that were modified with carboxyl group-terminated polyethylene glycol(Au@PDA-C NPs)were utilized as labels to capture HA through the N-hydroxysuccinimide/1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride(NHS/EDC)reaction between HA and the carboxyl group of the Au@PDA-C NPs.The chelate from nitrilotriacetic acid(NTA)and Cu^(2+)at the T-line could then specifically bind the imidazole moiety of HA in the complex of HA and Au@PDA-C NPs,enabling the T-line to present the colorimetric characteristics of Au@PDA-C NPs.The gray value of the T-line in the test strip showed a good linear relationship with the HA concentration in the range of 0–100μg/m L,with the standard curve equation of Y=27.94X+463.0 and the correlation coefficient of R^(2)=0.944.The detection limit and quantification limit of HA were 1.16μg/m L(signal-to-noise ratio(S/N)=3)and 3.88μg/m L(S/N=10),respectively.The two-site chemical recognition method could also achieve specific detection of HA in commercially available samples,showing potential application as an on-site analysis tool for HA.
基金Basic Scientific Research Service Project of Centrallevel Public Welfare Research Institute(No.2016-9018)
文摘Since there are few studies on the performance-based seismic evaluation of the long-span suspension bridge system under two-level earthquake hazard in Chinese code,the developed procedure of this study can be regarded as a general program to assess the seismic performance of the overall system for long-span suspension bridges.In the procedure,the probabilistic seismic demand models of multiple bridge components were developed by nonlinear time-history analyses incorporating the related uncertainties,and the component-level fragility curves were calculated by the reasonable definition of limit states of the corresponding components in combination with seismic hazard analysis.The bridge repair cost ratios used to evaluate the system seismic performance were derived through the performance-based methodology and the damage probability of critical components.Furthermore,the repair cost ratios of the overall bridge system that was retrofitted with fluid viscous dampers for the main bridge and changed restraint systems for the approach bridges were compared.The results show that peak ground velocity and peak ground acceleration can be selected as the optimal intensity measurements of long-span suspension bridges using the TOPSIS(technique for order preference by similarity to an ideal solution).The bridge repair cost ratios can serve as accurate evaluation indicators to provide an efficient evaluation of retrofit measures.The seismic evaluation of long-span bridges is misled when ignoring the interaction of adjacent structures.However,the repair cost ratios of a bridge system that has optimum seismic performance are less sensitive to the relative importance of adjacent structures.
文摘GIS technology provides a powenful tool for disaster hazard assessment and mitigation. A GIS based system is developed for typhoon data management and analysis, typhoon simulation and hazard assessment for southeast coast of China in this paper. A typhoon database by Microsoft Access is designed. Data manipulation and analysis, typhoon simulation and hazard assessment, and visualization of results are implemented on GIS platform. This GIS-based typhoon database and analysis system greatly facilitates typhoon hazard assessment.
基金Ningxia Hui Autonomous Region Key R&D Plan East West cooperation Project(No.2018BFG02011)National Natural Science Foundation of China(No.41674047)China Earthquake Science Experiment Site Project,CEA(Nos.2019CSES0105 and 2019CSES0106).
文摘Based on the modern earthquake catalogue,the incomplete centroidal voronoi tessellation(ICVT)method was used in this study to estimate the seismic hazard in Sichuan-Yunnan region of China.We calculated spatial distributions of the total seismic hazard and background seismic hazard in this area.The Bayesian delaunay tessellation smoothing method put forward by Ogata was used to calculate the spatial distributions of b-value.The results show that seismic hazards in Sichuan-Yunan region are high,and areas with relatively high hazard values are distributed along the main faults,while seismic hazards in Sichuan basin are relatively low.
基金Supported by the National Natural Science Foundation of China （1100202 l） the Doctoral Subject Foundation of the Ministry of Education of China （20070008012） the National High Technology Research and Development Program （2008AA062104）
文摘Major mineral hazard identifications should consider perilous types of fatal accidents in collieries from its definition, and then set existent hazardous objects and their relevant amount as referenced factors. Eliminating hazards in systems and decreasing risks are their essential purposes with help of hazard identification, risk evaluation and management. By pre-control on major hazards, fatal accidents are avoided, stuffs＇ safety and healthy are protected, levels of safe management are enhanced, and perpetual systems are built up finally. However, choosing the proper identification and evaluation is a problem all along. Based on specific condition in Jiangou Coal Mine, method of LEC was applied for hazard identification and evaluation in the pre-blasting process within horizontal section top-coal mechanized caving of steep seams. And control measures to of each hazard were put forward. The identification method combining qualitative and quantitative analysis. So, it is practical and operable for the method to develop the given scientific research and has a distinctive impact on high efficiency and safety products for pre-blasting in horizontal section top-coal mechanized caving of steep seams.
基金supported by the National Natural Science Fund No.51278473the Environmental Protection Research Fund for Public Interest No.201209040the northeast Asia(China-Japan-Korea)cooperative research project of earthquake,tsunami and volcano No.ZRH2014-11.
文摘Since the disastrous aftermath of the 2004 Sumatra Tsunami(Indonesia)and the 2011 Tohoku Tsunami(Japan),China has made much effort to mitigate tsunami hazards.We briefly reviewed the progress of cataloguing,modeling,early warning and hazard analysis for tsunamis in China.Compiling a Chinese tsunami catalogue is a challenge at present due to a large number of inconsistent research results.In China,the numerical models widely used in engineering and related studies are developed by other countries,and the development of a domestic model is being funded by the Chinese government.The tsunami early warning system has been set up and used during the recent tsunami events,such as the Chile earthquake on February 27,2010.
