A case study of seismic response of an earth embankment foundation on liquefiable soils in Kansai area,western Japan was presented. Based on a calibrated cyclic elasto-plastic constitutive model for liquefiable sand a...A case study of seismic response of an earth embankment foundation on liquefiable soils in Kansai area,western Japan was presented. Based on a calibrated cyclic elasto-plastic constitutive model for liquefiable sand and Biot dynamic coupled theory,the seismic analysis was carried out by using a dynamic effective stress finite element method under plane strain condition. A recent design study was illustrated in detail for a river earth embankment subjected to seismic excitation on the saturated deposits with liquefiable sands. Simulated results of the embankment foundation during liquefaction were obtained for acceleration,displacement,and excess pore water pressures,which were considered to yield useful results for earthquake geotechnical design. The results show that the foundation soil reaches a fully liquefied state with high excess pore pressure ratios approaching to 1.0 due to the earthquake shaking. At the end of the earthquake,the extensive liquefaction causes about 1.0 m lateral spreading at the toe and 60 cm settlement at the crest of the earth embankment.展开更多
自然资本是人类社会经济可持续发展的基础,其内涵包括作为存量的土地、水等有形自然资源和作为流量的生态产品和系统服务。生态环境导向的开发(Ecologically Oriented Development,EOD)和特定地域单元生态产品价值(Value of Ecosystem P...自然资本是人类社会经济可持续发展的基础,其内涵包括作为存量的土地、水等有形自然资源和作为流量的生态产品和系统服务。生态环境导向的开发(Ecologically Oriented Development,EOD)和特定地域单元生态产品价值(Value of Ecosystem Product in specific geographic units,VEP)是面向自然资本全周期治理的制度创新,旨在通过统筹存量保护与流量利用,实现区域生态、社会、经济的协同发展。国际上主要发达国家的类EOD开发模式在亲市场的制度条件下,在产业关联模式和组织模式方面呈现出显著的自主性、创新性和多元性特征。当前,我国的EOD和VEP实践产生了大量经验,也暴露了很多问题,但已有研究太过碎片化,不足以系统辨识存在的问题并支撑有效的决策。在重新审视EOD和VEP概念及其理论逻辑的基础上,结合对国内外10个典型EOD案例的结构化分析,辨识当前进一步推进EOD开发模式面临的制度、机制方面的问题,包括缺乏支撑有效项目策划和实施的数字认证基建、制度化的评估反馈机制、多样化的治理模式等。本研究在自然资本治理的语境下,探讨了EOD和VEP的作用机理以及两者的融通点,既丰富了自然资本的理论研究,又进一步支撑了战略决策和管理实践。展开更多
基金Projects (40802070, 40841014) supported by the National Natural Science Foundation of ChinaProject (B308) supported by Shanghai Leading Academic Discipline Project, China
文摘A case study of seismic response of an earth embankment foundation on liquefiable soils in Kansai area,western Japan was presented. Based on a calibrated cyclic elasto-plastic constitutive model for liquefiable sand and Biot dynamic coupled theory,the seismic analysis was carried out by using a dynamic effective stress finite element method under plane strain condition. A recent design study was illustrated in detail for a river earth embankment subjected to seismic excitation on the saturated deposits with liquefiable sands. Simulated results of the embankment foundation during liquefaction were obtained for acceleration,displacement,and excess pore water pressures,which were considered to yield useful results for earthquake geotechnical design. The results show that the foundation soil reaches a fully liquefied state with high excess pore pressure ratios approaching to 1.0 due to the earthquake shaking. At the end of the earthquake,the extensive liquefaction causes about 1.0 m lateral spreading at the toe and 60 cm settlement at the crest of the earth embankment.
文摘自然资本是人类社会经济可持续发展的基础,其内涵包括作为存量的土地、水等有形自然资源和作为流量的生态产品和系统服务。生态环境导向的开发(Ecologically Oriented Development,EOD)和特定地域单元生态产品价值(Value of Ecosystem Product in specific geographic units,VEP)是面向自然资本全周期治理的制度创新,旨在通过统筹存量保护与流量利用,实现区域生态、社会、经济的协同发展。国际上主要发达国家的类EOD开发模式在亲市场的制度条件下,在产业关联模式和组织模式方面呈现出显著的自主性、创新性和多元性特征。当前,我国的EOD和VEP实践产生了大量经验,也暴露了很多问题,但已有研究太过碎片化,不足以系统辨识存在的问题并支撑有效的决策。在重新审视EOD和VEP概念及其理论逻辑的基础上,结合对国内外10个典型EOD案例的结构化分析,辨识当前进一步推进EOD开发模式面临的制度、机制方面的问题,包括缺乏支撑有效项目策划和实施的数字认证基建、制度化的评估反馈机制、多样化的治理模式等。本研究在自然资本治理的语境下,探讨了EOD和VEP的作用机理以及两者的融通点,既丰富了自然资本的理论研究,又进一步支撑了战略决策和管理实践。
