Pier-Pile integral structures provide construction works with many environmental and landscape advantages. For example, the space required to construct these structures is smaller than that of other bridges due to the...Pier-Pile integral structures provide construction works with many environmental and landscape advantages. For example, the space required to construct these structures is smaller than that of other bridges due to the footing being removed, meaning that it is not necessity to greatly change the surroundings of these bridges. While there are environmental and landscape advantages, there are also a few demerits for the overall land-scape designs, including demerits in the design of this proposed structure which consists of relatively slender parts. This proposed structure has already been constructed in areas where possibility of a severe earthquake is low. However, some problems that have yet to be examined are related to the use of this proposed structure in areas where earthquakes are frequent. Lacking detailed studies of its behavior during severe earthquakes, it is currently difficult to construct these structures in Japan. Consequently, it is necessary to investigate in detail limited performance about compression and bending moment, and earthquake- resistant performance of these structures in order to resolve these problems. In this paper, It was clarified the relationship between the rigidity of the ground and the effective buckling length by buckling analysis and elasto- plastic finite deformation analysis. Moreover, it was proposed a simplified formula using a proposed characteristic value β and several factors for analysis accuracy. A simplified formula would support to determine the effective buckling length to design the pier using the load-bearing capacity curve based on the slenderness ratio parameter.展开更多
A hierarchical structural decomposition analysis(SDA) model has been developed based on process-level input-output(I-O) tables to analyze the drivers of energy consumption changes in an integrated steel plant during 2...A hierarchical structural decomposition analysis(SDA) model has been developed based on process-level input-output(I-O) tables to analyze the drivers of energy consumption changes in an integrated steel plant during 2011-2013. By combining the principle of hierarchical decomposition into D&L method, a hierarchical decomposition model for multilevel SDA is obtained. The developed hierarchical IO-SDA model would provide consistent results and need less computation effort compared with the traditional SDA model. The decomposition results of the steel plant suggest that the technology improvement and reduced steel final demand are two major reasons for declined total energy consumption. The technical improvements of blast furnaces, basic oxygen furnaces, the power plant and the by-products utilization level have contributed mostly in reducing energy consumption. A major retrofit of ancillary process units and solving fuel substitution problem in the sinter plant and blast furnace are important for further energy saving. Besides the empirical results, this work also discussed that why and how hierarchical SDA can be applied in a process-level decomposition analysis of aggregated indicators.展开更多
Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also...Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also put forward new requirements for the quality of steel structure bridges.However,in actual design,due to the influence of many fectors,some problems are inevitable,which will affect the integrity of the design.Therefore,the designer needs to fully grasp the possible design problems,and then take efiective measures to improve the integrity of the design scheme,so as to ensure the quality of the steel structure bridge and improves the safety of the steel structure bridge from the fundamentals.This paper mainly focuses on steel structure bridges,analyzed the current status of steel structure bridge types and their selection,and proposes the integrity design strategy of steel structure bridges.展开更多
A coupled dynamics computation model for metro vehicles, along with a steel-spring floating-slab track, is developed based on the theory of vehicle-track coupled dynamics. Using the developed model, the influences of ...A coupled dynamics computation model for metro vehicles, along with a steel-spring floating-slab track, is developed based on the theory of vehicle-track coupled dynamics. Using the developed model, the influences of the thickness, length and mass of floating-slab, spring rate and its arrangement space, running speed, etc. on the time and frequency domain characteristics of steel-spring fulcrum force are analyzed. The applicability of steel-spring floatingslab track is discussed through two integrated example cases of metro and buildings possessing distinct natural vibra- tion characteristics. It is concluded that, it is quite significant, in the optimization modular design of the parameters of steel-spring floating-slab track, to take the matching relationship of both the amplitude-frequency characteristics of steel-spring fulcrum force and natural vibration characteristics of integrated structures into comprehensive consideration. In this way the expensive steel-spring floating-slab track can be economically and efficiently utilized according to the site condition, and at the same time, the economic losses and bad social impact resulted from the resonance during usage of steel-spring floating-slab track can be avoided.展开更多
Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending o...Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending on the designer’s knowledge and philosophy.Integrated design is one type of design philosophy that takes an interdisciplinary and holistic approach.In civil engineering,structural design is such an activity for creating buildings and infrastructures.Recently,structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety,durability,serviceability,and sustainability.Consequently,integrated design in civil engineering has become more popular,useful,and important.Material-oriented integrated design and construction of structures(MIDCS)combine materials engineering and structural engineering in the design stage:it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction methodologies.This paper will explore real-world examples of MIDCS,including the realization of MIDCS in timber seismic-resistant structures,masonry arch structures,long-span steel bridges,prefabricated/on-site extruded light-weight steel structures,fiber-reinforced cementitious composites structures,and fiber-reinforced polymer bridge decks.Additionally,advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDCS can combine materials and structures.A unified strengthdurability design theory is also introduced,which is a human-centric,interdisciplinary,and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the infrastructure.Finally,this paper lays out future research directions for further development in the field.展开更多
文摘Pier-Pile integral structures provide construction works with many environmental and landscape advantages. For example, the space required to construct these structures is smaller than that of other bridges due to the footing being removed, meaning that it is not necessity to greatly change the surroundings of these bridges. While there are environmental and landscape advantages, there are also a few demerits for the overall land-scape designs, including demerits in the design of this proposed structure which consists of relatively slender parts. This proposed structure has already been constructed in areas where possibility of a severe earthquake is low. However, some problems that have yet to be examined are related to the use of this proposed structure in areas where earthquakes are frequent. Lacking detailed studies of its behavior during severe earthquakes, it is currently difficult to construct these structures in Japan. Consequently, it is necessary to investigate in detail limited performance about compression and bending moment, and earthquake- resistant performance of these structures in order to resolve these problems. In this paper, It was clarified the relationship between the rigidity of the ground and the effective buckling length by buckling analysis and elasto- plastic finite deformation analysis. Moreover, it was proposed a simplified formula using a proposed characteristic value β and several factors for analysis accuracy. A simplified formula would support to determine the effective buckling length to design the pier using the load-bearing capacity curve based on the slenderness ratio parameter.
基金Project(2012GK2025)supported by Science-Technology Plan Foundation of Hunan Province,ChinaProject(2013zzts039)supported by the Fundamental Research Funds for Central South University,China
文摘A hierarchical structural decomposition analysis(SDA) model has been developed based on process-level input-output(I-O) tables to analyze the drivers of energy consumption changes in an integrated steel plant during 2011-2013. By combining the principle of hierarchical decomposition into D&L method, a hierarchical decomposition model for multilevel SDA is obtained. The developed hierarchical IO-SDA model would provide consistent results and need less computation effort compared with the traditional SDA model. The decomposition results of the steel plant suggest that the technology improvement and reduced steel final demand are two major reasons for declined total energy consumption. The technical improvements of blast furnaces, basic oxygen furnaces, the power plant and the by-products utilization level have contributed mostly in reducing energy consumption. A major retrofit of ancillary process units and solving fuel substitution problem in the sinter plant and blast furnace are important for further energy saving. Besides the empirical results, this work also discussed that why and how hierarchical SDA can be applied in a process-level decomposition analysis of aggregated indicators.
文摘Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also put forward new requirements for the quality of steel structure bridges.However,in actual design,due to the influence of many fectors,some problems are inevitable,which will affect the integrity of the design.Therefore,the designer needs to fully grasp the possible design problems,and then take efiective measures to improve the integrity of the design scheme,so as to ensure the quality of the steel structure bridge and improves the safety of the steel structure bridge from the fundamentals.This paper mainly focuses on steel structure bridges,analyzed the current status of steel structure bridge types and their selection,and proposes the integrity design strategy of steel structure bridges.
基金supported by the Key Project of Science and Technology in an Action of Shanghai Scientific and Technological Innovation (No. 09231201600)the National Natural Science Foundation of China(No. 50823004)the Science and Technology Department of Sichuan Province
文摘A coupled dynamics computation model for metro vehicles, along with a steel-spring floating-slab track, is developed based on the theory of vehicle-track coupled dynamics. Using the developed model, the influences of the thickness, length and mass of floating-slab, spring rate and its arrangement space, running speed, etc. on the time and frequency domain characteristics of steel-spring fulcrum force are analyzed. The applicability of steel-spring floatingslab track is discussed through two integrated example cases of metro and buildings possessing distinct natural vibra- tion characteristics. It is concluded that, it is quite significant, in the optimization modular design of the parameters of steel-spring floating-slab track, to take the matching relationship of both the amplitude-frequency characteristics of steel-spring fulcrum force and natural vibration characteristics of integrated structures into comprehensive consideration. In this way the expensive steel-spring floating-slab track can be economically and efficiently utilized according to the site condition, and at the same time, the economic losses and bad social impact resulted from the resonance during usage of steel-spring floating-slab track can be avoided.
基金This work was supported by the Science and Technology Development Fund,Macao SAR(0083/2018/A2)Multi-Year Research Grant(MYRG2019-00135-IAPME)Research&Development Grant for Chair Professor(CPG2020-00002-IAPME).
文摘Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending on the designer’s knowledge and philosophy.Integrated design is one type of design philosophy that takes an interdisciplinary and holistic approach.In civil engineering,structural design is such an activity for creating buildings and infrastructures.Recently,structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety,durability,serviceability,and sustainability.Consequently,integrated design in civil engineering has become more popular,useful,and important.Material-oriented integrated design and construction of structures(MIDCS)combine materials engineering and structural engineering in the design stage:it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction methodologies.This paper will explore real-world examples of MIDCS,including the realization of MIDCS in timber seismic-resistant structures,masonry arch structures,long-span steel bridges,prefabricated/on-site extruded light-weight steel structures,fiber-reinforced cementitious composites structures,and fiber-reinforced polymer bridge decks.Additionally,advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDCS can combine materials and structures.A unified strengthdurability design theory is also introduced,which is a human-centric,interdisciplinary,and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the infrastructure.Finally,this paper lays out future research directions for further development in the field.
