The dynamic interaction between maglev vehicle and three-span continuous guideway is discussed. With the consideration of control system, the dynamic interaction model has been developed. Numerical simulation has been...The dynamic interaction between maglev vehicle and three-span continuous guideway is discussed. With the consideration of control system, the dynamic interaction model has been developed. Numerical simulation has been performed to study dynamic characteristics of the guideway. The results show that bending rigidity, vehicle speed, span ratio and primary frequency all have important influences on the dynamic characteristics of the guideway and there is no distinct trend towards resonance vibration when fl/（v/l） equals 1.0. The definite way is to control impact coefficient and acceleration of the guideway. The conclusions can serve the design of high-speed maglev three-span continuous guideway.展开更多
Small H-beams such as the No.14-20 I-steel can be inserted into soil-cement retaining walls to form small H-beam soil-cement compound walls, functioning both as a retaining wall and a cutoff wall for braced structure ...Small H-beams such as the No.14-20 I-steel can be inserted into soil-cement retaining walls to form small H-beam soil-cement compound walls, functioning both as a retaining wall and a cutoff wall for braced structure excavations. Being different from the mixed soil-cement wall （SMW）, the interaction between soil-cement and small H-steel is very good. We have carried out a series of bending experiments on small H-beams in soil-cement model compound beams to study the mechanism of interactions. The results show that the interaction between H-beams and soil-cement is very good, whether the H-beam is single or double. Joint forms of double H-beams at one end have little effect on both the contribution coefficient and on ultimate deflection before cracking. But after cracking, the joint forms greatly affect the contribution coefficient. We conclude that the rigid joint girder for double H-beams is a better choice in oractice.展开更多
Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual...Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual prestressing forces from the designed values during tension structure construction or service period, and further to threaten the safety and reliability of the structure. Aiming at relatively large errors of the prestressing force of strings in a tension structure construction or service period, this paper proposes a new finite element method (FEM), the "tensile force correction calculation method". Based on the measured prestressing forces of the strings, this new method applies the structure from the zero prestressing force status approach to the measured prestressing force status for the first phase, and from the measured prestressing force status approach to the designed prestressing force status for the second phase. The construction tensile force correction value for each string can be obtained by multi-iteration with FEM. Using the results of calculation, the strings’ tensile force correction by group and in batch will be methodic, simple and accurate. This new calculation method can be applied to the prestressed correction construction simulation analysis for tension structures.展开更多
In this paper, we conduct research on the present situation and improvement strategy of the water conservancy project construction quality management based on quality efficiency equilibrium theory. Water conservancy e...In this paper, we conduct research on the present situation and improvement strategy of the water conservancy project construction quality management based on quality efficiency equilibrium theory. Water conservancy engineering construction enterprises should refer to oneself circumstance, and the characteristics of the water conservancy project, determine the quality objectives of specific quality assurance plan and the related measures, clear implementation content, methods and effects. Strictly control the factors influencing the water conservancy engineering quality of many aspects, in the process of the water conservancy project construction, to establish a meet the requirements of the technical process and quality standards, operation procedures. Establish the strict appraisal system, continuous improvement and improve the level of construction technique and technology. Establish strict quality assurance system and quality responsibility system, each division, subdivisional work will comprehensively implement in place management to ensure the engineering quality.展开更多
Some new innovative constructions and technologies for improvement of port structures are worked out and discussed. The aims of innovations are to increase structures＇ reliability, to decrease cost of construction an...Some new innovative constructions and technologies for improvement of port structures are worked out and discussed. The aims of innovations are to increase structures＇ reliability, to decrease cost of construction and maintenance, to simplify technology and cost of building. For these purposes either some main bearing elements or structures in whole are modified or improved. In particular different improved waterfront constructions as well as retaining walls and coastal protection （gravity, piled, sheet piling, etc.） for use in various soil conditions are outlined. One of them incorporates trapezoidal blocks forming columns, each block in the column contacts the others either with smaller or larger bases. Another design incorporates blocks that are constructed with holes ran through the centres of gravity of the blocks. Rigid cylinder element running through the holes of several adjacent blocks allows them to be joined forming large size units, The structure consisting of wedge form retaining wall is original but simple to construct, Some new designs based on perfection of sheet-piling walls （sheet piles with curvilinear cross-section having a form of semi-rings） are proposed for different applications. Proposals on modernization of some traditional structures and technologies are discussed.展开更多
The present paper analyses the possibilities of using modern technology and technical engineering in conservation practices. Some examples of heritage abuse are given alongside some innovative ways of presenting relic...The present paper analyses the possibilities of using modern technology and technical engineering in conservation practices. Some examples of heritage abuse are given alongside some innovative ways of presenting relics of the past to society. Methodology consists in the scrutinizing of chosen examples, selecting conclusions and a synthetic presentation of research results. The aim is proper protection of historic architectural resources through documentation and dissemination of knowledge. First part is concerned to rejection of old aesthetics values and implementing a new one on example of Brussels＇ House of the People （the largest work by Victor Horta that opened on 1899 and demolished in 1965 despite a protest of architects） and ridiculous renovation in Krynica, Poland. In second part, it presents tree examples of successful implementation of innovative techniques and technologies as the Pauline fathers realizations of renovation sacred architecture （churches, cloisters）, also valuable digital projects of the reconstruction of the vaults and realization of underground Museum in Krakow, Poland （the outstanding creation of the atmosphere of virtual historic reality by the latest audio-visual techniques）.展开更多
The paper introduces automotive safety cost formula, which defines the concept of private costs, technology costs and social costs and analyzes the impact of economic externalities in individual purchase decisions on ...The paper introduces automotive safety cost formula, which defines the concept of private costs, technology costs and social costs and analyzes the impact of economic externalities in individual purchase decisions on urban traffic safety in the private costs and discusses the concept of hard and soft technology and its function to improve vehicle safety. Take people, vehicles and the environment as the main line and points out the promoting role of the relevant state departments, policy, research institutions and transportation infrastructure in the social cost for the entire transportation system security. Finally, about the security of car crash in low speed on urban roads, the paper gives some recommendations as for private costs, technology costs and social costs factor.展开更多
Shield machine is the major technical equipment badly in need in national infrastructure construction. The service conditions of shield machine are extremely complex. The driving interface load fluctuation caused by g...Shield machine is the major technical equipment badly in need in national infrastructure construction. The service conditions of shield machine are extremely complex. The driving interface load fluctuation caused by geological environment changes and multi field coupling of stress field may lead into imbalance of redundant drive motors output torque in main driving system. Therefore, the shield machine driving synchronous control is one of the key technologies of shield machine. This paper is in view of the shield machine main driving synchronous control, achieving the system＇s adaptive load sharing. From the point of view of cutterhead load changes, nonlinear factors of mechanical transmission mechanism and the control system synchronization performance, the authors analyze the load sharing performance of shield machine main drive system in the event of load mutation. The paper proposes a data-driven synchronized control method applicable to the main drive system. The effectiveness of the method is verified through simulation and experimental methods. The new method can make the system synchronization error greatly reduced, thus it can effectively adapt to load mutation, and reduce shaft broken accident.展开更多
This paper put forward the structure and construction process of three-dimensional visualization of hydroelectric construction system model based on GIS and 3D visualization platform. The paper first describes the 3D ...This paper put forward the structure and construction process of three-dimensional visualization of hydroelectric construction system model based on GIS and 3D visualization platform. The paper first describes the 3D visualization based on GIS, then discusses the method of constructing 3D visual digital model, and then introduces the terrain digital technology, feature modeling technology. Finally, the technical route shows that this method has good practicability.展开更多
基金Project (No. 2005AA505440) supported by the Hi-Tech Researchand Development Program (863) of China
文摘The dynamic interaction between maglev vehicle and three-span continuous guideway is discussed. With the consideration of control system, the dynamic interaction model has been developed. Numerical simulation has been performed to study dynamic characteristics of the guideway. The results show that bending rigidity, vehicle speed, span ratio and primary frequency all have important influences on the dynamic characteristics of the guideway and there is no distinct trend towards resonance vibration when fl/（v/l） equals 1.0. The definite way is to control impact coefficient and acceleration of the guideway. The conclusions can serve the design of high-speed maglev three-span continuous guideway.
文摘Small H-beams such as the No.14-20 I-steel can be inserted into soil-cement retaining walls to form small H-beam soil-cement compound walls, functioning both as a retaining wall and a cutoff wall for braced structure excavations. Being different from the mixed soil-cement wall （SMW）, the interaction between soil-cement and small H-steel is very good. We have carried out a series of bending experiments on small H-beams in soil-cement model compound beams to study the mechanism of interactions. The results show that the interaction between H-beams and soil-cement is very good, whether the H-beam is single or double. Joint forms of double H-beams at one end have little effect on both the contribution coefficient and on ultimate deflection before cracking. But after cracking, the joint forms greatly affect the contribution coefficient. We conclude that the rigid joint girder for double H-beams is a better choice in oractice.
基金Project (No. 50678157) supported by the National Natural ScienceFoundation of China
文摘Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual prestressing forces from the designed values during tension structure construction or service period, and further to threaten the safety and reliability of the structure. Aiming at relatively large errors of the prestressing force of strings in a tension structure construction or service period, this paper proposes a new finite element method (FEM), the "tensile force correction calculation method". Based on the measured prestressing forces of the strings, this new method applies the structure from the zero prestressing force status approach to the measured prestressing force status for the first phase, and from the measured prestressing force status approach to the designed prestressing force status for the second phase. The construction tensile force correction value for each string can be obtained by multi-iteration with FEM. Using the results of calculation, the strings’ tensile force correction by group and in batch will be methodic, simple and accurate. This new calculation method can be applied to the prestressed correction construction simulation analysis for tension structures.
文摘In this paper, we conduct research on the present situation and improvement strategy of the water conservancy project construction quality management based on quality efficiency equilibrium theory. Water conservancy engineering construction enterprises should refer to oneself circumstance, and the characteristics of the water conservancy project, determine the quality objectives of specific quality assurance plan and the related measures, clear implementation content, methods and effects. Strictly control the factors influencing the water conservancy engineering quality of many aspects, in the process of the water conservancy project construction, to establish a meet the requirements of the technical process and quality standards, operation procedures. Establish the strict appraisal system, continuous improvement and improve the level of construction technique and technology. Establish strict quality assurance system and quality responsibility system, each division, subdivisional work will comprehensively implement in place management to ensure the engineering quality.
文摘Some new innovative constructions and technologies for improvement of port structures are worked out and discussed. The aims of innovations are to increase structures＇ reliability, to decrease cost of construction and maintenance, to simplify technology and cost of building. For these purposes either some main bearing elements or structures in whole are modified or improved. In particular different improved waterfront constructions as well as retaining walls and coastal protection （gravity, piled, sheet piling, etc.） for use in various soil conditions are outlined. One of them incorporates trapezoidal blocks forming columns, each block in the column contacts the others either with smaller or larger bases. Another design incorporates blocks that are constructed with holes ran through the centres of gravity of the blocks. Rigid cylinder element running through the holes of several adjacent blocks allows them to be joined forming large size units, The structure consisting of wedge form retaining wall is original but simple to construct, Some new designs based on perfection of sheet-piling walls （sheet piles with curvilinear cross-section having a form of semi-rings） are proposed for different applications. Proposals on modernization of some traditional structures and technologies are discussed.
文摘The present paper analyses the possibilities of using modern technology and technical engineering in conservation practices. Some examples of heritage abuse are given alongside some innovative ways of presenting relics of the past to society. Methodology consists in the scrutinizing of chosen examples, selecting conclusions and a synthetic presentation of research results. The aim is proper protection of historic architectural resources through documentation and dissemination of knowledge. First part is concerned to rejection of old aesthetics values and implementing a new one on example of Brussels＇ House of the People （the largest work by Victor Horta that opened on 1899 and demolished in 1965 despite a protest of architects） and ridiculous renovation in Krynica, Poland. In second part, it presents tree examples of successful implementation of innovative techniques and technologies as the Pauline fathers realizations of renovation sacred architecture （churches, cloisters）, also valuable digital projects of the reconstruction of the vaults and realization of underground Museum in Krakow, Poland （the outstanding creation of the atmosphere of virtual historic reality by the latest audio-visual techniques）.
文摘The paper introduces automotive safety cost formula, which defines the concept of private costs, technology costs and social costs and analyzes the impact of economic externalities in individual purchase decisions on urban traffic safety in the private costs and discusses the concept of hard and soft technology and its function to improve vehicle safety. Take people, vehicles and the environment as the main line and points out the promoting role of the relevant state departments, policy, research institutions and transportation infrastructure in the social cost for the entire transportation system security. Finally, about the security of car crash in low speed on urban roads, the paper gives some recommendations as for private costs, technology costs and social costs factor.
文摘Shield machine is the major technical equipment badly in need in national infrastructure construction. The service conditions of shield machine are extremely complex. The driving interface load fluctuation caused by geological environment changes and multi field coupling of stress field may lead into imbalance of redundant drive motors output torque in main driving system. Therefore, the shield machine driving synchronous control is one of the key technologies of shield machine. This paper is in view of the shield machine main driving synchronous control, achieving the system＇s adaptive load sharing. From the point of view of cutterhead load changes, nonlinear factors of mechanical transmission mechanism and the control system synchronization performance, the authors analyze the load sharing performance of shield machine main drive system in the event of load mutation. The paper proposes a data-driven synchronized control method applicable to the main drive system. The effectiveness of the method is verified through simulation and experimental methods. The new method can make the system synchronization error greatly reduced, thus it can effectively adapt to load mutation, and reduce shaft broken accident.
文摘This paper put forward the structure and construction process of three-dimensional visualization of hydroelectric construction system model based on GIS and 3D visualization platform. The paper first describes the 3D visualization based on GIS, then discusses the method of constructing 3D visual digital model, and then introduces the terrain digital technology, feature modeling technology. Finally, the technical route shows that this method has good practicability.
