The synchronous construction of the secondary lining during the boring of large-diameter shield faces challenges such as the design of the lining jumbo,the high requirements on the performance for the lining jumbo,the...The synchronous construction of the secondary lining during the boring of large-diameter shield faces challenges such as the design of the lining jumbo,the high requirements on the performance for the lining jumbo,the organization of the construction activities in the small and confined area,the horizontal transportation for shield boring and high safety management requirements.A super-long invert lining construction jumbo,as well as the matching California switch,is developed,which provides solution for the confliction between the invert lining construction and the horizontal transportation.The procedure and method for the synchronous operation of the shield boring and the secondary lining are developed by referring to the synchronous construction of the secondary lining during the boring of the TBMs in hard rocks.Due to the adoption of the synchronous operation of the shield boring and the secondary lining,the construction period is shortened and the construction cost is reduced.The paper can provide reference for the synchronous construction of the secondary lining in similar projects in the future.展开更多
At the beginning of this century, with the development of materials industry, new heat-resistant conductors appeared, mainly including rod-shaped carbon fiber composite core conductor (ACCC) and stranded carbon fiber ...At the beginning of this century, with the development of materials industry, new heat-resistant conductors appeared, mainly including rod-shaped carbon fiber composite core conductor (ACCC) and stranded carbon fiber composite core conductor (ACMCC). At present, China can independently produce 7-core, 19-core, 37-core and 61-core stranded carbon fiber core, and can cooperate with aluminum wires to form stranded carbon fiber overhead conductors of 95/20-2000/400 mm in various specifications. It can be used for new construction, capacity expansion and reconstruction, extra-large span, extra-high voltage, extra-large cross-section and other lines. Stranded carbon fiber conductor (ACMCC) is composed of stranded carbon fiber core and aluminum/aluminum alloy conductor. The core of carbon fiber is composed of a plurality of T700 and T800 carbon fiber tows, which are impregnated with high-temperature resistant epoxy resin and wrapped with high-temperature resistant fibers to form strands;then several strands are twisted into 7-core, 19-core, 37-core and 61-core carbon fiber cores, which are cured at high temperature. Stranded carbon fiber wire has the advantages of light weight, high breaking force, high temperature resistance, high elastic modulus and low linear expansion coefficient. When the conductor cross-sectional area is the same, the maximum cross-sectional flow is 2.6 times of that of ordinary steel-reinforced aluminum stranded wire. When the cross-sectional area of the conductor is the same, taking the sag at 160℃ as an example, it is 0.7 times that of the heat-resistant road alloy conductor (the smaller the sag, the better). When the cross-sectional area of the wire is the same, its weight is 0.8 times that of other wires.展开更多
With the development of China's society, the development of power line engineering is also accelerating, and its application scope is more extensive. It also gradually involves many fields. With the update and ite...With the development of China's society, the development of power line engineering is also accelerating, and its application scope is more extensive. It also gradually involves many fields. With the update and iteration of related technologies, many problems are constantly exposed, especially safety management. In the process of electric power construction, enterprises must strengthen the management of electric power line construction to ensure the smooth development of the whole electric power project. In this paper, the problems existing in power line construction and the related contents of safety management countermeasures are discussed, hoping to provide some effective references.展开更多
With the development of economy and the improvement of science and technology in China, advanced construction technology such as modern seamless rail has gradually become one of the main development directions of rail...With the development of economy and the improvement of science and technology in China, advanced construction technology such as modern seamless rail has gradually become one of the main development directions of railway engineering construction in China. This paper summarizes the replacement technology of railway jointless track, analyzes and studies its corresponding replacement mode and locking technology according to relevant technical regulations, summarizes a complete set of technology and quality control standards, and completes the replacement of jointless track with quality and quantity, which has accumulated valuable experience for the replacement construction of jointless track of heavy haul railway and can also provide technical reference for similar heavy haul railway laying projects.展开更多
Model tests and numerical calculations were adopted based on the New Yuanliangshan tunnel project to investigate the water pressure resistance of lining construction joints in high-pressure and water-rich karst tunnel...Model tests and numerical calculations were adopted based on the New Yuanliangshan tunnel project to investigate the water pressure resistance of lining construction joints in high-pressure and water-rich karst tunnels.A large-scale model test was designed and conducted,innovatively transforming the external water pressure of the lining construction joint into internal water pressure.The effects of the embedded position and waterstop type on the water pressure resistance of the construction joint were analyzed,and the reliability of the model test was verified via numerical calculations.The results show that using waterstops can significantly improve the water pressure resistance of lining construction joints.The water pressure resistance of the lining construction joint is positively correlated with the lining thickness and embedded depth of the waterstop.In addition,the type of waterstop significantly influences the water pressure resistance of lining construction joints.The test results show that the water pressure resistance of the embedded transverse reinforced waterstop is similar to that of the steel plate waterstop,and both have more advantages than the rubber waterstop.The water pressure resistance of the construction joint determined via numerical calculations is similar to the model test results,indicating that the model test results have high accuracy and reliability.This study provides a reference for similar projects and has wide applications.展开更多
The first UHV experimental line section of 1000 kV class in China, situated at the outdoor test yard of Wuhan High Voltage Research Institute under the Ministry of Electric Power has been built just before July 1st, 1...The first UHV experimental line section of 1000 kV class in China, situated at the outdoor test yard of Wuhan High Voltage Research Institute under the Ministry of Electric Power has been built just before July 1st, 1996. This experimental line section is 200 m long with 3 phase, 8展开更多
文摘The synchronous construction of the secondary lining during the boring of large-diameter shield faces challenges such as the design of the lining jumbo,the high requirements on the performance for the lining jumbo,the organization of the construction activities in the small and confined area,the horizontal transportation for shield boring and high safety management requirements.A super-long invert lining construction jumbo,as well as the matching California switch,is developed,which provides solution for the confliction between the invert lining construction and the horizontal transportation.The procedure and method for the synchronous operation of the shield boring and the secondary lining are developed by referring to the synchronous construction of the secondary lining during the boring of the TBMs in hard rocks.Due to the adoption of the synchronous operation of the shield boring and the secondary lining,the construction period is shortened and the construction cost is reduced.The paper can provide reference for the synchronous construction of the secondary lining in similar projects in the future.
文摘At the beginning of this century, with the development of materials industry, new heat-resistant conductors appeared, mainly including rod-shaped carbon fiber composite core conductor (ACCC) and stranded carbon fiber composite core conductor (ACMCC). At present, China can independently produce 7-core, 19-core, 37-core and 61-core stranded carbon fiber core, and can cooperate with aluminum wires to form stranded carbon fiber overhead conductors of 95/20-2000/400 mm in various specifications. It can be used for new construction, capacity expansion and reconstruction, extra-large span, extra-high voltage, extra-large cross-section and other lines. Stranded carbon fiber conductor (ACMCC) is composed of stranded carbon fiber core and aluminum/aluminum alloy conductor. The core of carbon fiber is composed of a plurality of T700 and T800 carbon fiber tows, which are impregnated with high-temperature resistant epoxy resin and wrapped with high-temperature resistant fibers to form strands;then several strands are twisted into 7-core, 19-core, 37-core and 61-core carbon fiber cores, which are cured at high temperature. Stranded carbon fiber wire has the advantages of light weight, high breaking force, high temperature resistance, high elastic modulus and low linear expansion coefficient. When the conductor cross-sectional area is the same, the maximum cross-sectional flow is 2.6 times of that of ordinary steel-reinforced aluminum stranded wire. When the cross-sectional area of the conductor is the same, taking the sag at 160℃ as an example, it is 0.7 times that of the heat-resistant road alloy conductor (the smaller the sag, the better). When the cross-sectional area of the wire is the same, its weight is 0.8 times that of other wires.
文摘With the development of China's society, the development of power line engineering is also accelerating, and its application scope is more extensive. It also gradually involves many fields. With the update and iteration of related technologies, many problems are constantly exposed, especially safety management. In the process of electric power construction, enterprises must strengthen the management of electric power line construction to ensure the smooth development of the whole electric power project. In this paper, the problems existing in power line construction and the related contents of safety management countermeasures are discussed, hoping to provide some effective references.
文摘With the development of economy and the improvement of science and technology in China, advanced construction technology such as modern seamless rail has gradually become one of the main development directions of railway engineering construction in China. This paper summarizes the replacement technology of railway jointless track, analyzes and studies its corresponding replacement mode and locking technology according to relevant technical regulations, summarizes a complete set of technology and quality control standards, and completes the replacement of jointless track with quality and quantity, which has accumulated valuable experience for the replacement construction of jointless track of heavy haul railway and can also provide technical reference for similar heavy haul railway laying projects.
基金the General Program of the National Natural Science Foundation of China(Grant No.51878037).
文摘Model tests and numerical calculations were adopted based on the New Yuanliangshan tunnel project to investigate the water pressure resistance of lining construction joints in high-pressure and water-rich karst tunnels.A large-scale model test was designed and conducted,innovatively transforming the external water pressure of the lining construction joint into internal water pressure.The effects of the embedded position and waterstop type on the water pressure resistance of the construction joint were analyzed,and the reliability of the model test was verified via numerical calculations.The results show that using waterstops can significantly improve the water pressure resistance of lining construction joints.The water pressure resistance of the lining construction joint is positively correlated with the lining thickness and embedded depth of the waterstop.In addition,the type of waterstop significantly influences the water pressure resistance of lining construction joints.The test results show that the water pressure resistance of the embedded transverse reinforced waterstop is similar to that of the steel plate waterstop,and both have more advantages than the rubber waterstop.The water pressure resistance of the construction joint determined via numerical calculations is similar to the model test results,indicating that the model test results have high accuracy and reliability.This study provides a reference for similar projects and has wide applications.
文摘The first UHV experimental line section of 1000 kV class in China, situated at the outdoor test yard of Wuhan High Voltage Research Institute under the Ministry of Electric Power has been built just before July 1st, 1996. This experimental line section is 200 m long with 3 phase, 8
