As a novel form of railway transportation, maglev transportation has the advantages of a better curve negotiation ability and grade ability and lower noise and vibration than traditional urban wheel–rail transportation. Thus, it is suitable for use in urban public transportation. However, the levitation of the widely utilized electromagnet suspension (EMS) system relies on continuously active suspension force adjustment, which gives it vehicle–track-coupled vibration characteristics different to those of the traditional wheel–track transportation system. Despite many research studies focusing on maglev vehicle–track coupling vibration, the environmental vibration influences associated with the running of maglev trains are still unclear. When the vibration propagates to the surroundings beyond certain thresholds, it may lead to various vibration serviceability problems. Practical test results on the environmental vibration induced by maglev transportation are still not enough to generate convincing vibration propagation and attenuation laws. In this research, a series of in situ tests were carried out around the Shanghai maglev line; the results show that the viaduct bridge is helpful in reducing environmental vibration, and an empirical formula was proposed to predict the effect of viaduct column height. Due to the ground wave superposition, a vibration-amplifying zone was also found about 10 m away from the maglev line, in which the vibration magnitude was strong enough to be perceived by the surrounding occupants.
Research on low-speed maglev technology has been conducted for more than thirty years in China. After years of efforts to bring it into operation, decision-makers of Beijing's government made up their minds to initiate the building of the S1 line at the end of last year. The feasibility study of Urban Transit Line 8, adopting this system in Shenzhen city, is also near completion. Undoubtedly, a low-speed maglev system is very promising for its lower noise, better climbing capacity and ability to negotiate smaller radius curves as compared with a wheel-rail system. However, there are still many challenges with regard to using this system in densely built urban areas due to the lack of space for system arrangement. Based on experiences from the Tobu Kyuryo low-speed line, the Shanghai high-speed maglev line and low-speed maglev test line, this work summarized problems to be solved for a low-speed maglev system to build a more "compact" system in such areas. This study was concerned with continuing system optimization - including the selection of guideway structures, the strategy for vehicle stopping, and inspection and maintenance which determine the configuration of facilities - in order to increase the efficiency of space and land use.
The National Maglev Technology R&D Center (NMTC) has been doing research on low-speed maglev technologies since 2005. The Shanghai low-speed maglev test line was built in July 2006 with a total length of 2.0 kilometers. During the layout of the test line, situations that may arise in engineering practice were taken into account. For the guideway system, different types of structures for the main line and the vehicle maintenance line, of different spans, were produced and erected. From 2006 to 2010, numerous tests have been systematically conducted on the line, covering all sub-systems. According to experiences from the Shanghai high-speed maglev line, dynamic response of the guideway structure may have a great influence on the stable running of a maglev vehicle. During these tests, dynamic responses of different types of girders and track skeletons wee recorded and analyzed, including accelerations, displacements and stresses. The responses of different parts of the guideway switch were also taken in order to make evaluations and find its weakness to guide further optimization. Through these analyses, some instructive suggestions for the design of guideway structures were acquired.
19 December 2018 in Transportation systems and technology
Background: Shanghai Maglev Demonstration Line is the only commercial high-speed maglev train line in the world, which has multiple functions such as transportation, exhibition, tourism and sightseeing. Besides, Shanghai Maglev Demonstration Line has been in operation for 15 years, and has been operating safely and punctually. Maglev protected area are located within 30 meters of the left and right sides of the Shanghai Maglev Demonstration Line and unrelated persons are not allowed to enter the area. When there were external construction invading the protected area, it is neccessary to do the comprehensive technical monitoring and protection. Without similar project to refer to, Metro Line 13 traversing Shanghai Maglev Line was a big challenge. Therefore, effective measures should be taken to do the comprehensive technical monitoring. Finding the relation between the maglev deformation and shield construction parameters was an important part of the monitoring. Aim: This thesis aimed at finding the relation between the maglev deformation and shield construction parameters and controlling the maglev deformation in the crossing of Metro Line 13, thus guiding the shield construction. Methods: This thesis calculated the gray relation between the maglev deformation and shield construction parameters from the cause of deformation of the maglev by the gray relation analysis. Results: The construction parameters optimization and the sensitivity control are carried out. Meanwhile, combined with the measured results of deformation monitoring, the multi means parallel monitoring data are analyzed synthetically and the data are checked, and the construction parameters are adjusted reasonably to make the pier column deformation in the controllable permissible range, having ensured the safe operation of the maglev. Conclusion: The calculation results has provided a reference for realizing active control on the influence of shield construction on the maglev and has remedied the defect that could only use deformation monitoring but could not control the deformation actively in the past work. The gray relational analysis has a certain effect on controlling the influence of shield construction on surrounding structures and has certain reference significance for subsequent similar projects.
6 August 2022 in International Journal of Steel Structures