In response to the increasing operation and maintenance pressure and efficiency requirements of urban rail transit, a comprehensive management and control platform based on digital twins and multisystem integration is constructed and implemented to achieve intensive and refined operation and maintenance management of subway stations and improve management efficiency and service levels. Through 3D scanning of existing lines, this paper focuses on the development and implementation of an integrated management and control platform based on digital twin technology and multisystem integration, enhancing management efficiency and service quality. Firstly, a digital twin model is constructed to represent the operation of urban rail systems. The study explores model lightweight technology and uses 3D rendering engines to render and optimize large models and large scenes. In addition, this paper studies multisource heterogeneous data fusion technology through data standardize processing to realize the processbased collection and storage of heterogeneous data of various professions. Furthermore, a comprehensive urban rail management and control platform is developed, integrating functional modules to meet the needs of various disciplines. This platform improves the execution efficiency of operation and maintenance tasks by 30%, increases the accuracy of equipment and facility status monitoring to 98%, and increases the success rate of preventive maintenance by 20%. The efficiency of cross-disciplinary data sharing and collaborative work is enhanced by over 60%, resulting in a shortened fault response time, significantly improved accuracy of equipment and facility status monitoring, and enhanced effectiveness of preventive maintenance.

To address the issue of not being able to provide an opencut receiving well at the receiving end of rectangular pipe jacking, this study analyzes the soil prereinforcement scheme used in the construction of rectangular pipejacking reception. It explores the appropriate structural type for the castinplace section of the abandoned shell and proposes a waterproofing scheme between the castinplace section of the abandoned shell, the precast pipe joints, and the hidden beams and columns of the station. t This study is based on the new entrance project of Jingjiang Road Station on Tianjin Metro Line 2. The processes, including the shutdown of the pipe jacking machine and grouting, are also optimized. Practical results show that the proposed scheme ensures the safe construction of the abandoned shell reception, with monitoring data indicating a maximum surface settlement of 12.12 mm. The key technology proposed in this paper are highly feasible and effective, offering a new design approach for similar projects, such as abandoned shell reception, where construction site limitations exist.

Monorail transportation systems currently face challenges such as relatively independent specialties, numerous workstation terminals, high usage, and elevated management and maintenance costs. Additionally, data interconnectivity between subsystems is lacking, making coordination and command difficult in the event of faults or accidents. This paper presents a comprehensive analysis and research on these issues, focusing on data control, subsystem business implementation, and operation and maintenance requirements. The paper elaborates on an architecture scheme for a deeply integrated monorail comprehensive operation and dispatch system based on a unified software/hardware platform and humanmachine interface across various professional subsystems. It explores the application of this scheme in different scenarios, including upgrading existing lines, constructing new lines, and achieving networklevel integration. The proposed system addresses the needs of data control and comprehensive intelligent operation and maintenance by integrating the architecture of center, station, and depot/parking lot system equipment, as well as integrating or interfacing various subsystems. This allows for monitoring and control of various professional system equipment on a unified platform. The analysis demonstrates that adopting a single track system with comprehensive operation scheduling significantly enhances system integration, simplifies job positions, and effectively reduces construction and operation costs. The comprehensive operation and dispatch system enables the interconnection and sharing of various professional resources, providing users with complete and rich information support within a unified platform during emergencies or equipment failures. Through intelligent linkage and other automatic control technologies, operational efficiency can be considerably improved. The integrated operation and dispatch system solution aligns with the development direction of integrated, simplified, and streamlined monorail transportation systems. It is expected to be the future trend for China’s monorail transportation operation and control systems.

In order to solve the problem that the traditional monitoring analysts in the field of urban rail transit have a high falsenegative rates and complex parameter adjustment of abnormal behaviors such as falling, fainting and fighting, making them difficult to apply efficiently to actual urban rail station monitoring scenarios, this paper proposes a human posture feature recognition framework based on skeleton pattern recognition, introducing the attitude estimation technology based on human skeleton. The Alpha Pose model is used to accurately estimate the posture of passengers, and combined with the Spatial Temporal Graph Convolutional Networks model, it achieves abnormal behavior recognition in the monitoring scenario of urban rail stations. By achieving 72.3 mAP on the COCO dataset and 82.1 mAP on the MPII dataset, the performance is improved by up to 17% compared to the OpenPose model, verifying the effectiveness and practicality of the model. The results show that the method proposed in this paper not only improves the recognition speed of passenger behavior but also has the ability to adapt to complex scenarios, providing a new technical solution for urban rail safety monitoring.

The control of micro deformation of adjacent buildings during the construction of deep foundation pits in weak strata is one of the challenges in the geotechnical field. Taking the construction project of subway deep foundation pit of adjacent buildings in soft ground in Hangzhou as an example, this paper introduced the micro deformation control technologies such as the reinforcement technology of underground continuous wall trough wall, sleeve valve pipe grouting reinforcement technology, servo steel support system, and the reinforcement and excavation technology of underground middle wall, and analyzed the deformation characteristics and the effect of micro deformation control technology in the construction of deep foundation pit of adjacent buildings in soft ground. The results indicate that the sleeve valve pipe grouting reinforcement technology reduces the impact of construction on the surrounding building group and suppresses its deformation; the deformation of the enclosure structure and surrounding deformation can be suppressed through slot wall reinforcement technology, and the quality of the enclosure structure has been improved; the servo steel support system effectively suppresses the deformation of the enclosure structure and reduces the impact of construction on the surrounding area; cross wall and block excavation technology suppresses building deformation and weakens the impact of spatiotemporal effects. In the end, the surrounding buildings of the deep foundation pit basically achieved the goal of "micro deformation”.

This study addresses the current lack of experience in network operations of urban express lines based on fully automated operation technology in China, as well as the lack of corresponding operational reference standards and comprehensive technical solutions. Through the study of relevant literature and empirical analysis of the operation schemes of Chongqing Suburban Railway Bitong Line and Urban Rail Express Line 27, this study investigates the network scheduling, train planning, and train organization of urban express lines based on fully automatic operation technology. This study proposes the integration scheme of personnel (except train dispatchers) in the network dispatching hall and the arrangement scheme of multiple lines in the form of grouping under the network operation conditions of urban express lines interconnection. The study also proposes the establishment process and principles of the train operation plan, the operation organization principles under normal and abnormal operation scenarios, and the crossline operation scenarios between fully automatic and nonfully automatic trains. Through research, we aim to achieve an interconnected and network operation technology solution that integrates resources and improves efficiency across the entire line network, which is conducive to achieving automatic crossline operation between urban express lines, improving service levels, and promoting the construction of smart urban rail transit.

Considering the problems of the difficult data collection, nonstandard models, and inaccurate data in the digitalization of existing buildings, the BIMbased digitalization method for existing rail transit projects was studied and proposed, according to the characteristics of rail transit projects. First, based on data requirements of the operation and maintenance management, an overall framework for BIM digitalization and scenario applications in existing rail transit projects was developed. Second, the technical guideline for BIM modeling and delivery was studied and established, and a BIM component standard library was developed to standardize the creation of BIM models of existing rail transit projects. Third, according to the onsite data collection situation, different methods were adopted to create BIM models of existing rail transit projects. When the drawings were complete, models could be created based on the drawings. When some drawings were missing, the BIM model creation method based on the on-site images and point cloud data was studied through component feature recognition and matching component units in the BIM component standard library. Finally, to ensure the quality of BIM models, a compliance checking tool with embedded BIM standard specifications was developed for automatic model verification. Additionally, on-site inspection was conducted for various professional BIM models. The BIM construction of existing operating lines in Shenzhen Metro is being carried out, accumulating BIM-based digital assets, which provides reference for the BIM construction of existing operating lines in other cities.

The urban rail transit projects in China have adopted overhead contact system power supply and dedicated rail return current scheme to solve the problem of stray current leakage. However, there are currently no applications of dedicated rail return under contact rail power supply systems in China. This article proposes four dedicated rail return current schemes based on the contact rail power supply systems. It analyzes and evaluates these four schemes through quantitative and qualitative methods, considering aspects such as equipment impact, vehicle current return, networked operation of lines, power supply system protection, safety, and costeffectiveness. It discusses the feasibility, advantages, and disadvantages of each scheme, and ultimately recommends a dedicated rail return scheme based on the contact rail power supply system. Finally, it proposes a recommended dedicated rail return scheme based on the contact rail power supply system, and summarizes the impact of dedicated rail return on other disciplines.

Aiming at the problem of excessive settlement of the station caused by the new tunnel close to the existing station, relying on the project of Xi'an Metro Line 8 close to the Convention and Exhibition Center Station of Line 2, the numerical simulation and onsite monitoring are used to analyze the control effect of various control measures on the deformation of the existing station during the construction of the underpass. The recommended values of construction parameters of the tunnel in the loess area are given. The results show that: (1) The construction method and excavation footage have obvious effect on the deformation control of the station when it is close to the underpass. After the construction method is adjusted from the upper and lower step method to the onsite CRD method, the maximum settlement of the station is reduced by 50%. After the excavation footage is adjusted from 1.5 m to 0.5 m, the maximum settlement of the station is reduced by 30%. (2) The staggered distance between the upper and lower pilot tunnels and the erection of temporary steel support have a weak effect on the deformation control of the station, which can be appropriately adjusted according to the engineering geology and onsite monitoring. (3) Based on the project, the construction scheme of onsite CRD method +0.5 m excavation footage +5 m singleside cavern upper and lower guide hole staggered distance +5 m spacing temporary steel support is adopted. The onsite monitoring data are basically the same as the deformation law obtained by numerical calculation. The maximum settlement of the station side wall, ballast bed and track is 3.76, 2.91, 2.51 mm respectively, and the maximum differential settlement at the deformation joint is 3.54 mm, which meets the requirements of the station deformation control standard.

With reference to internationally recognized statistical, urban rail transit is categorized into three major types, namely metro, light rail and tram. This analysis reviews the current status of urban rail transit operations worldwide. The findings show that by the end of 2024, 562 cities in 79 countries and regions around the world have opened urban rail transit systems, with a total length of more than 44,730.14 km. Subways, light rails, and streetcars each account for 51.24%, 10.43% and 38.34%, respectively. As of December 31, 2024, 65 cities in China (including Hong Kong, Macao and Taiwan) have operational rail transit systems, with an operating length of 12,844.57 km, of which the operating length in Chinese mainland is 12,168.77 km. In 2023, the metros of 188 cities in 59 countries around the world transported a total of 713.78 million passengers, with an average daily load of 0.85 million trips per kilometer. In China (including Hong Kong, Macao, and Taiwan), metro systems carried 31.81 billion trips annually. China's urban rail transit continues to grow steadily, with the size of its network and passenger volume ranking first globally. Additionally, 233 cities in 54 countries and regions have opened suburban railways, totaling 64,195.23 km, with 21 cities in China (including Hong Kong, Macao, and Taiwan) operating 2,974.40 km of suburban railways. An analysis of the scale and development of rail networks in key countries suggests that the construction of suburban railways in China, as well as the interconnection of different networks, holds significant potential.