Addressing the critical issue of subway structure leakage in Beijing due to rising groundwater levels, this study focuses on the development of an effective management framework. The work presents a comprehensive prevention and control technology system tailored for the Beijing subway, encompassing risk identification, assessment, and mitigation strategies. The investigation begins with pinpointing the diverse factors that contribute to leakage and proceeds to evaluate the risks through both qualitative and quantitative approaches, which apply to different segments and stations within the subway system. Risk levels ranging from A through D have been devised to facilitate targeted emergency and routine leakage management protocols. The resultant strategies accommodate both urgent responses and standard leakage rectification processes. The findings of this research aim to serve as a theoretical and technical groundwork for the management of similar urban subway structures.

To explore the optimal scheme for the construction and upgrading of the big data platform in the urban rail transit industry, this study takes the urban rail big data platform as the research object. Our study starts from the development process of the urban rail big data platform, sorts out the three stages of the development of the urban rail big data platform and analyzes the technology and advantages and disadvantages of the big data platform at each stage. Then it focuses on summarizing the advantages of "Data lake and Warehouse integration, stream processing and batch processing integration, OLTP+OLAP, multiple loads" and other advantages of the "Data Lakehouse" big data technology in the current stage, and studies the key points of the architecture upgrade and transformation design of the big data platform based on this technology. The technology was verified in the upgradation and transformation of the big data platform of the Beijing Metro Data Center. The application shows that the "Data lakehouse" big data platform technology combines the advantages of low cost of data lake and high performance of data warehouse, solves the shortcomings of the original big data platform in performance, capacity and multipurpose support, and provides new solutions for the construction and upgradation of big data platforms in the urban rail industry.

Renovating existing lines is a key longterm task for achieving highquality and sustainable development of urban rail transit in China. Technical standards are essential for initiating, designing, and implementing renovation projects. This paper reviews the current technical standard system for urban rail transit and examines the suitability of existing standards for each stage of the renovation process. To address the issues of incomplete coverage, low applicability, and poor relevance of existing standards, we propose two approaches and schemes for developing a new technical standard system for renovating urban rail transit lines, along with the principles for constructing and formulating the standards. We focus on the technical standards for renovation, including the requirements for renovation determination, design, construction, acceptance, safety assessment, and postevaluation.

Urban rail transit in China has entered a new stage of transforming from "incremental expansion" to "stock optimization". This requires renovating existing lines, which poses a huge demand for funds and a high standard for longterm sustainability. Therefore, it is important to develop an investment and financing mechanism that matches the renovation needs and ensures the highquality development of urban rail transit. However, there is a lack of comprehensive and unified guidance for different types of renovation projects and various stakeholders. There is also an urgent need for theoretical research to support the innovation of investment and financing modes. This paper analyzes the experiences of typical cases in London, Japan, Beijing, Shanghai, Shenzhen, and Tianjin. Based on the economic, cyclical, and multibody characteristics of the projects, this paper proposes a grading and classification system for investment and financing, and constructs a mechanism that integrates financial subsidies and incentives with the stock of assets and new investment. This study can provide a reference and basis for improving the top-level design of renovation projects and forming a multi-principal synergistic investment and financing mechanism system for the medium and long term.

To evaluate the vibration reduction effect of urban express, similar sections with essentially the same line conditions were studied. Different vibration reduction measures and corresponding common overall track bed sections were tested onsite to study the vibration reduction effect of urban express vibration reduction measures. Through the time domain, frequency domain, and onethird octave analysis of the measured data, the vibration reduction measures and maximum Zvibration level (VLZmax) of the ordinary section of the tunnel wall were obtained, and the vibration reduction effects of different vibration reduction measures were compared. The vibration acceleration of the tunnel wall at the measuring point and the ground vibration were analyzed in onethird of an octave to obtain the propagation attenuation of the vibration. The results show that the three vibration reduction measures reduced vibration. The vibration reduction of the doublelayer nonlinear vibration reduction fastener was 7.3 dB; the vibration reduction was 16.2 dB for the vibration damping pad floating plate and 19.7 dB for the steel spring floating plate.

Addressing shortcomings in the current customer service system, including low awareness of passenger service needs, limited service channels, high costs, and inefficient operation control, this study starts by examining highquality and efficient travel demand in the modern era and analyzing diverse passenger group travel needs. We advocate for new service goals centered on timeliness, convenience, accuracy, and proactivity. The proposed smart passenger service architecture for urban rail transit embraces the multitude of online and offline demands, overcoming existing system limitations in data integration, equipment platform unification, service quality, and efficiency. Emphasizing adherence to passenger service schedules, it also prioritizes efficient lastmeter service delivery. By showcasing representative Beijing subway lines, we present a replicable technological system and application model that can comprehensively enhance the intelligent service and management processes of China's urban rail transit system.

The subway engineering department regularly operates track inspection vehicles to detect the state of the tracks, which is crucial for residents' safe travel. The operational path of track inspection vehicles mainly relies on expert judgment, which is not only a timeconsuming practice but is also ineffective. To address the shortcomings of the current lack of systematic planning for the operational paths of track inspection vehicles, this study, set against the backdrop of the urban rail transit network, constructs a largescale subway inspection vehicle routing optimization model named Urban Track Inspection Vehicle Routing Problem (UTIVRP), under the conditions of a complex network. Considering the characteristics of subway networks, a cultural genetic algorithm with a special encoding method is designed and validated using practical examples from the Beijing subway. The computational results indicate that under the conditions of meeting the established inspection requirements, the optimization solution can not only reduce the idle mileage of vehicles by 48.88%, but also decrease the maximum deviation rate of the network's inspection interval by 93.33%.

This study employs prevalent international statistical standards to categorize urban rail transit into three types: metro, light rail, and tram. It presents a comprehensive statistical analysis of the current state of urban rail transit systems across the globe. As of the close of 2023, urban rail transit systems have been established in 563 cities spanning 79 countries and regions, with a cumulative track length exceeding 43,400.40 km. Subways, light rails, and streetcars account for 50.07%, 10.69%, and 39.24% of the total length, respectively. Notably, as of December 31, 2023, 66 cities in China (including Hong Kong, Macao, and Taiwan) have commenced rail transit operations, boasting a combined operational track length of 11,900.29 km, with Chinese mainland alone contributing 11,232.65 km to this total. In 2022, the metro systems in 183 cities across 59 countries globally handled a total of 58,652 million trips of passengers, representing an average ridership intensity of 0.81 trips per day per kilometer. Specifically, China's metro systems (including those of Hong Kong, Macao, and Taiwan) registered an annual passenger traffic volume of 21.251 billion trips. The study underscores the steadfast advancement of China's urban rail transit systems, which consistently lead the world in both network scale and passenger traffic. Through an indepth analysis of data subsequent to the release of Document 52 by the State Council, this study anticipates a resurgence of lowcapacity urban rail transit systems, particularly streetcars, in Chinese mainland, especially in the central and western regions, in a bid to drive environmentally sustainable urban development. Further, by drawing on data from major countries and cities worldwide, both preand postpandemic, the study predicts a return of passenger traffic in Chinese mainland to prepandemic levels by 2024-2025.

Field experiments and simulation analyses were conducted on a Kaifengsuspended monorail demonstration line to evaluate the service performance of rubbertire suspended vehicles and steel guideway bridges and provide appropriate criteria and operating and design parameters for this type of vehiclebridge system. A rubbertire suspended trainsteel and guideway bridge coupling analysis program was developed. The vehiclebridge coupling model was built according to the measured parameters, including the stiffness and damping of the pneumatic spring and travel wheels. The calculated and measured dynamic responses of the vehicle and bridge were compared. The dynamic performance of the vehiclebridge structure was evaluated based on the calculations and related specifications. The results show that 1) it is feasible to use the vehiclebridge coupling simulation method to investigate the structural vibration performance of a suspended monorail system; the simulation results were consistent with field measurement results; 2) the ratio of the vertical deflection to the span of the steel guideway girder was less than the limit given in the specifications and the vertical stiffness of the structure was reasonable; 3) the maximum vertical and lateral rotation angles between two adjacent beams at the beamends were 4.5‰ and 1.5‰, respectively; 4) the maximum dynamic factors of longitudinal and lateral stress of the steel guideway beam were 1.17 and 1.14, respectively, at a vehicle speed of 80 km/h; 5) the unloading factor of the wheel and lateral acceleration of the guideway bridge were larger than those of conventional railway systems; the limits of these two indices could be set higher than in the current railway specifications as the suspended trains were unlikely to derail.

Passenger flow forecasting for the initial operation stage of a new rail transit line is fundamental for operational safety assessment and organizational preparation. This study analyzes the characteristics of forecasting work in terms of the forecasting period, research objects, basic modeling data, and forecasting models. The technical difficulties in carrying out such forecasting work are also summarized. Considering the characteristics and difficulties of forecasting, this study introduces a new forecasting framework, and the key procedures in the framework are then explained, including data collection, traffic surveys, analysis of the operational characteristics of urban transport, travel demand forecasting from macroscopic and intermediate perspectives, forecasting evaluation, and sensitivity analysis. Finally, the study also discusses main research points of forecasting work with respect to network passenger flow indices, the impact of a new line on the existing network, and the necessary concerns of essential stations. It is suggested that the forecasting work should focus on the current state of urban systems. Thus, it is essential to collect and understand the current information on urban traffic and the city itself and to analyze shortterm development trends. Because the macroscopic demand analysis models may have lower accuracy, it is also necessary to construct a thematic model for rail transit systems based on urban transport macroscopic demand analysis by conducting traffic surveys. The results of this study can provide references for technical methods and research content of passenger flow forecasting in the initial operation stage.