As subway construction in China continues, the network operation mode of subway emerges, and more transfer nodes are created. Due to planning and other factors, the earlierbuilt subway lines did not reserve future transfer access conditions. Thus, when new lines are built, the existing stations often undergo transfer transformation and upgrading along with the new stations. Among the key tasks involved, the communication transmission system transformation and upgrading is crucial. The communication system is the traffic nerve of urban rail, which consists of public security communication system, civil communication system, and special communication system. It supports the information exchange between the control center and the stations and vehicles, and provides stable communication service for passengers. This paper examines the communication room transformation and communication capacity expansion requirements resulting from the transfer station transformation under the existing line operation conditions, and proposes the enhanced MSTP construction scheme for public security transmission system and the backbone transmission system OTN construction scheme. Xitucheng Station of Beijing Metro Line 10 intersects with the newly built metro Changnan Line, and the transfer station changes in building structure and function have raised new requirements for the communication system equipment deployment and upgrade. This paper applies the design scheme to the transfer project, verifies the rationality of the proposed scheme, and the research results offer an application reference scheme for the communication system upgrade of the existing station transfer transformation.

Fire is one of the most serious accidents occurring at urban rail transit stations. A scientific and reasonable safety evacuation plan is essential to ensure the safety of passengers in the event of a fire. However, it is difficult to dynamically adjust the evacuation routes in the current subway station fire evacuation plan according to the fire situation. This study used computer vision technology to identify personnel distribution information and fire locations based on the monitoring system in the subway station. A spatial topology model was developed, and an improved ant colony algorithm was used to plan an evacuation route that takes the shortest time and has fewer turns to provide a more scientific and reasonable evacuation route for evacuating passengers. The effectiveness of the evacuation plan was verified by applying it to three scenarios.

With rapid urbanization, the refurbishment of urban railway lines is crucial for advancing highquality urban rail development and sustainable urban growth. This refurbishment process presents a host of intricate professional challenges that must be addressed. Meeting current requirements for line reconstruction while addressing safety issues and expanding beyond traditional specialized fields is demanding. Therefore, it is essential to chart a development path for the transformation of existing urban rail transit lines in line with the needs of highquality urban rail development. Drawing on the history of Beijing's line refurbishments, this study examines the challenges and future objectives of urban rail transit line refurbishment and proposes comprehensive concepts for the rejuvenation process. Furthermore, we introduce an innovative approach to investment and financing for line refurbishments, focusing on sustainable urban rail development. We offer recommendations for the transformation of urban rail transit lines in China across six key areas: system development, vitality of components, investment and financing frameworks, technological empowerment, research and development, and relevant standards.

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 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.

Groundsurface deformation characteristics caused by jacked rectangular pipes differ from those caused by jacked circular pipes or shield tunnels. The groundsettlement characteristics during the construction of a shallowburied rectangular jacked pipe and its impact on the existing shield tunnel below the jacked pipe were clarified. Using the onsite monitoring results from jacked rectangular pipe construction, the deformation patterns of the ground surface during jacked rectangular pipe construction and the deformation of the existing shield tunnel below the jacked pipe were analyzed. The traditional Peck formula was applied to circular pipejacking and circular shield tunnels; the improved Peck formula was used to describe the surface deformation caused by rectangular pipejacking. The surface deformation, pipeline deformation, and settlement pattern of the submerged tunnel caused by jacked pipes were analyzed based on field monitoring. The results show that the improved Peck formula can describe surface deformation caused by jacked rectangular pipes more accurately than the traditional Peck formula. The settlement patterns of the surface and pipeline caused by jacked pipes were consistent; however, there were differences in the settlement patterns of the underlying tunnel.

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.

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.