In order to analyze the development and current research status of urban rail transit network performance evaluation, in urban rail transit networks this paper conducts a quantitative analysis of the literature from the CNKI database based on CiteSpace software. This paper gradually focuses on three levels of research: urban rail transit, urban rail transit network, and urban rail transit network performance evaluation, and analyzes the information such as the number of publications, authors, literature sources and keywords. By tracing the important literature, the main indicators of rail transit network performance evaluation are summarized, and the advantages and disadvantages of different evaluation methods are commented. The results show that the research on performance evaluation of urban rail transit networks is undergoing several important transformations. Firstly, the analytical model is developed from unweighted network to weighted network model, which pays more attention to the differences between stations and intervals. Secondly, the research object was extended from the analysis of rail transit network to the comprehensive evaluation of coupled transportation networks such as railroad and railbus. Finally, the research focus of network performance has gradually shifted from the resistance ability under disasters or external shocks to the resilience evaluation including the postdisaster recovery ability.

The positive externalities of urban rail transit necessitate a comprehensive economic costbenefit analysis when evaluating project economic feasibility. In response to the latest requirements for preparing the outline and explanation of the project feasibility report, this study conducted a multidimensional study on the economic costbenefit of urban rail transit. Firstly, identify economic costs and benefits from three dimensions: government, enterprises, and the public, establish a threelevel quantitative+qualitative indicator system, expand quantitative indicators from 5 to 13, and add 14 qualitative indicators; Secondly, conduct research on key indicator analysis methods, propose quantitative methods for driving GDP, fiscal revenue, and increasing employment, break through the current difficulties in evaluating the macroeconomic contribution of urban rail transit, and improve the calculation methods for time saving benefits, fatigue reduction benefits, and traffic accident reduction benefits; Finally, it is clarified that there are 9 indicators that can be included and 4 indicators that cannot be included in the economic costbenefit analysis flow table, and a comprehensive evaluation of the project's economic costbenefit is conducted through case studies to provide support for earlystage decisionmaking and promote sustainable development of the industry.

To address the difficulty in selecting urban rail transit projects in large cities, a model for evaluating the selection of urban rail transit construction projects was constructed based on the analytic network process (ANP). Based on the policy requirements and the demands of relevant stakeholders, five evaluation criteria are proposed: urban coordination, social impact, construction implementation costeffectiveness, postconstruction traffic effects, and network service improvement. These criteria are further refined into nine evaluation indicators. An evaluation model operation platform was constructe, and the evaluation model was verified using a city in Southwest China as a case study. The technical route of the evaluation model conforms to the decisionmaking logic for selecting urban rail transit construction planning projects. The input data of the evaluation model are all data that can be obtained during the construction planning phase. The output results of the evaluation model can intuitively reflect the priority ranking of the candidate projects.

During subway train operation in tunnels, piston wind is generated, which significantly affects the tunnel flow field. Understanding piston wind characteristics is crucial for its effective utilization. It is of great significance to study the characteristics of piston wind for rational utilization of piston wind. Based on Bernoulli equation of unsteady flow, a lumped parameter theoretical model of piston wind in subway tunnel is established, and the characteristics of unsteady piston wind are analyzed. In order to verify the accuracy of the theoretical model, a reduced size model test bench of 1:16 was established, and the piston wind speed was tested experimentally. The comparison between the model value and the measured value shows that the Pearson correlation coefficient is higher than 0.98, and the average error is lower than 13%, which verifies the correlation and accuracy of the theoretical model. By using the lumped parameter theory model, the influence of different factors on the piston wind in subway tunnel is explored, and the grey correlation degree is analyzed. The results show that the congestion ratio is the biggest factor affecting the ventilation effect of the tunnel piston, followed by the train length and train speed, and the tunnel length is the least. Based on this, a fitting formula for the ventilation effect of the piston in common subway tunnels in China is proposed.

This study investigates the challenges of "recruiting and retaining talent" in China's urban rail transit industry. Based on a sample of Beijing Jiaotong University graduates employed by metro companies between 2018 and 2024, a comprehensive survey was conducted across five dimensions: graduate demographics, employment locations, jobseeking processes, factors valued by graduates, and jobposition fit. A multidimensional analytical framework was developed using 539 valid questionnaire responses and a Logit model to identify key factors affecting recruitment outcomes. The findings reveal that recruitment effectiveness is influenced by multiple factors, including geographical preference matching, alignment between organizational development and career aspirations, knowledgeskill compatibility with positions, and job identification. Based on these findings, seven optimization strategies are proposed: optimizing job position and educational qualification matching, addressing the underlying impact of jobseeking processes on satisfaction, strengthening geographical alignment between positions and job seekers' preferences, providing career guidance for diverse career expectations, ensuring precise matching between job skill requirements and graduates' competencies, developing a diverse talent ecosystem, and enhancing career planning education. These strategies provide empirical evidence for talent policy formulation and recruitment efficiency improvement in the urban rail transit industry.

The success of rail transit hubs with three or more intersecting lines heavily depends on their planning and design quality, as these hubs face challenges of high passenger volumes and complex traffic organization. This paper discusses the planning and design practices of the Gangxia North Transit Hub in Shenzhen as a case study. It elaborates on the planning methods and technical system for creating integrated urban transit hubs in the core areas of major cities, touching on aspects such as the functional positioning analysis of the hub, passenger flow demand forecasting, overall planning layout, comprehensive development of the hub, underground space planning, and improvements to the surrounding road traffic. The planning and construction of multiline rail transit interchange hubs play a significant role in promoting the integration of stations and cities, invigorating urban development vitality in the area, guiding the transformation of urban transportation development models, and fostering the sustainable development of urban rail transit.

This study analyzes commuting patterns in urban rail transit and investigates the characteristics and regularities of different commuter types. The analysis is based on Changsha Metro AFC data, covering two consecutive weeks of working days from March 21 to April 3, 2023. A Gaussian Mixture Model (GMM) is constructed using three variables: morning boarding time, evening boarding time, and the average commuting duration. This model classifies passengers into three categories: the classic commuting pattern, the offpeak commuting pattern, and the longdistance commuting pattern. The results show that classic commuters primarily commute during regular peak hours (7:30–8:30 and 17:30–18:30), while longdistance commuters tend to start slightly earlier, and offpeak commuters avoid peak periods, with their morning boarding times spanning from 7:00 to 12:00 and evening boarding times concentrated between 20:00 and 22:00. In terms of commuting duration, classic and offpeak commuters typically travel for 15 to 30 minutes, whereas longdistance commuters predominantly travel for over 30 minutes. Additionally, the residential and workplace station distributions highlight that longdistance commuters are more likely to reside in peripheral urban areas, and the workplace stations of offpeak commuters are more concentrated than those of the other two groups, predominantly located in areas bustling with dining and entertainment activities.

A specific adjustment plan for the control and protection areas in karst region was proposed in response to the problem that the degree of expansion of the control and protection areas for urban rail transit in karst geology was unclear. Starting from the mechanism of karst adverse geology affecting the safety of existing structures, through the study of guiding industry standards and the mechanism of karst ground collapse, three important indicators of the scope of control and protection areas for urban rail transit in karst region were determined: the scope of influence of external operations, the scope of influence of karst ground collapse and the scope of susceptibility to influence of existing urban rail transit structures. Based on geometric analysis, the maximum scope where the existing urban rail structure suffered a safety risk caused by karst ground collapsekarst, which is induced by external operations, is determined. This maximum scope is adopted as the scope of the control and protection areas in the karst region. Finally, the control and protected areas scope calculation models of metro station and interval tunnels in two typical karst geological conditions are proposed. Calculations were carried out on Shenzhen Rail Transit Line 16 as an example, and the results can provide a reference for the operation and management of urban rail transit projects in Shenzhen and other karst regions.

This study investigates the unsteady aerodynamic characteristics of urban trains passing through most criticallength tunnels through numerical simulations. The threedimensional unsteady Reynoldsaveraged NavierStokes (RANS) equations coupled with the Renormalization Group (RNG) kɛ turbulence model were employed to analyze the aerodynamic behavior of an urban train operating at 160 km/h. The results reveal that train operation significantly modifies the flow field structure and pressure distribution within the tunnel, characterized by distinct regional patterns. These modifications are primarily attributed to two factors: the propagation and reflection of traininduced pressure waves, and the compression effect of the train body on the tunnel air. Significant differences are observed between pressure variations on the train surface and tunnel wall monitoring points. While the train surface pressure is predominantly influenced by the arrival timing of compression and expansion waves, the tunnel wall pressure exhibits more complex evolution patterns due to the combined effects of train disturbances, pressure waves, and lowpressure regions. The aerodynamic drag is mainly pressureinduced and significantly affected by both blockage effects and pressure waves. Furthermore, distinct unsteady aerodynamic responses are observed among different car bodies: the first three cars are primarily affected by entrance and exit disturbances, while the rear five cars experience additional pressure wave effects, resulting in substantial fluctuations in lateral force, rolling moment, and yawing moment.

Current lighting control methods for urban rail transit platforms suffer from simplistic control mechanisms and low accuracy, leading to significant energy waste and failure to provide passengers with a comfortable lighting environment. Based on the characteristics of passenger flow, zonal functional features, and psychological needs of passengers, this paper proposes an energyefficient lighting control method for urban rail transit platforms using passenger density as the primary parameter. The method first establishes a functional relationship between passenger density in different zones and time periods and the required illuminance levels by analyzing the spatial characteristics of platforms and temporal variations in passenger psychology. Subsequently, a linear programming optimization model is developed with the goal of minimizing platform lighting energy consumption, subject to illuminance requirements, using luminaire dimming coefficients as control variables. The model is solved using the simplex method, and case studies are conducted. The results show that in lowpassengerflow stations, compared to conventional control methods, the proposed method reduces platform lighting energy consumption by 27.68%, 38.16%, and 38.87% during morning peak, evening peak, and offpeak periods, respectively, while maintaining illuminance levels within the appropriate range. This method effectively reduces energy consumption and enhances the lighting comfort of urban rail transit platforms.

To address issues such as tongue breakage, platform and bottom plate detachment, and conversion failure in welded slide plates for urban rail transit turnouts, as well as the challenges of complex casting processes, slag inclusion, shrinkage, and high scrap rates in integral cast slide plates, this study proposes optimization and improvement measures. These include enhancements in structural design, casting processes, surface friction reduction, and nondestructive testing. The traditional oil maintenance method, which leads to heavy maintenance workloads, track contamination, erosion of fastener backing plates, and reduced durability, is replaced with a new design approach. The reliability and superior performance of the newly developed integral cast slide plate were validated through theoretical analysis and laboratory tests, followed by online trial installation. Results indicate that the new integral cast slide plate significantly reduces maintenance workloads in turnout areas, enhances maintenance convenience, and offers valuable insights for future optimization and defect management of turnout slide plates. Key aspects of the design, production, and testing of slide plates were optimized and improved, focusing on structural design, casting processes, surface friction reduction, and non-destructive testing. The reliability and superior performance of the newly developed integral cast slide plate were validated through theoretical analysis and laboratory testing, followed by online trial installation. Results from the trials demonstrate that the proposed integral cast slide plate significantly reduces maintenance workloads in turnout areas, enhances maintenance efficiency, and offers valuable insights for future optimization and defect management of turnout slide plates.

To address the issue of settlement in existing subway tunnels due to the construction of new adjacent tunnels, an automated machine learning approach and a strategy for weighting multisource data were employed. A predictive model was developed, taking into account tunnel characteristics, stratum properties, and relative positional relationships as input parameters, with the settlement values of the existing tunnels as the output. The model was tested using tens of thousands of simulation data points and realworld data. The findings suggest that while the automated machine learning algorithm can produce a highly accurate predictive model based on simulation data, it may not perform as well with multisource data sets. By assigning weights to multisource data, the model's ability to generalize can be improved, leading to an optimized model that specializes in realworld data, based on simulation data. When the quantity of weighted realworld data is comparable to the simulation data, the model's error rate is reduced. Additionally, according to the feature importance of the bestperforming model, the stratum loss rate emerges as a critical input parameter for prediction, with the significance of geological conditions, spatial relationships, and construction attributes being nearly equivalent.

Addressing the challenge of shallowburied box tunnel machine passing under significant risk sources, this study takes the closerange underpass of the expressway by the underground passage box tunnel machine at Sanyuanqiao Station of Beijing Subway Line 12 as the background. Numerical simulation was used to precisely model the roadbed pavement structure layer of the expressway and simulate the entire construction process of the underpass. The ground surface deformation patterns caused by the box tunnel machine under the expressway were analyzed, and a parameter sensitivity analysis was conducted on construction parameters such as the support pressure at the pipe head, ground loss, and grouting pressure during the pipe jacking construction. Finally, video monitoring was used to monitor and verify the settlement of the expressway. The results show that the ground surface deformation caused by shallowburied box tunnel machine can be summarized into three stages: slight surface uplift, rapid surface settlement, and final settlement stabilization. Changes in ground loss and grouting pressure are the most sensitive to settlement variation. The established numerical model can reflect the basic patterns of surface deformation caused by pipe jacking construction, as indicated by onsite video monitoring data. The maximum settlement of the highway surface meets the control standard of ≤15 mm.

To investigate the diffusion mechanism of backfill grouting slurry in metro tunnels under different working conditions during the operation period, a mathematical model of the diffusion process was derived based on the physical processes involved in grouting. A threedimensional numerical simulation program, developed using the finite element method (FEM) and the volume of fluid (VOF) method, was applied. Using an actual project during the operation period as a case study, the diffusion behavior of backfill grouting in metro tunnels under different soil conditions was simulated, and the rationality of the numerical simulation results was validated through laboratory model tests. The results indicate that in hard soils, the slurry predominantly fractures in a direction perpendicular to the lining structure, making it difficult to form a large closed reinforcement area behind the lining. In contrast, in soft soils, as the grouting pressure increases, the slurry gradually spreads along the interface between the tunnel and the soil. Upon completion of grouting, the slurry forms a uniformly distributed closed reinforcement along the tunnel wall. The consistency between the model test and numerical simulation trends confirms the reliability of the grouting diffusion mechanism behind the tunnel wall.

To ensure the structural safety of existing shield tunnels during nearzero distance deep excavation and address the challenges of retaining structure construction and ground reinforcement under low clearance conditions, this paper presents a case study of a pump station excavation project in the Yangtze River floodplain area. The protection measures include Metro Jet System (MJS) piles with Hsteel insertion using highfrequency hydraulic resonancefree hammer, and synchronous prereinforcement inside the shield tunnel using longitudinal braces and filament wound profiles. Through comparative analysis of threedimensional numerical simulation and field monitoring data before and after deep excavation, the soil squeezing effect and timespace effect on the tunnel structure were effectively controlled. These findings can provide valuable reference for the design and construction of similar excavation projects.

In response to the problem of setting rail cant under the dynamic changes of subway wheel profile, this paper measured the wear profile data of LM wheels at four operating mileage, established a subway vehicle system dynamics model, and analyzed the influence of rail cant on the vehicle's straightline stability and curve passing performance considering during the dynamic changes of wheel profile. The entropy weight method is used to comprehensively evaluate the dynamic performance of the vehicle, and the optimal rail cant setting scheme is obtained for straight lines and curves with different radii considering under the dynamic changes of the wheel profile. Research has shown that when a vehicle is running in a straight line, the coupling of rail cant and wheel wear profile has a more significant impact on lateral stability than vertical stability. The dynamic changes in the wheel profile exacerbate the impact of rail cant on vehicle stability. During the curve operation, when rail cant is constant, the vehicle's curve negotiation performance first deteriorates, then improves, and then deteriorates as the wheel wear profile dynamically changes; When the wheel wear profile is constant, as the curve radius increases, the influence of the rail cant on the vehicle's curve negotiation performance gradually increases. Taking into account the dynamic changes in the wheel profile, the optimal matching of the outer/inner rail cant for straight, R300 m, R400 m, R500 m, and R600 m curve is (1/30, 1/40),(1/20, 1/20), (1/20, 1/40), (1/40, 1/40), and (1/40, 1/40), respectively.

This paper addresses the issues of inefficient recovery of regenerative braking energy, limited substation power supply capacity, and insufficient response to emergency traction in urban rail transit when using single energy storage systems. The research focuses on the application scheme and technical advantages of a supercapacitorlithium titanate battery hybrid energy storage system. First, by comparing supercapacitors, lithium titanate batteries, and flywheels in terms of key parameters such as power density, energy density, and cost, energy storage media are classified into two categories: powertype and energytype. Then, simulation results demonstrate that the hybrid energy storage system composed of supercapacitors and lithium titanate batteries outperforms single energy storage solutions in terms of recovering regenerative braking energy, enhancing substation power supply capacity, and providing emergency traction capabilities for trains. Based on this analysis, the study highlights the application potential of the supercapacitorlithium titanate battery hybrid energy storage system in urban rail transit, particularly its notable advantages in regenerative energy utilization technologies.

Unreasonable grounding system can cause problems such as increased train axle potential and circular current, as well as bearing erosion, deteriorating the electromagnetic environment of onboard electronic equipment, and thus pose a threat to the safety of train operation. Therefore, it is necessary to design the train grounding system appropriately. First, uniform chain circuit model is used to model the traction power supply system and dual current train grounding system. Secondly, through traction and power supply calculations, the train current can be obtained. Taking train current as the excitation source, the distribution of train axle voltage and circular current can be obtained. Take the currents of grounding resistors as a measure of the vehicle circular current distribution. Finally, PSO algorithm is used to optimize the train grounding system. After the optimization, the maximum circular current decreases by about 20%, and the maximum vehicle axle voltage declines slightly. The optimization of the train grounding system in this article presents a guide for the design of the grounding system for dualsystem trains, as well as provides a reference for other trains.

Bidirectional substations have advantages in regenerative braking energy utilization of urban rail transit because of their controllable output voltage, capability of unity power factor operation, and bidirectional energy flow. Due to voltage sensor errors and line parameter inconsistencies, the two converters in the substation generate significant unbalanced currents. While increasing the converter output current feedback coefficient can reduce the current difference between converters, it consequently intensifies the output voltage fluctuations of the substation. On the basis of droop control strategy based on converter output current feedback, a droop control strategy based on substation output current compensating voltage command value is proposed by adding a voltage compensation term proportional to substation output current. The results show that this strategy can improve the current balance between converters and reduce the fluctuation degree of substation output voltage. Finally, the simulation model is built in MATLAB/Simulink, and the example analysis is carried out to verify the effectiveness of the proposed strategy.

The fully automatic operation (FAO) system has become the mainstream of urban rail transit in China. Considering factors such as safety and timeliness of emergency response, at present, FAO lines in China still operate in a staffed manner, failing to give full play to the fully automatic advantage. To address the concerns of operation units and improve the efficiency of emergency response for equipment failures, this paper proposes an emergency plan framework related to FAO line directed by key equipment based on extensive survey on the current emergency plans of fully automatic operation lines in multiple cities. Aiming at the problems of insufficient completeness and poor operability of current emergency plans, a design method of emergency plans for fault handling that integrates failure mode analysis (EMEA) and entropy weight method (EWM) is proposed. Considering five factors such as the severity, occurrence probability, scope of influence, difficulty of isolation, and difficulty of operation restoration, objectively calculate the comprehensive fault impact index, combined with system design information and operation log data. Based on this impact index, operators can determine the fault handling strategy and design the emergency plans. Finally, taking the axle counter equipment as an example, the equipment fault mode is classified and an emergency plan is designed targeted with 85 months of fault log data of a certain line. The results show that the completeness and operability of the failure handling emergency plan have been effectively improved.

To improve the visualization of switch machine status monitoring and the intelligence of fault diagnosis by urban rail transit operators, a 3D visualization monitoring and fault diagnosis method of switch machine based on digital twin is proposed, which provides a powerful technical support for the realtime monitoring of switch machine status, highquality transmission of operation data, and the precise alarm of equipment faults. Compared with the existing intelligent operation and maintenance system of Switch Machines, this study uses digital twin technology to establish a highfidelity model, maps the fieldworking Switch Machines in the information space through realtime interaction of data, and realizes threedimensional visual monitoring of Switch Machines indoors through WebGL and model lightening technology; in view of the small number of samples of fault data for switch machines in the field, it establishes a combined model of CNNTransformer to achieve fault diagnosis. To achieve the fault diagnosis of switch machines, the fault diagnosis accuracy rate is 98.67% under the condition of imbalance between normal data and fault data; In order to verify the feasibility of the proposed framework and the improved algorithmic approach, a 3D visualization monitoring and fault diagnosis platform for switch machines based on digital twins is designed.