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.

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.

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.

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.

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.

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.

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 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.

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.

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.