The design standards for the roadbed structure of the metro depot have not been clearly defined in the Metro design specification (2013)," and the current practice of using the main line standard results in high and unreasonable costs. This study relies on the Zhengzhou Metro Tieluxi Depot project to conduct a numerical simulation analysis of dynamic loads under different subgrade structures and to study the variation law of the dynamic load distribution. The dynamic load generated by the ballastless track at the same train speed was smaller than that generated by the ballasted track. An increase in the thickness of the subgrade surface layer has a more substantial impact on reducing the dynamic load generated by the train operation. However, an excessively thick foundation increases roadbed stiffness, which is not conducive to stress dissipation. Hence, when the foundation thickness increases to a certain extent, the effect of reducing the dynamic loads gradually becomes less significant. The numerical simulation results show that the design scheme of the metro depot subgrade can appropriately adjust the parameters on the basis of "0.3 m+0.9 m" and "0.4 m+0.7 m", ensuring that the dynamic and static stress ratio of the subgrade is strictly less than 0.2, attaining the best level of safety and economy.

When a traffic system is abnormal, passengers are prone to blindness, panic, conformity, and other psychological problems. They may thus make incomplete rational decisions. The Multinominal Logit (MNL) model is based on the assumptions of complete information and rationality. It has poor adaptability when used for abnormal situations. Therefore, the incomplete rationality of passengers under abnormal conditions was described using the cumulative prospect theory, and individual differences among passengers were considered to resolve this inability of the classical MNL model. First, the four factors of time, cost, comfort, and convenience were comprehensively considered, and a model was constructed of rail transit nonnormal passenger travel mode selection based on the cumulative prospect theory. It was used to characterize the incomplete rationality of passengers. Afterward, a questionnaire survey was conducted to calibrate the model parameters. Based on the survey results, a differentiated reference point following a Poisson distribution was obtained to describe the reference point dependency phenomenon of the model. The results of a case study indicated that the Poisson distribution test values with the introduction of differentiated reference points met the test criterion of a value that was greater than or equal to 0.05. It explained the essence of passengers' different decisionmaking results and presented a trend of comprehensive prospects fluctuating with the reference points. Finally, this model was compared with the MNL model to verify the rationality of the model. The research results indicated that the model focused on abnormal situations and reflected the incomplete rationality and individual differences of passengers. The overall accuracy was higher than that of the MNL model, and the average absolute error was reduced by 4.9%. The accuracy of the microscopic calculation results was 25.4% better than that of the MNL model. This could provide theoretical support for traffic demand prediction under abnormal rail transit conditions.

This study focuses on a rectangular prefabricated station structure scheme developed and applied for the first time to the Shenzhen Phase V Project. Combined with the evolution process of the prefabricated structure scheme with dry connections, this paper introduces in detail the section design scheme of the rectangular structure scheme, structural partitioning and joint, bracing system of the beamcolumn, and static and dynamic performances. The rectangular prefabricated station structure scheme can be applied to different station width requirements, and an adjustable template is used to effectively improve the universality of the rectangularstructure components. Simultaneously, the rectangular structure can be expanded to accommodate different types of stations, such as threelayer twospan or twolayer threespan. Additionally, the bending bearing capacity of a rectangular assembled station joint was verified by a fullscale joint test, and the adaptability of the theoretical calculation method of the existing joint research to structural size changes was verified. The results of this study are intended to provide a reference and experience for subsequent prefabricated structure designs and engineering applications.

Surface defect detection technology plays an essential role in railway inspections by effectively preventing railway accidents and ensuring operational safety. This study addresses the issues of poor detection accuracy and low sensitivity to small targets in existing railway defect detection technologies. For the mask regionbased convolutional neural network (Mask RCNN) algorithm model, a model improvement scheme was proposed by incorporating an attention mechanism. This scheme introduces a Channelwise Spatial Module (CSM) into the feature extraction network for segmentation defect detection, effectively eliminating interference, obtaining multiscale feature representations, and acquiring more spatial and shallow information, thereby enhancing the edge detection capability for surface defects on railway tracks. In the same experimental environment, compared with the Mask RCNN algorithm, after adding the CSM, the mAP value of the Mask RCNN model increased by 6.5%. Among them, the AP values for the recognition of "depression,” “crack,” and “fatigue wear" defects on railway tracks increased by 6.3%, 6.9%, and 6.1%, respectively. The horizontal segmentation effects of the three defects improved by 11.6%, 12.5%, and 12.9%, respectively, compared with the Faster RCNN model, and the segmentation effects of the three defects enhanced by 8.8%, 10.0%, and 10.3%, respectively. This study demonstrates that the Mask RCNN model with CSM can better recognize three types of defects, enhance the detection accuracy and sensitivity to small targets, provide more secure and robust technical support, and guarantee intelligent track inspection.

As property development above vehicle depots becomes increasingly common, it's crucial to address the construction and operational challenges this poses to the underlying facilities. This necessitates adaptive adjustments and optimizations in various aspects of depot design, including overall layout, fire safety, traffic management, utility systems, and vibration and noise mitigation. By comparing developed and undeveloped vehicle depots, this study proposes an optimization strategy centered on "one core concept and two principles." This approach aims to create favorable conditions for aboveground development while safeguarding the underground facilities' safety and environment, without compromising the depot's scale and functionality. The study outlines optimization strategies across multiple areas, including site selection, layout planning, maintenance procedures, emergency evacuation, ventilation and smoke control, and traffic flow. Specific recommendations include improving stationsection relationships, maximizing land use efficiency, implementing advanced maintenance equipment, and enhancing evacuation and smoke management systems. The ultimate goal is to minimize the negative impacts of aboveground development, fostering a harmonious relationship between the aboveground and underground facilities for mutual benefit.

Concerning the noise pollution caused by the operation of the ground line of urban rail transit, the access line of the Zhongzhou Avenue depot in Zhengzhou Metro Line 5 is taken as an engineering example. The noise is tested in situ before and after the installation of sound barriers, and the noise reduction process is simulated with Virtual Lab software. The simulation results are in good agreement with the tested sound pressure level changing with the sound source frequency, and the accuracy of the acoustic simulation model and calculation method is verified. The insertion loss of sound pressure level is adopted to characterize the noise reduction effectiveness of the sound barrier, and further research are conducted on the noise reduction effectiveness of triangular wedge, QRD (Quadratic Residue Diffuser) sequence, PRD (Prime Root Diffuser) sequence and micro perforated panel PRD I composite sound barrier, and the results reveal that the wedge angle significantly impacts the noise reduction effectiveness of the triangular wedge sound barrier; greater irregularity enhances the diffusion effect for diffracted sound in PRD sound barriers, and PRD sound barriers exhibit better noise reduction effectiveness than QRD sound barriers; the overall noise reduction effectiveness of PRD type I sound barrier is slightly higher than that of PRD type II sound barrier, to reduce appropriately the design frequency of the diffusion body, increase the order, and expand the slot width can advance the noise reduction performance of the PRD type I sound barrier; to add micro perforated plate resonance sound absorption structure in the diffuser end groove of micro perforated panel PRD I composite can further improve the noise reduction of the end structure of diffuser, which would have an ideal application prospect for improving the noise environment of metro access lines.

In the overall structure of a shield tunnel, the joint of the pipe segments is the weakest part of the waterproofing system, and its waterproofing performance directly influences the stability and service life of the entire tunnel. With continuous innovation and changes in structural design and construction methods, the occurrence of water leakage or sealing gasket damage at the joints of pipe segments has become increasingly severe. Therefore, research and optimization of waterproofing performance are crucial. This study begins with the waterproof principle of elastic sealing gaskets and deeply analyzes the factors that affect joint leakage, based on which specific optimization measures were proposed for the waterproof performance of pipe joints. Finally, to verify the actual effectiveness of these optimization measures, empirical research was conducted on a new type of shield tunnel project in Jiangxinzhou, Nanjing. The main conclusions of the study are as follows: the physical properties and durability of EPDM gaskets must strictly comply with regulatory requirements; The adhesive work of the onsite sealing gasket and the tensile deformation of the onsite pipe segment assembly on the sealing gasket is essential factors impacting the leakage of water at the joint; The solid section structure at the corner of a largediameter high water pressure shield tunnel requires to be optimized to avoid issues such as corner accumulation and stress concentration caused by the crosssectional size of the sealing gasket; The monitoring results after the tunnel is completed indicate that the optimized shield tunnel not only has good forming quality but also has a much better waterproof effect than traditional shield tunnels. This study not only provides a theoretical basis and practical guidance for the waterproof design of shield tunnel segment joints but also provides a valuable reference and inspiration for similar projects.

To demonstrate the necessity and rationality of interconnecting Chongqing rail transit lines between core hubs based on the concept of urban rail transit interconnection, this study summarizes the macro positioning of planning fit, improving service quality, guiding urban development, and implementing resourcesharing using the example of Chongqing rail transit lines 26 and 27. It also analyzes the economic benefits, operating losses, and civil investment increases caused by the interconnection mode. With the effect of the time value, the converted net present was used as the measurement index of the necessity and rationality of the interconnection to exhibit rail transit lines 26 and 27 between the core hubs. The results demonstrate that the converted net present value of the interconnection with Chongqing rail transit lines 26 and 27 between the core hubs is greater than zero. The necessity for interconnection is significant, and the scheme is reasonable and should be recommended. Considering the necessity of urban rail transit interconnections, this study proposes an analytical framework that combines qualitative and quantitative analyses, enhances the research system of urban rail transit interconnections, and provides an effective reference for the planning and design of similar projects.

Urban rail transit dispatching and command work involve complex system engineering, and the emergency dispatching and command system, as the top priority of urban rail transit dispatching and command work, directly affects the level of enterprise operation services and train operation safety. The emergency dispatch and command system is a paramount component within this framework. Using the Tianjin Metro emergency dispatch as a case study, this research first outlines the foundational modes of emergency dispatch and command used in domestic urban rail transit. It also integrates current trends in information integration and intelligent operations within urban rail transit. The study then delineates the objectives and functional requirements specific to the Tianjin Metro emergency dispatch and command platform. It proposes an architecture comprising several key layers: infrastructure, data resources, application support, application software, information display, regulatory standards, and security systems. This structured approach ensures comprehensive coverage of operational needs and regulatory compliance. Furthermore, leveraging technologies such as cloud computing and big data, we explored the technical scheme and implementation plan of the Tianjin Metro emergency dispatch command platform for the integration demand and intelligent trend. The research results can provide decision support for the safe and orderly operation and dispatch of subways under networked conditions.

In recent years, with the comprehensive transformation and upgrading of the national economy, Beijing's urban development model has shifted towards a more scientific, sustainable, and highquality approach. The relationship between rail transit and urban development has been reevaluated, leading to the emergence of the "urban followtrack construction" planning concept. This study examines the current issues in Beijing's rail transit system, summarizes the experiences of integrating and developing rail transit station cities, reviews recent policy guidelines related to stationcity integration in Beijing, and offers new insights and perspectives on the station planning concept for rail transit lines. In terms of urban rail transit network planning, the focus is on selecting appropriate corridors and nodes to enhance interaction with urban planning. For route planning, attention is given to resource matching between stations and surrounding land, aiming to balance the planning and construction processes for mutual benefit. By integrating the lessons learned from actual engineering projects, this new planning concept is applied to practical engineering, providing a reference for the integrated development of Beijing's rail transit station cities.