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.

With the rapid pace of urban development, the speed of urban rail transit systems in various cities is gradually increasing. The transitoriented development (TOD) model, which focuses on the comprehensive development centered around public rail facilities, has been widely adopted. This has led to a rise in the number of transfer stations and integrated transport hubs. The TOD approach in domestic rail transit is becoming more diverse, and the integration of station cities helps rail transit TOD reach new levels. Largescale rail transit TOD projects generally require planning in the early stages of the project based on advanced planning and coordinated design methods, which are more conducive to the implementation of the main body to create a comprehensive transportation hub project with core characteristics in the area. This study focuses on the mismatch between the core development area of Dongguan and the timing of rail transit construction there. It summarizes the practical path from early planning to implementation based on line networks and detailed planning research and innovatively proposes the construction of public rail facility coconstruction engineering. Advanced planning, coordinated design, and integrated construction models have introduced new design concepts. The research results indicate that the construction of public rail facilities according to the underground space model has solved the problem of urban, comprehensive hub locations being unable to be developed synchronously because of their inability to initiate and implement rail transit projects, provides new research directions for subsequent project development, design, and implementation, and provides successful cases for government decisionmaking.

The government of Macau is actively promoting rail transportation planning and construction to enhance the capacity of urban transportation systems, promote sustainable transportation development, achieve green development goals, and provide reliable travel options for both Macau residents and tourists. This study analyzes the current state of rail construction development in Macau and summarizes key experiences in rail transport planning. These include supporting the urban pattern, enhancing traffic capacity, optimizing traffic structure, and aligning with public preferences. Additionally, the study outlines technical strategies for deployment, such as serving main corridors, connecting key hubs, integrating multiple modes, and coordinating spatial relationships, thus providing a reference for other cities in rail transport development.

To address the issue of incompatibility between the China Train Control System (CTCS) system used in mainline and intercity railways and the Communication Based Train Control (CBTC system) used in urban rail transit, which hinders the integration of the four networks and reduces the overall transportation efficiency of the rail transit system, research is conducted on main technologies such as onboard equipment, ground equipment, overlapping area design, and system switching process that support the integration of the four networks in the train control system. First, key technologies for integrated onboard equipment were proposed, including automatic train protection technology, automatic train operation technology, humanmachine interface technology, and train interface technology. Second, key technologies for ground equipment in overlapping management areas that support crossline operation of trains were presented, and the overlapping management area design technology that supports safe and smooth switching of train control systems without stopping was provided. Lastly, the system switching process of trains switching from CTCS to CBTC and from CBTC to CTCS without stopping in the overlapping area was explained. The research results suggest that crossline operation can be achieved by integrating onboard equipment that is compatible with ground equipment, reducing the number of ground equipment, simplifying the system structure, and enhancing system safety, reliability, and maintainability while also offering cost advantages. Adopting integrated onboard equipment with a simple system structure, low equipment cost, and minimal space requirements for installation is the future direction of technological development. The key technologies of the train control system compatible with CTCS and CBTC proposed can be used to guide system design, research and development, and application, which has guiding significance for achieving "four network integration."

To enhance the emergency response capability of subway waterlogging, this study investigated waterbarrier technologies and devices for subways, both domestically and internationally. A systematic review of conventional and innovative subway waterbarrier technologies and devices was conducted, focusing on subway waterlogging risk points such as station entrances/exits, vent shafts, main tracks, and vehicle depots. The advantages and disadvantages of various subway water barrier technologies and devices were analyzed. This study discusses the challenges faced by subway water barrier technologies and devices in terms of cost economy, intelligence, automation, and sustainability. Recommendations are provided for structural optimization, material improvement, multifunctional water barrier devices, intelligent and automated control, green technology, and sustainable development. The results indicate that different waterbarrier devices are suited to various application scenarios. Water barrier devices should be selected based on risk points and flood characteristics. Conventional subway water barrier devices are widely used and are technologically mature. Compared with these technologies, new technologies have advantages in terms of automation, resourcesaving, and improved emergency reliability. This study aims to serve as a reference for the design, installation, and application of subway waterbarrier devices, providing technical support for ensuring the safe operation of subway systems and essentially responding to subway waterlogging.

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.

The conventional subway line design method cannot address the issues of a large amount of demolition, complex construction, high risk, and high cost in the densely built areas under construction. This article innovates a line design method that combines a special scissors crossover with a curved islandtype misaligned platform, which not only meets the design needs of related disciplines such as architecture, structure, signal, track, train operation, and line but also allows subway lines to avoid dense buildings around the station flexibly. The results indicate that this innovative route design method can reduce demolition, increase construction clearance, reduce open excavation scale, reduce construction difficulty and risk, and reduce engineering investments. It provides technical guidance for areas with dense buildings, as well as demolition and construction difficulties around subway stations. The application to practical engineering cases demonstrates that this innovative line design method can yield economic, technical, and social benefits.

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.

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.

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.

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.

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.

The mechanism of the geological deformation caused by shield tunneling construction was combined with a threedimensional numerical simulation method to simulate the displacement of bridge piles during the smallangle side crossing of highspeed railway bridge group piles in subway shield tunnels constructed in sandy areas. Analyses were conducted on the mechanism of the impact of metro shield tunnels on highspeed railway bridges when the shield reaches the front of the piles, reaches the piles, and moves past the piles, as well as when the shield tail is detached and after the shield passes the piles. Three protection plans were then proposed for highspeed railway bridges, which included isolation pile measures, geological reinforcement measures, and isolation piles + geological reinforcement. Threedimensional numerical simulations were used to analyze the entire process of shield tunnel boring through the pile groups of highspeed railway bridges under the conditions of no protection scheme and when adopting the above three protection schemes. The findings revealed that without protective measures or with the sole use of ground reinforcement or isolation piles, the deformation of a highspeed railway bridge exceeds the allowable standards during the lateral passage of a shield tunnel. However, with the implementation of both isolation piles and ground reinforcement, the deformation remains within the prescribed limits. After the scheme comparison, the design scheme of isolation piles and ground reinforcement were ultimately adopted for implementation. During the onsite implementation, the entire process was monitored, and the monitoring results were consistent with the numerical calculations, verifying the rationality of the highspeed railway bridge protection plan.

To provide a theoretical basis and reference for crack control during construction, this study first monitored the construction of side walls by embedding temperature and stress sensors. The measured data were then compared with the Midas civil finite element model, the law for a temperature field, and the stress field during the construction of the side walls. The field monitoring and numerical analysis showed that the hydration heat reaction of the concrete in the early stage was relatively fast, reaching its maximum value only 20 h after pouring. The temperature was high in summer, and the cooling rate was relatively slow at approximately 0.40 °C/h. However, the cooling rate of the middle layer was relatively fast. The time at which the compressive stress reached its maximum value was close to that at which the temperature reached its maximum value. Subsequently, it entered the shrinkage deformation stage. After the critical condition of zero stress occurred, the tensile stress gradually increased with a continuous decrease in temperature, and the tensile stress at each measuring point tended to be stable 50 h after pouring. The finite element model results were close to the field monitoring data. Thus, it could play a role in the prediction of and theoretical basis for fractures. It could also be used as a reference for actual fracture control in engineering.

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.

Subway carriages are ventilated from the outside world through fans, which regulate the temperature, humidity, and wind speed of the internal environment of the carriages, improve air quality, and enhance the thermal comfort of passengers. Due to the limited number of applicable thermal comfort evaluation indices, accurately determining the thermal comfort of subway car occupants in transient environments is challenging. This paper first focuses on occupants of a Btype subway compartment as the research subject and proposes the joint application of DRBerkeley thermal comfort evaluation indexes by considering both airflow comfort and heat sensation. The study then employs the Stolwijk physiological model of human thermal regulation to construct a threedimensional model of the amplitudeflow fan and an overall simulation model of the subway compartment. Finally, using CFD software, STARCCM+, the study analyzes the effects of different fan speeds, fan hood disturbance speeds, and fan air supply temperatures on the microenvironment and thermal comfort of the occupants under seven different conditions during the summer. The results show that the DRBerkeley thermal comfort evaluation indexes can reasonably evaluate the thermal comfort of subway compartments under the premise of meeting the airflow comfort in summer; increasing the fan speed, reducing the hood disturbance speed, and reducing the fan air supply temperature can improve the thermal comfort of the occupants; in the seven working conditions, the fan speed of 1,400 rpm, the hood disturbance speed of 3.25 rpm, and the air supply temperature of 20°C have a uniform temperature and speed distribution in the compartments. The temperature and velocity distributions in the cabin were uniform, the occupant microenvironmental heat flow field was optimal, and thermal comfort was 0.766. This method can solve the occupant thermal comfort problem more comprehensively, which is of some reference significance for optimizing the thermal flow field environment in subway compartments and upgrading occupant thermal comfort.

To address the issue of reduced comfort resulting from rapid aerodynamic pressure changes inside the tunnels used for urban rapid transit trains, a study was conducted on the effects of the tunnel diameter and pressurerelief schemes on incar pressure. First, pressure comfort standards were selected based on relevant regulations, and a finite element model was established, which included a train model, a tunnel model, and pressure relief measures at the tunnel entrance. Subsequently, the pressure variations inside and outside of a train were investigated for different tunnel diameters and airtightness indices. Finally, the impact of implementing buffering schemes at the tunnel entrance on the incar pressure was analyzed. The research results indicated that when the tunnel diameter increased from 6.0 m to 6.1 m, the maximum incar pressure variation decreased by approximately 4.2%, with further increases in tunnel diameter having a limited effect on reducing the pressure variation. When the airtightness index was ≤6 s, each additional second resulted in a 15–25% reduction in the maximum incar pressure variation. Additionally, when a fully enclosed sound barrier was installed at the tunnel entrance as a pressurerelief structure, the maximum incar pressure variation could be reduced by approximately 4050%. Measures can be taken to enhance the overall vehicle airtightness, such as improving the seals around the doors for the driver's cab and passenger cars, installing pressure protection valves at freshair inlets and exhaust outlets, and enhancing the seals on the vehicle body and intercarriage passageways.

To address the problems of dynamic failure and different services in the reliability analysis of an LTEM (Long Term Evolution for Machines) trainground radio communication system, this study evaluated the reliability of an LTEM trainground radio communication system based on a dynamic Bayesian network (DBN). First, the reliability block diagram, which was constructed by analyzing the LTEM system structure and function, was transformed into a DBN, and the DBN structure and parameter modeling were conducted. Subsequently, the reliability of the LTEM system was obtained and compared based on the forward inference of the DBN. Finally, based on the backward inference of the DBN, the weaknesses of the LTEM system were recognized as a reference for operation and maintenance. The results indicate that while the LTEM system is highly reliable, the building baseband unit and train access unit are vulnerabilities that require attention.

This study aims to enhance the safety management capabilities of urban rail transit operators by designing and implementing an intelligent safety management platform, which has been validated in practice on Urumqi Metro Line 1. Centered around a dual prevention mechanism, the platform integrates 10 functional modules to achieve risk prediction and early warning, comprehensive safety assessment, safety supervision and inspection, as well as emergency decisionmaking support and resource sharing. The analysis results are presented on the platform interface in a visually graphic format, thereby increasing the efficiency of safety production management. The findings of this research can serve as a reference for the digital transformation of safety management in other urban rail transit enterprises.

Airport rail transit lines serve large airports and differ from ordinary urban rail transit lines in terms of functional role, passenger service, passenger flow characteristics, and service standards. Transport service standards for this type of particular transit line need to be improved. To meet the rapid distribution needs of airport passenger flow and enhance the quality of airport passenger services, designing specific service standards is essential. First, the particularity of the special line is analyzed from the perspectives of service passengers, technical conditions, passengers' travel needs, etc. Second, the existing service standards for rail transit are examined, and the necessity of establishing transport service standards for these special lines is elaborated. Finally, suggestions for designing service standards from the aspects of design principles, standard framework, and key contents of services are provided. This study aims to provide a reference for formulating service standards for special rail transit airport lines.