Intercity railways in the GuangdongHong KongMacao Greater Bay Area (GBA) face operational challenges when used for public transit. These challenges include unclear functional specialization, misalignment with urban development plans, and insufficient network operation, leading to low service efficiency. This study proposes a reorganization strategy informed by successful regional rail transit practices globally. The strategy focuses on three key areas: (1) Reorganizing intercity railways, urban express lines, and other rail lines based on distinct functional levels for optimized service allocation. (2) Optimizing the network layout based on urban travel demand characteristics. This includes optimizing external corridors, strengthening fast and direct connections within the core area, and further strengthening urban rail interconnection through station wiring and connecting lines. (3) Optimizing intercity station and transfer services to improve passenger experience. Implementing these strategies is expected to provide valuable insights for improving operational service levels and promoting the sustainable development of intercity railways in the GBA.

In response to the absence of experimental verification of smoke control and ventilation models for tunnel fires without fire doors in crosspassageways of urban rail transit projects, this study conducted a comprehensive ventilation and smoke control experiment in a typical tunnel of the Zhengzhou Metro. The experiment focused on varying locations of train fires within the tunnel. By assessing smoke control wind speeds in both the fire tunnel and crosspassageway under different conditions, our objective was to validate the impact of not installing fire doors in crosspassageways on tunnel fire ventilation and smoke control, and to evaluate the effectiveness of different ventilation and smoke control models. The results indicated that in tunnels with fully enclosed platform doors and one crosspassageway in the test sections, the absence of fire doors (i.e., with open fire doors) resulted in all tested ventilation and smoke control models achieving wind speeds exceeding 2 m/s blowing towards the side where the fire occurred at the door openings. Simultaneously, exhaust wind speeds inside the fire tunnels exceeded 2 m/s, meeting the regulatory requirements for smoke control. These findings suggest the feasibility of omitting fire doors in similar projects. Different ventilation and smoke control models demonstrated varying wind speeds at door openings. Models utilizing two tunnel fans to supply air to the fire tunnel and pressurize nonfire tunnels, coupled with four exhaust fans to extract smoke from the fire tunnel, achieved higher wind speeds at crosspassageway entrances.

To address the challenge of effectively managing APT in urban rail transit scenarios, this paper proposes a method that combines attack source graphs with deep traffic learning. This integrated approach merges attack reconstruction with traffic monitoring to facilitate identifying and detecting APT attacks. Experimental results demonstrate that this model can effectively trace the sources of APT attacks. Compared to traditional APT attack detection models based on sandboxes or abnormal characteristics, this combined model significantly improves detection accuracy, precision, recall rate, and other performance indicators.

To investigate the sources and distribution patterns of PM2.5, PM10, and total suspended particulates (TSP) in subway stations, this study conducted particulate matter concentration tests at 11 stations along two subway lines in a city. The test areas included outdoor locations, station public areas, equipment management rooms, and corridors inside the platform end doors. The concentrations of PM2.5, PM10, and TSP in each area were measured, and elemental analysis of the outdoor and platform particulates was performed. Subsequently, the distribution patterns of PM2.5, PM10, and TSP in various areas at different outdoor concentrations were analyzed. Based on the test results, suggestions for subway particulate matter prevention and control measures were proposed. The research revealed a significant increase in iron content in particulate matter within stations compared to outdoor areas. Particulate matter containing iron in subway stations often exhibits irregular sheetlike shapes, differing from those found outdoors, indicating that railwheel friction is the source of these particulates. When outdoor particulate matter concentration levels were low, the distribution patterns of particles of various sizes were similar, generally exhibiting higher concentrations in the tunnels than in the stations and outdoors. However, when outdoor particulate matter concentration levels were high, PM2.5 and PM10 concentrations were higher in tunnels than in outdoor areas and stations. Regardless of outdoor particulate matter concentration, TSP concentrations in public areas and carriages were consistently higher than outdoors. These findings provide valuable insights for developing effective particulate matter prevention and control measures in subway systems.

To identify key stations in urban rail transit networks and study their evolution over multiple years, we developed a key station recognition method based on truncated singular value decomposition (TSVD). We selected origindestination (OD) data from the morning peak hours between 2011 and 2019 in Beijing as the dataset. The analysis involved evaluating the evolution of network passenger flow and identifying key stations in subway networks using key eigenvectors. These results were then compared with those obtained from complex network methods. The analysis demonstrates that TSVD can effectively identify key network stations by considering the OD distribution. The outcomes from TSVD better represent the spatial distribution of network passenger flow than traditional methods. The results revealed that the spatial layout of key stations in Beijing's urban rail transit has evolved towards multiple centers, such as Northwest Xi’erqi and Southwest Fengtai Science Park. These stations are gradually forming network passenger flow centers and establishing connections. Additionally, stations like Southeast Tu Qiao and Northeast Fengbo are showing preliminary trends toward becoming network passenger flow centers.

To address the shortage of realtime data and the accuracy limitations of existing automatic line control systems, we propose an intelligent upgrade scheme for train control systems. First, considering the distinct characteristics of electric and air braking in train operations, we developed accurate braking models for both systems, incorporating the switch between electric and air braking. Next, we optimized the ATO controller and applied a sliding mode adaptive robust control strategy. This strategy adjusts the controller in real time, enhancing its robustness and adaptability to varying vehicle parameters and external environmental interferences. Using Beijing Metro Line 5 as a case study, we simulated the precise train braking model and the sliding mode adaptive robust controller to calculate the stopping accuracy and speed error of the train. The results demonstrate that, compared to proportionalintegralderivative (PID) control and sliding mode control, the proposed control algorithm significantly reduces parking accuracy and speed errors. Specifically, the average parking accuracy achieved is less than 8 cm.

This study focuses on a straightline section of a subway line to analyze the factors influencing the vibration source strength in subway tunnels. Vehicleinduced vibration signals and velocity signals were collected synchronously, and the timedomain and frequencydomain characteristics of allday test samples were statistically analyzed. The results showed that during peak hours in the morning and evening, the vibration response inside the tunnel may not be completely maximized, and the degree of dispersion of the vibration source intensity is directly related to the vehicle state. The study found an average difference of 6.7 dB in the VLZ of the tunnel wall measurement points caused by V₁ and V2 vehicles. Using more than 40 sets of test samples to calculate the vibration source intensity yielded results closer to the daily sample mean. The main frequency of tunnel vibration caused by the wheelrail system shifts with changes in vehicle speed. A strong linear positive correlation was observed between vehicle speed and the vibration acceleration levels of the track bed and tunnel wall. Specifically, for every 10 km/h increase in vehicle speed, the vibration increases by about 1.7 dB and 2.6 dB, respectively. When the speed difference is within 10 km/h, the vibration source intensity changes within 1 dB; when the speed difference is between 10~20 km/h, the increase is about 1.5~2.2 dB. The coefficient of speedcorrected CV was calculated to be 18.5, aligning closely with the coefficient used for train speed correction in the vibration prediction formula. Tunnel wall vibration was more discrete in the lowfrequency band below 40 Hz, but this band contributed minimally to the source strength of vibration, accounting for 15.29%. The dominant frequency band was 5063 Hz, contributing 59.55% to the source strength of vibration. These research findings can provide a reference for further refining the vibration prediction formula and offer a theoretical basis for improving the accuracy of metro tunnel source strength test results.

The concept of speed efficiency was proposed to measure the travel speed efficiency of urban rail transit lines. This study analyzed the operating data of 170 urban rail transit lines in China, including fully closedoperated subway, light rail, and monorail systems, considering only the train operating mode at station stops. The analysis covered various factors such as average station spacing, line design speed, and travel speed. The results showed that most lines (approximately 64%) have a design speed of 80 km/h, with average station spacing ranging from 1.0 to 2.5 km. Among these lines, about 90% have a travel speed between 30 and 40 km/h, with speed efficiency distributed between 37.5% and 50.0%. Additionally, the study quantitatively analyzed the relationships between travel speed, average station spacing, and design speed, finding both positive and negative correlations. Finally, based on fitted travel speed and speed efficiency formulas and actual data, the corresponding distribution relationships of average station spacing, design speed, travel speed, and speed efficiency were calculated. These findings provide a reference for determining a reasonable travel speed range and speed efficiency for urban rail transit lines.

An integrated spatial finite element model of railbridgepier was developed and validated to investigate the effect of temperature on the interaction between bridges and rails, particularly focusing on smallradius curved bridges used by trams. This study compared and analyzed the bridgerail interaction laws between straight bridges and smallradius curved bridges. It specifically examined the additional expansion force of the rail, lateral forces at the top of bridge piers, and longitudinal forces under overall and local heating conditions. Under overall heating conditions, the research found that smallradius curved bridges experience greater lateral displacement of the steel rail and higher lateral forces at the top of bridge piers compared to straight bridges. Moreover, as the bridge temperature increased, the additional expansion force of the rail also increased. Calculations using overall heating conditions resulted in larger expansion forces and longitudinal forces on the top of piers compared to local heating conditions. Based on these findings, three different fastener arrangement schemes were proposed and evaluated. It was observed that fasteners with lower resistance could effectively reduce the additional expansion force of the rail. However, insufficient longitudinal resistance might increase the risk of rail joint fractures. In conclusion, the study provides valuable insights for designing continuously welded rails on smallradius curved bridges for tram systems, offering guidance on optimizing fastener arrangements to mitigate rail expansion effects while ensuring structural integrity.

To address the urgent need for vibration and noise reduction in the development of upper covers, this paper summarizes existing control measures for tracking vibration and noise in depots, emphasizing the necessity of implementing seamless rails in depot lines. We also examine the requirements for sleepers. Our calculations indicate that depots can meet the strength and stability requirements for seamless lines by using arm span resistance pillows in conjunction with other strengthening measures. Additionally, this paper introduces a seamless turnout technology for No.7 movable turnouts and verifies their seamless integration based on actual usage conditions in Beijing. The findings suggest that both the turnouts and the turnout groups are suitable for seamless application. A comparative test conducted at a speed of 15 km/h reveals that the movable turnout reduces vibration and noise by 35 dB compared to fixed turnouts.