The network operation of urban rail transit has introduced diversity in passenger route choices. It is difficult to accurately determine passengers' network route choices based on existing Automatic Fare Collection (AFC) transaction data and probabilistic inference methods. This difficultyaffects tasks such as rail transit network passenger flow allocation and ticket clearing. This study utilizes network station information to construct an urban rail topology network. The proposed method searches for feasible path sets for OriginDestination (OD) pairs and uses multisource data, including AFC transaction data, mobile signaling data, and train schedule data, to build a nonlinear optimization model to infer passengers' travel route choices. Experiments based on the Nanjing Metro network show that the model is effective and robust. This study can provide guidance for urban rail transit operations and ticket clearing.

Given that passenger flow distribution in urban rail transit station facilities is limited by the capacity and topology of these facilities, making quantification difficult, this study addresses this issue by analyzing the current state of research on passenger flow in station facilities. First, an analysis of the passenger flow state and its transformation within station facilities is conducted. Based on the capacity and transit capacity of the facilities, a passenger flow state transition model is constructed using queuing theory to describe the probability of congestion and dissipation at facility junctions. Taking an urban rail transit interchange station as an example, an analysis of the passenger flow distribution characteristics on the walking facility topology network is performed. The results show that when passenger flow density exceeds the density of free flow, congestion inevitably occurs in facilities with smaller capacities due to the actual passenger flow surpassing a certain threshold. The actual passenger flow distribution characteristics are influenced not only by the capacity of individual walking facilities but also by bottlenecks within the facility network. The research results provide data and technical support for station managers in developing and implementing flow restriction schemes.

To address the issue of not being able to provide an opencut receiving well at the receiving end of rectangular pipe jacking, this study analyzes the soil prereinforcement scheme used in the construction of rectangular pipejacking reception. It explores the appropriate structural type for the castinplace section of the abandoned shell and proposes a waterproofing scheme between the castinplace section of the abandoned shell, the precast pipe joints, and the hidden beams and columns of the station. t This study is based on the new entrance project of Jingjiang Road Station on Tianjin Metro Line 2. The processes, including the shutdown of the pipe jacking machine and grouting, are also optimized. Practical results show that the proposed scheme ensures the safe construction of the abandoned shell reception, with monitoring data indicating a maximum surface settlement of 12.12 mm. The key technology proposed in this paper are highly feasible and effective, offering a new design approach for similar projects, such as abandoned shell reception, where construction site limitations exist.

In response to the increasing operation and maintenance pressure and efficiency requirements of urban rail transit, a comprehensive management and control platform based on digital twins and multisystem integration is constructed and implemented to achieve intensive and refined operation and maintenance management of subway stations and improve management efficiency and service levels. Through 3D scanning of existing lines, this paper focuses on the development and implementation of an integrated management and control platform based on digital twin technology and multisystem integration, enhancing management efficiency and service quality. Firstly, a digital twin model is constructed to represent the operation of urban rail systems. The study explores model lightweight technology and uses 3D rendering engines to render and optimize large models and large scenes. In addition, this paper studies multisource heterogeneous data fusion technology through data standardize processing to realize the processbased collection and storage of heterogeneous data of various professions. Furthermore, a comprehensive urban rail management and control platform is developed, integrating functional modules to meet the needs of various disciplines. This platform improves the execution efficiency of operation and maintenance tasks by 30%, increases the accuracy of equipment and facility status monitoring to 98%, and increases the success rate of preventive maintenance by 20%. The efficiency of cross-disciplinary data sharing and collaborative work is enhanced by over 60%, resulting in a shortened fault response time, significantly improved accuracy of equipment and facility status monitoring, and enhanced effectiveness of preventive maintenance.

The Autonomous Train Operation System (TACS) is the development direction of future urban rail transit signal systems and is partly being applied in some urban rail transit. Different from traditional CommunicationsBased Train Control (CBTC), no unified TACS standard has been established yet. This paper aims to analyze the engineering applicability of existing TACS system degradation schemes. Based on the working principle of TACS, this paper discusses the necessity of configuring a degraded system. Drawing from the current development status of the TACS system, this paper summarizes three feasible TACS degradation schemes, introduces the architectures and working principles of different degradation schemes, and qualitatively analyzes the three TACS degradation schemes from the aspects of system composition, application scenarios, and tracking ability under degradation situation. The study establishes the train tracking time model under degradation situation, and simulates the degradation train tracking scenarios of three TACS degradation schemes under the same engineering conditions. Based on the simulation results, it identifies the factors that affect the efficiency of degradation tracking. Building on the above research, the key conditions for the TACS degradation system are summarized, and the engineering applicability and application effects of the three degradation schemes are analyzed, leading to several improvement suggestions. The results of this study have significant implications for the promotion and application of Train Autonomous Operation System.

In order to ensure personal safety, overvoltage protection devices (OVPD) are usually installed in stations and depots of operating lines. However, the overvoltage generated during the reset of the rail potential limiting device may cause the OVPD section II to act or even lock, resulting in the rail potential limiting device short circuiting the ground and rail, becoming a path for stray current leakage. With the continuous increase of urban rail operation mileage, stray currents have caused serious problems such as DC bias in the surrounding power system and corrosion damage to the urban pipeline network, which have seriously threatened the safe operation of the power system and oil and gas system. This paper proposes a suppression method for the overvoltage caused by the misoperation of the rail potential limiting device caused by abnormal rail potential, which exacerbates the leakage of stray currents in urban rail transit. The method involves constructing a simulation model of the overvoltage generated by the OVPD opening of the rail potential limiting device, constructing an arc experimental platform using N1250 contactors, and conducting grid mounted testing on actual lines. The results show that after using the overvoltage suppression method proposed in this article, the peak operating overvoltage generated by the opening of the rail potential limiting device is significantly reduced, reducing the possibility of OVPD misoperation and stray current leakage.

To promote the quality and efficiency of inventory areas in metropolitans, urban renewal of transit station areas in cityn centers presents an urgent challenge. By incorporating the Quality dimension into the traditional NodePlace model to indicate the perception of spatial environment, this study constructs the NodePlaceQuality Rubik's Cube state model to assess the renewal potentialof transit station areas in the downtown. Using Tianjin's central area as a case study, the modeling results show that the proportion of dependent and imbalanced types of transit station area is as high as 35.49% and 38.71%, respectively, while balanced and coordinated types account for 22.58% and 3.22%, respectively. The transit station areas with high renewal potential are concentrated in the edge of the Inner Ring of Tianjin, and the renewal potential of transit station under construction is also relatively high, while the transit station areas with low renewal potential are agglomerated in the central business district (CBD). These findings provide theoretical support and policy insights for the urban renewal in the transit station area in the metropolitan's downtown.

By the end of 2024, a total of 28 provinces and 58 cities in Chinese mainland have opened 362 urban rail transit lines, covering a total length of 12,168.77 km, including 9,281.37 km of subway lines, accounting for 76.27%. By the end of the statistical period, 1,486.01 km of Fully Automated Operation (FAO) lines have been opened, representing 12.21% of the total length of operational lines. In 2024, 51 new urban rail transit lines (sections) were added, with a total length of 953.04 km, including 738.26 km of new metro lines and 425.70 km of new FAO lines, all of which were classified as GoA4. It is expected that by the end of the 14th FiveYear Plan period, the total operating scale of urban rail transit in mainland China will exceed 13,200 km. It is estimated that the annual passenger volume at the end of the 14th FiveYear Plan period will double compared to the end of the 13th FiveYear Plan period.

To monitor rail health in realtime and provide early warning of rail fracture damage, this study proposes a broken rail detection method that combines ultrasonic guided wave detection and variational mode decomposition signal processing technologies. The system workflow and hardware circuits of each module were designed and constructed according to the requirements for rail fracture detection. A threedimensional rail model was created using finite element simulation software to analyze the propagation speed of ultrasonic guided waves within the rail and assess the feasibility of the noise reduction technique. The system's effectiveness was verified through equipment installation tests on Suzhou Metro Line 5, where artificially simulated rail fractures were used. The results demonstrated that, upon rail fracture, the system achieved a remote alarm time of 3 minutes and the defective positioning error is 1.1%, providing a reliable approach for rail fracture monitoring.

This study examines the impact of shield tunneling excavation speed and slurry solidification time on the buoyancy of tunnel segments, focusing on the section between Tongyuan Road Station and Xinggang Street Station on Suzhou Metro Line 5. A threedimensional finite element model of shield tunnel segments was developed using Winkler elastic foundation beams, considering the dynamic and static buoyancy effects generated by synchronous and secondary grouting on the pipe segments. The analysis assessed how excavation speed and grouting solidification time influence the uplift and misalignment of the segments. Results showed that both uplift and misalignment increased with higher tunneling speeds. The upward floating problem mainly occurs at the bottom of the pipe segment in the nonsolidified section of the slurry, whereas the misalignment mainly occurs at the junction between the nonsolidified section and the shield tail section, as well as between the nonsolidified section and the solidified section of the slurry. To avoid floating and misalignment of the pipe segments from exceeding the specification requirements, the excavation speed of the shield machine should not exceed 10 rings per day. Furthermore, it was observed that as the solidification time of the slurry increased, the amount of floating and misalignment of the tunnel segments gradually increased. Therefore, the use of a fastsetting and early strength dual liquid slurry is beneficial for controlling the floating of shield tunnels.