Transportation infrastructure in urban fringe areas is relatively underdeveloped, and the construction of rail transit will further impact the existing transportation system. It is necessary to optimize the planning and layout of land along the rail transit line around the rail transit station, and create an efficient and dynamic TOD community that integrates rail transit with urban functions and transportation systems, so as to realize rail transit leading urban development. Taking the Pingshan section of Shenzhen Metro Line 16 as an example, based on the TOD planning and design theory, the TOD planning method along the rail transit line is systematically studied from three dimensions: rail station, station area and station group. After the implementation of the plan, a rail development axis of “four complementary areas and two-center linkage” will be formed along Metro Line 16, with differentiated mixed sharing of land use at each rail station, fine ecology of block building, and efficient rail connection and integration, so as to realize the TOD planning and guidance along the subway line and enhance the agglomeration and carrying capacity of the areas along the rail transit.

To address the issues of wasted capacity during off-peak hours in urban rail transit and the increasing urban logistics demand alongside worsening traffic congestion, this paper proposes an online flexible train formation optimization model for mixed passenger and freight transportation in urban rail transit. The research first analyzes the feasibility and necessity of implementing freight services in rail transit systems. Subsequently, a mixed passenger and freight transportation optimization model with online flexible train formation is constructed based on Y-shaped lines, and solved using the GUROBI solver. Results indicate that the flexible train formation scheme for mixed transportation can effectively match capacity with demand, reduce the number of trains required, achieve efficient capacity utilization, and enhance economic benefits through freight revenue, thus providing new perspectives for urban rail transit development.

This study evaluates the coordination efficiency of urban public transportation systems by analyzing bus-subway transfer behavior characteristics, developing a bidirectional “subway-bus” transfer analysis framework based on Beijing's smart card data, which systematically defines subway-to-bus (STB) and bus-to-subway (BTS) transfer modes. An evaluation system encompassing 10 indicators—including transfer bus service area, competition intensity, and spatiotemporal distribution patterns—was constructed, with K-means clustering applied to classify subway stations. Key findings revealed that BTS transfers predominantly occurred during morning peaks while STB transfers concentrated in evening peaks, with both modes exhibiting a consistent 1:2 ratio in travel time and distance between bus and subway segments, alongside an average 6-minute bus waiting time for STB; spatially, high-demand bus transfers clustered around railway stations and sub-centers, with intense competition observed along the Tongzhou-Chaoyang corridor of Subway Line 1; clustering analysis categorized stations into five distinct types for each transfer mode, demonstrating tidal passenger flow-driven differentiation. The research provides theoretical and practical insights for optimizing transfer services and enhancing network coupling efficiency in megacities.

In view of the current problems of insufficient or excessive responses in flood disaster early warning and emergency management, a dynamic classification early warning evaluation for flood disasters has developed. Firstly, the early warning indicator system and quantification method for each warning indicator are developed based on the analysis of the disaster formation-prevention-resistance evolution mechanism of flood disasters in metro stations. The indicator system includes the risk of waterlogging and backflow, vulnerability, and disaster prevention and resistance capacities. Secondly, based on the relationship between hourly rainfall and meteorological warning levels with water accumulation depth, a quantitative method for assessing the risk of waterlogging and backflow in metro stations is proposed. Next, the evaluation methods of vulnerability and disaster prevention-resistance capacities are proposed based on the Analytic Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Finally, a comprehensive early warning value calculation method and warning level classification criteria for metro station flood disasters are established, and case verification is carried out relying on two actual metro stations. The research results show that this method can effectively achieve dynamic classification early warning on the basis of comprehensively considering the characteristics of subway stations and the flood disasters. The height of entrance and exit steps and the coverage rate of water level monitoring are the key factors affecting the early warning level. In practical applications, further attention should be paid to the real-time monitoring of data such as water accumulation depth and rainfall. The research outcomes can provide a decision-making support for advanced forecasting, early warning, and precise hierarchical response to flood disasters in metro stations.

The facade of the building is an important part of the image and urban style of the elevated station, and it plays a crucial role in the design of the station form. This research firstly analyzes the existing situation and problems of the facade of the elevated station through on-site investigation. Subsequently, the prefabricated construction technology is applied to the construction of elevated stations. The plasticity of concrete provides a new possibility for the innovation of the form design of elevated stations. On this basis, the design strategy of the station facade is put forward from the perspectives of design and construction respectively. In order to demonstrate the pertinence and effectiveness of the design strategy of the facade of the elevated station, the design practice is carried out in combination with the engineering projects of Dayanhe Street Station and Xiuhu Station of Zhejiang Jinyi East Urban Rail Transit. Finally, the organic balance between the diversity of station facade design and the standardization of assembled components is realized. The research results can provide important reference value and guiding significance for the design and construction of the facade of urban rail transit elevated stations.

To address the insufficient interdisciplinary collaboration and low efficiency in generating digital design outputs during the design process of subway station entrances and exits, and based on this, establishes a collaborative way of professional data of entrances and exits architecture and structure, and then develops a digital collaborative intelligent design tool for subway station entrances and exits based on general BIM design software. Finally, it takes the entrance and exit of a new subway station in Qingdao as an example for engineering application. The research results show that the collaborative intelligent design tool for entrances and exits has realized the functions of BIM model establishment and modification, 2D drawing generation and so on, which are needed by architectural and structural designers for 3D forward design of entrances and exits. Intelligent design tools digitally encapsulate the design experience of entrances and exits. After practical engineering application and statistical analysis, the design efficiency is improved by 2.7 times.

This study addresses public complaints regarding vibration and noise disturbances along an operational metro line with short-sleeper monolithic trackbed. Field investigations and measurements were conducted at both the metro track and sensitive receptor locations to analyze the root causes of these disturbances. Multiple mitigation measures were implemented, including the replacement of vibration-damping fasteners, rail profile adjustment, and rail grinding. The performance of floating rail fasteners was evaluated through vehicle-track coupling analysis and finite element modeling of the tunnel-soil-building system. Post-modification measurements and resident surveys were performed to assess the effectiveness of the implemented solutions. Results showed reductions in indoor vibration levels (VL_Zmax) of 6.4 dB during daytime and 8.3 dB during nighttime operations, while the equivalent sound pressure levels of structure-borne noise decreased by 1.36 dB (A) and 1.88 dB (A) for daytime and nighttime periods, respectively. Resident feedback confirmed significant improvements in the vibration and noise environment. This case study provides valuable insights for addressing similar vibration and noise issues in Chinese metro systems.

To investigate the feasibility of installing embedded rail tracks for trams on continuous beam bridges, an embedded rail track-bridge element model is proposed, and a static model of continuous welded rail (CWR) system is established for the bridge structure. The longitudinal forces and deformations of the CWR system under bridge temperature loads are analyzed. Using beam-rail relative displacement as the evaluation criterion, this study assesses the feasibility of CWR installation schemes and examines the effects of annual bridge temperature variation, longitudinal resistance of polymer materials, and rail expansion joint configurations on the mechanical behavior of the CWR system. Results indicate that the annual bridge temperature difference significantly affects both the beam-rail relative displacement and rail additional expansion force, exhibiting an approximately linear increase with temperature variation. Maximum values of both parameters occur at the right beam joint of the second continuous beam bridge. With an annual temperature difference of 30℃, the beam-rail relative displacement reaches 12.79 mm, exceeding the allowable limit of 6.20 mm. Since adjusting the longitudinal resistance of polymer materials proves insufficient to maintain displacement within limits, rail expansion joints are required. The installation of grooved rail expansion joints at the right beam ends of both the 11th and 19th spans is recommended to ensure acceptable beam-rail relative displacement.

To address the challenges of predicting the interaction effects of ground displacement and mitigating surface subsidence risks in double-line parallel shield tunneling, this study proposes a three-dimensional analytical method for displacement in unsaturated soil. Based on the initial solution for unsaturated soil under buried-depth loading, a three-dimensional analytical solution for ground displacement induced by double-line parallel shield tunneling is derived using the superposition principle, while comprehensively accounting for multiple influencing factors such as construction loads and soil loss. The validity and reliability of the proposed solution are verified through comparisons with real-world engineering cases. The results indicate that the longitudinal distance between tunnels and the transverse spacing of their axes significantly influence soil displacement: reducing the longitudinal spacing from 120 m to 0 m increases the peak total surface subsidence from 6.08 mm to 9.10 mm (a 50.0% increase); decreasing the transverse axis spacing from 1D to 9D reduces horizontal ground displacement by 49.2%; and lowering the depth-to-diameter ratio Z/D from 3 to 1 causes the peak subsidence to surge from 15.9 mm to 49.4 mm (a 210.7% increase), resulting in a deeper and narrower settlement trough. The study highlights that rational control of the longitudinal spacing of excavation faces, transverse axis spacing, and depth-to-diameter ratio is key to reducing surface subsidence risks during double-line parallel shield tunneling. The proposed analytical method offers a theoretical basis for optimizing construction parameters and mitigating subsidence risks.

To solve the joints at the interface between the main body and the ancillary structure of the subway station cannot be pre embedded with embedded waterproof components, the author and their team have developed a slot type polymer coated waterstop and its supporting products and construction technology. The internal core material of the waterstop is made of 1 mm thick steel plate pre processed into a “T” structure, surrounded by 1.2 mm thick polymer waterproof and anti-corrosion coating. Using matching fixing glue to fix the cold joint section, using matching “L”-shaped connecting plates and matching connecting glue to connect the waterstop into a ring, achieving the middle buried waterstop of the cold joint. This new waterproofing solution has been tested in the laboratory and proven to effectively solve the problem of interface cold joint leakage in underground projects such as subways and civil air defense in Beijing, Xuzhou, Zhoukou, and other areas. It has good promotion and application significance and can be used as a reference for similar projects.