Development Of Rail Transit Research Articles

Greenhouse gas emission driving factors and reduction strategies for operational phase of urban rail transit in China

AbstractTo promote the sustainable development of urban rail transit (URT) in China, it is necessary to quantitatively analyze the greenhouse gas (GHG) emissions and its internal driving factors. Based on the LMDI algorithm, this research constructs an assessment model and makes a quantitative analysis of internal driving factors for GHG emissions in the operational phase of the URT system in China. According to the official investigated data, the GHG emission of URT in the operational phase is between 600 × 104 and 2000 × 104 tons of carbon dioxide equivalent (CO2e) per year from 2012 to 2023. The results of the driving factors decomposition showed that the passenger demand intensity was the key and positive factor affecting carbon emissions in the operational phase and the contribution rate was 12.93%–60.81% from 2013 to 2023. Therefore, it is necessary to formulate targeted policies in terms of management and technical means to reduce the average traveling distance demanded by passengers and reasonably control the scale of the line network for GHG reduction in the Chinese URT system.

First‐Principles Calculation of SnSe2 Material as Anode Material of Zinc Ion Battery

ABSTRACTThe development of high‐performance ion battery anode materials is conducive to the rapid development of urban rail transit. Based on first‐principles calculations, this paper studies the potential performance of the recently discovered two‐dimensional material SnSe2 as a negative electrode for zinc ion batteries. By calculating the adsorption energy, the most stable adsorption configuration of Zn was determined. The band gap of intrinsic SnSe2 decreases after strain, which promotes the transition of carriers. The band gap opens after the strain occurs in the Zn adsorbed SnSe2 system (Zn‐SnSe2), which confirms the regulation of strain on the band gap. The lowest diffusion barrier of Zn is 0.083 eV. The theoretical zinc storage capacity is calculated to be 387.550 mAh/g. The calculation results provide theoretical parameters for the application of SnSe2 in ion batteries.

The impact of heterogeneous accessibility to metro stations on land use changes in a bike-sharing context

The integration of urban rail transit and land use has been adopted as a crucial approach to fostering compact development in cities. Proximity to rail transit stations can increase the probability of land use changes, while few studies have analyzed the spatial heterogeneity of the impact of rail transit on land use changes. This study proposes a distance-decay function to delineate the spatial heterogeneity of metro station accessibility using bike-sharing data and examines the impact of metro stations accessibility on land use changes. Jiading New Town in Shanghai, China, is selected as our study case. By utilizing a non-linear distance-decay function to delineate metro station accessibility as a driving factor for training neural networks in a vector-based cellular automata model, an improvement in simulation accuracy is achieved compared to the model using a linear distance-decay function. This study could help establish more efficient strategies for promoting integrated development of rail transit and land use. The significance of this study lies in the generality of the optimized land use vector-based cellular automata model considering the spatial heterogeneity of metro station accessibility, which could also be applied to other situations, such as considering the accessibility to bus stops and road networks.

Research on Vibration and Secondary Noise Characteristics of Sensitive Buildings Along Metro Lines Induced by Metro Operation

With the rapid development of urban rail transit, the environmental vibration and secondary noise induced by metro train operation have become increasingly serious, posing stricter requirements on the vibration and secondary noise of sensitive building office (SBO) and sensitive building school (SBS). To predict and control the vibrations and secondary noise in sensitive buildings along the metro line induced by metro train operations. A prediction method for the vibration and secondary noise of sensitive buildings along the metro line during metro train operation has been proposed. The sub-model of train-track system coupled dynamics and the sub-model of track-tunnel-soil-building system dynamics are included. The influence of metro train operation on the vibration and secondary noise of SBO and SBS is studied. The influence of the distance between the metro line and the building on the vibration and secondary noise of the sensitive building is discussed, and an effective control scheme of vibration and secondary noise is proposed. Results show that the vibration frequencies of the SBS and the SBO caused by the metro train operation are concentrated at about 8[Formula: see text]Hz and 63[Formula: see text]Hz. The vibration below the second floor of SBO caused by the metro train operation exceeds the limit, and the secondary noise below the third floor of SBS exceeds the limit. The secondary noise inside the building of each floor of SBO exceeded the limit. Using secondary noise to evaluate the environmental impact of metro train operations is more stringent than relying solely on vibration assessments. secondary noise is recommended in engineering to assess the impact of metro train operation on sensitive buildings along line. Combined with vibration, secondary noise and construction requirements, SBS and SBO are recommended to be no less than 72[Formula: see text]m and 74[Formula: see text]m away from the metro line, respectively.

A Comprehensive Review of the Development Characteristics and Future Trends of TOD in Chinese Urban Rail Transit

The transit-oriented development (TOD) concept has become a significant catalyst for urban development in China, which has undergone rapid urbanization and has actively participated in the development of public transportation networks over the past 20 years. TOD not only guides the transformation of transportation modes but also leads the development of urban spaces. The extensive construction of urban rail transit in China highlights the universal patterns of TOD and reflects the uniqueness of Chinese practices. This paper analyzes the characteristics of urban development and TOD in developed countries, summarizing the common laws driving TOD in theoretical research. It then compares China, which is in a period of rapid rail transit construction, to identify the unique developmental laws of transit-oriented development of rail transit in China (TOD-RTC). The paper further examines the developmental characteristics of TOD-RTC in practice, considering both temporal and spatial aspects, and explores the reasons behind the formation of individual differences in TOD-RTC. Finally, it discusses the new value and potential that TOD brings to urban development, along with predicting future development trends.

Simulation and analysis of optimal energy-saving mode in microfield of underground rail transit

Underground rail transit has become one of the most popular transportation modes because of its advantages such as fast running speed, large passenger flow and punctuality. This mode of transportation can alleviate urban traffic congestion to a certain extent, so underground rail transit has been vigorously developed, and the number of rail lines has increased exponentially. However, with the continuous development of underground rail transit, the energy consumption of train operation is also increasing, resulting in a waste of energy. To solve this problem, this paper proposes to improve the energy-saving technology of train operation by using train autopilot control strategy. Firstly, a train operation optimization model considering train position and speed limit is established by using automatic train driving strategy, and the nonlinear problem of the optimization model is solved by genetic algorithm. The micro-field theory is introduced into the control strategy of automatic train driving, and the energy-saving model of underground rail transit is established. The energy consumption is optimized from three aspects: train energy-saving technology, line planning and overall operation planning of rail transit. The simulation results show that the average impact rate and energy consumption of trains under the proposed energy-saving model are significantly reduced compared with the other two groups of trains, and the average impact rate and energy consumption are significantly reduced compared with the other two groups of trains. The running time and energy consumption of the energy-saving model are lower than those of the experimental group. To sum up, the energy-saving model of underground rail transit proposed in this paper not only reduces the operating energy consumption, but also improves the passenger comfort, which can provide low-cost energy-saving technology for underground transportation field, and has positive significance for urban low-carbon development.

Rail Surface Defect Detection Based on Dual-Path Feature Fusion

With the rapid development of rail transit, the workload of track maintenance has increased, making the intelligent identification of rail surface defects crucial for improving detection efficiency. To address issues such as low defect detection accuracy, the loss of feature information due to single-path architecture backbones, and insufficient information interaction in existing rail defect detection methods, we propose a rail surface defect detection method based on dual-path feature fusion (DPF). This method initially employs a dual-path structure to separately extract low-level and high-level features. It then utilizes a combination of attention mechanisms and feature fusion techniques to integrate these features. By doing so, it preserves richer information and enhances detection accuracy and robustness. The experimental results demonstrate that the comprehensive performance of the proposed model is superior to mainstream algorithms.

The Feasibility of TOD Mode in Transportation Planning of Nantong City

The study examines the feasibility of the Transit-Oriented Development (TOD) model in the transportation planning of Nantong City. In the context of the "14th Five Year Plan for the Comprehensive Transportation System Development of Nantong City", it investigates the viability of the TOD mode within Nantong's rail transit system. This article will examine the successful TOD development cases in Shanghai, a first-tier city, and Suzhou, a new-tier city, both located in the Yangtze River Delta region. It will also compare the rail transit systems of Shanghai, Suzhou, and Nantong. Based on the current development status of rail transit in Nantong City, SWOT model is used to position the development of rail transit in Nantong City. hrough this analysis, this paper identified the advantages and disadvantages that Nantong City may face in advancing the TOD mode, as well as the potential opportunities and threats.Measures such as creating TOD channels, formulating ride discounts, expanding regional connectivity, flexible commuting time, and optimizing station facilities are proposed. hese strategies aim to promote the sustainable development of Nantong rail transit system, improve the convenience and efficiency of urban transportation, and then provide strong support for the economic and social development of Nantong city and the improvement of residents' quality of life.

Towards a collective opinion generation approach with multiple objectives for evaluating rail transit station accessibility in urban areas

Urban rail transit can alleviate traffic congestion if sufficient ridership is achieved. The accessibility to rail transit stations largely determines public willingness to utilize urban rail transit. The current studies on the accessibility to rail transit stations tend to concentrate solely on individual rail transit lines or stations, neglecting the impact of the external macro-environment. Consequently, the outcomes of these measurements cannot accurately reflect the overall accessibility level of the region, nor do they furnish decision-makers with references for devising plans for rail transit development. This study introduces a novel approach for evaluating the accessibility to urban rail transit stations from a macro-level standpoint, utilizing expert knowledge. The present study conducts an analysis of the impact of political, economic, social, and technological factors on the accessibility to rail transit stations in urban areas. Subsequently, a comprehensive evaluation indicator system is developed based on the aforementioned analysis. Then, experts are summoned to provide their subjective evaluations for every indicator, which are depicted as probability distribution functions. The collective evaluation is derived through the aggregation of individual evaluations utilizing a bi-objective optimization approach that factors in both the collective fairness utility and the confidence level. Finally, the quantile average method is employed to consolidate the collective assessment outcomes of individual indicators, thereby deriving the level of accessibility to rail transit stations in urban areas. We design a small-scale application experiment and attempt to evaluate the accessibility to rail transit stations in Wuchang District, Wuhan with the proposed approach in order to demonstrate the feasibility of the approach.

The Externality Impact of Urban Rail Transit on Urban Real Estate Prices in China

China has the largest and fastest growing urban rail transit system in the world. The system plays an important role in China's urbanization process, city governance and residents' daily commutes. The development of urban rail transit (URT) has influenced China's urban spatial structure and real estate supply, and has produced externalities on real estate value, including both positive and negative externalities. The research shows a positive correlation between URT and China’s real estate prices in general. The closer rail transit systems are, the greater the premium on real estate prices. In addition, the impact of rail transit on real estate prices shows a trend of first increasing and then decreasing. Different land use types and urban areas will also be affected. The research also found that the three stages of URT construction: planning, engineering construction and traffic operation have different effects on housing prices. At the same time, the impact of URT on land price will also change with China's economic situation and urbanization process. These influencing mechanisms above between URT and real estate prices may be linked to some factors. This research attempts to explain it by introducing urban spatial and land rent transformation, changes in real estate supply and demand, gentrification process, and different employment and housing pattern. This research points out the shortcomings and possible research directions of existing studies. In order to provide a reference for academic research and government policy making.

A Coupling Model for Measuring the Substitution of Subways for Buses during Snowstorms: A Case Study of Shenyang, China

The development of integrated public transportation networks has received widespread attention in recent years. Especially in global northern cities, improving the substitution of subways for buses could meet population travel demand during snowstorms, which minimizes the impact of snowstorms on the public transportation network. Furthermore, the development of rail transit is conducive to the intensive and efficient use of land resources. Therefore, in this study, we selected a northern Chinese city, Shenyang, as a case study. For obtaining the population travel demand, we collected the actual population flow data in the morning and evening peaks during snowstorms. The network analysis was used to identify the loopholes and key stations in the subway and bus networks, respectively. A coupling model was built to measure the coupling value of each station in the subway and bus networks, according to its population travel demand and supply capacity, which was further used to measure the substitution of subways for buses in the morning and evening peaks during snowstorms. The results indicate that some subway stations were in a coupling state, while their surrounding bus stations were in a decoupling state. These subway stations could replace the bus stations to reduce the impact and damage of snowstorms on public transportation network. However, some subway stations and the surrounding bus stations were all in a decoupling state, which were under great pressure to meet the population commuting demand during snowstorms. This study can provide insight into optimizing public transportation network planning and design in many northern regions and help to coordinate land and transportation utilization.

Analysis and modeling of radio propagation fading characteristics in tunnel construction

With the development of underground rail transit, the concept of intelligent tunnel construction has been proposed and promoted. High-quality networking during tunnel construction is a prerequisite for this, making it highly urgent to establish networking during tunnel construction. When studying intra-tunnel networking, it is necessary to consider the propagation characteristics of radio waves in the tunnel. In this paper, according to the actual needs of engineering in tunnel construction and the characteristics of tunnel scenes, an improved ray tracing method is proposed, which considers the type and installation position of antennas, transceiver frequency band and power in channel modeling, and proposes a field strength calculation method under different coordinate systems according to the characteristics of straight and curved segments during tunnel construction. In addition, the propagation characteristics of radio waves in dynamic tunnel construction scenarios are quantitatively analyzed. In this paper, by establishing antenna diagram, two-dimensional and three-dimensional models of tunnels, the computer simulation method is applied to compare with the improved algorithm, and the results have good consistency, in addition, the improved algorithm does not require a lot of modeling work in the early stage, and has high applicability and portability. Not only that, this paper also makes actual measurements of the subway under construction in Zhengzhou, China in different scenarios, and verifies the effectiveness of the method.

Application of improved axis theory based on spatial syntax in the planning of Xi’an urban rail transit network

This article mainly analyzes the Xi’an rail transit network by improving the axis theory. Through analysis, it can be found that the Xi’an rail transit network in three different stages has gradually developed from a chain and tree structure to a circular structure, and the rail transit has gradually improved. The passenger flow is basically proportional to the average integration degree of stations. From the perspective of average integration degree, the average integration degree of transfer stations is generally high, which plays an effective role in dispersing passenger flow. I hope that this study can provide some reference for the planning and development of rail transit in the future.

Prediction of short-term passenger flow of subway based on LSTM model

With the continuous development of urban rail transit, the subway is becoming the travel choice for more and more people. And the increase in travel demand also brings about the problem of subway congestion. This paper will use the subway card swipe data of Hangzhou City from January 1st to 20th, 2019, which were counted after data cleaning. With root mean square error (RMSE), mean absolute percentage error (MAPE), coefficient of determination (R^2), and loss values as standards, the long short-term memorys (LSTM) parameters were adjusted. The LSTM model is trained with time and passenger flow data, and the model is used to predict the short-term passenger flow in and out of subway stations. From the prediction results, the LSTM model has a good adaptability to the subway station short-term passenger flow. The trend of the predicted line is the same as the real value, and the difference is also controllable. The short-term passenger flow prediction of subway stations is beneficial to reduce the loss caused by congestion and improve the travel efficiency of residents.

A novel technique for constructing prefabricated subway stations under open excavation

Prefabricated construction is essential for realising green, efficient and sustainable development of rail transit. However, limited space in foundation pits and cross-interference with inner struts mean that the advantages of existing prefabrication technology cannot be leveraged effectively to build subway stations under open excavation with inner support. In this paper, this problem is addressed by introducing a modular design method and two novel connection technologies. The proposed modular design method is sufficiently adaptable to balance the use of space between the station structure and the inner struts. The two proposed connection technologies provide efficient ways to assemble different concrete segments with two newly developed joints – namely, a CHC joint (comprising two C-shaped and one H-shaped steel members) and a flexible lock joint – in the circumferential and longitudinal directions, respectively. The first application of this fully prefabricated scheme in the Shenzhen Metro shows the huge potential of this technology for constructing subway stations under open-cut conditions, and its advantages in technical, economic and social aspects reveal wide application prospects in rail transit.

Design and research of suburban railway fire alarm system

With the rapid development of suburban rail transit, fire safety issues have received more and more attention. As the first line of the Shanghai Suburban Railway, the fire safety problem of the Shanghai Suburban Railway Airport Link Line is more prominent. In this paper, an automatic fire alarm system is designed and researched for the fire safety problem of the Shanghai Railway Airport Liaison Line, which adopts a hierarchical distributed structure and can realize accurate fire detection thorough immediately sending fire alarm information to the station control room and line operation control center and informing the location of the fire area. At the same time, the system also coordinates with the BAS system and ISCS system or independently realizes the linkage control of fire fighting equipment. The research results of this paper are of great significance for improving the fire safety level of Shanghai railway airport links.

Parameter inversion analysis of rubber-mortar cohesive zone model in rubberized concrete

The rapid development of urban rail transit has brought convenience to travel, but also causes serious environmental vibration problems. Some scholars have proposed rubberized concrete invert-filling as a damping measure. The addition of rubber particles creates the rubber-mortar interface, which is an important factor that affects the damping performance of rubberized concrete. In this study, we propose an interface modification method of coating rubber with zinc stearate powder to improve the damping performance of rubberized concrete. The stiffness, strength, and fracture energy of the rubber-mortar interface were obtained by an inversion analysis technique based on numerical simulation and experimental results. The results show that: (1) The uniaxial tensile test determined the bonding strength of the rubber-mortar interface treated with water, sodium hydroxide, and zinc stearate as 0.144 MPa, 0.160 MPa, and 0.074 MPa, respectively. (2) Based on numerical simulations and experimental results, the bonding strength of the rubber-mortar interface treated by three methods was 0.142 MPa, 0.146 MPa, and 0.080 MPa, respectively, with relative errors of less than 10 %. (3) Compared with the interface obtained by water treatment, the interface modified by zinc stearate showed a 43.7 % reduction in bonding strength and a 46.0 % reduction in fracture energy.

Research on short-term passenger flow prediction method of urban railway based on machine learning

With the development of urban rail transit, the improvement of communication transmission technology, and big data processing level, the passenger flow data of urban rail transit continues to grow and can be effectively collected and stored, providing many basic data resources for analysis and passenger prediction research. With the development of artificial intelligence, short-term passenger flow prediction based on machine learning has received widespread attention. For this reason, based on the passenger flow data of Seoul Metro, this paper has carried out experiments and analysis on the existing models RNN-LSTM and ConvLSTM with better performance, providing theoretical support for short-term passenger flow prediction. The method in this paper solves the problem that a single traditional prediction model based on statistical theory is difficult to deal with large-scale complex data. It can complete the data processing task more accurately and efficiently, and has a good application prospect.

Stability Analysis and Safety Factors of the Excavation Face of a Pipe Screen Tunnel in a Soft Soil Area

With the rapid development of urban rail transit and underground space construction, the advantages of the concealed excavation method are gradually highlighted in the urban center area affected by a complex engineering environment. At present, the pipe curtain method with a flexible section and wide application of the soil layer is being widely used in engineering, but the research on the stability of the excavation face during the construction of the pipe curtain method in soft soil areas still has not formed a complete system. Therefore, this paper analyzes the stability of the excavation face under different reinforcement conditions and the influence of different spacing, numbers, and strength of MJS (metro jet system) zones on the stability of the excavation face of the pipe curtain method based on the actual project of the Guiqiao Road Station of the Shanghai Metro, China, and gives a reference for the reinforcement of the palm face in the excavation process of the pipe curtain method in soft soil areas. The study shows that the safety coefficient of the excavation face decreases with the increase in the slope angle of the excavation face, with the increase in spacing of the MJS zone, and with the increase in height of the MJS zone arrangement, while the safety coefficient of the excavation face increases with the increase in strength of the MJS zones themselves and the increase in the strength of the soil between the MJS zones. Further, the machine learning model is applied to predict the stability of the excavation face under different cases, and the relevant fitting accuracy is above 0.9, which can predict the stability of the excavation better.

Fault detection system of subway sliding plug door based on adaptive EMD method

With the rapid development of urban rail transit, the safety of subway sliding plug doors has become a great concern. To improve the operational reliability of the sliding plug door, we developed a fault detection system based on the adaptive empirical mode decomposition (AEMD). Firstly, we designed a hardware acquisition device and analysis software to collect motor current signal data during the opening and closing of the sliding plug door. Secondly, to address the impact of noise on signal analysis, the AEMD denoising method is proposed. This method employs EMD to obtain intrinsic mode functions (IMFs), and select the appropriate IMF components for reconstruction based on the adaptive threshold of Hausdorff distance, resulting in improved denoising effectiveness. Thirdly, waveform segments of different faults are sliced to reduce the amount of computation and effectively improve recognition accuracy. Meanwhile, this paper utilizes feature selection methods and machine learning techniques to classify the 12 subway sliding plug door faults. It is worth noting that most of these faults have not been extensively studied in previous classification research. The experimental results show that the identification accuracy reaches 98.96% on the practical platform. Moreover, the effectiveness and robustness of our proposed method are further validated through practical tests, ablation experiments, and comparisons with other relevant literature.