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Red mudstone is a problematic soil that is easily subjected to weathering, disintegrating, and swelling. In this study, a series of large-scale cyclic triaxial tests were performed to investigate the cumulative deformation behavior of red mudstone clay mixed with weathered red mudstone gravel as an improved coarse-grained red mudstone soil (IRMS). The influences of compaction moisture content and confining pressure were investigated. The cyclic loading was applied from 25 to 225 kPa with an increment of 25 kPa and 1,000 or 2,000 cycles for each stage at a frequency of 2 Hz. The experimental results indicate that the strains at the onset of failure are approximately 1% for the optimal moisture content (OMC) with the number of cycles N = 14,000–16,000, and the strains are approximately 1% for the moisture content 2% dry of OMC with N = 12,000–14,000, while the strains exceed 10% for the moisture content 2% wet of OMC with N = 3,000–4,000. The cumulative strain decreases with increasing confining pressure from 20 to 50 kPa, but the influence becomes more significant under higher dynamic stress. A prediction model is proposed for the evolution of cumulative strain under cyclic loading. The IRMS could be used as a construction material for railway subgrade with proper control of field compaction moisture content. [ABSTRACT FROM AUTHOR]

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Copyright of New Architecture is the property of New Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT This paper proposed an approach to estimate disc cutter wear utilizing a combination of multiple operational parameters and vibration data collected during shield tunneling operations. The incorporation of vibration signals, notably those originating from acceleration sensors mounted on the back plate of the soil chamber, has markedly enhanced the accuracy of the model. Time‐frequency domain features were extracted through analysis methods such as Fast Fourier Transform (FFT), Short‐Time Fourier Transform (STFT), and Continuous Wavelet Transform (CWT). A predictive model utilizing vibration and shield operation parameters was developed using the XGBoost algorithm, and a deep GoogLeNet Convolutional Neural Network (CNN) was trained on time‐frequency graphs from the CWT. In addition, this study also investigated the impact of signal duration on wavelet image information and model accuracy. In the Huang‐Shang Intercity Railway Project, the approach effectively assessed disc cutter wear during tunneling operations and dynamically optimized the operational parameters of the shield tunnel machine through predictive analysis. [ABSTRACT FROM AUTHOR]

The rapid construction of high-speed railways in China has forced more and more routes to pass through slow subsidence zones caused by groundwater extraction or underground mining. It is crucial to carry out deformation monitoring and prediction those areas along high-speed railways to ensure the safe operation. Twenty-nine periods of Sentinel-1A data between Taiyuan South Station and Taigu East Station were first processed using the PS-InSAR technique, and the ground subsidence sequences at ten typical points were selected. Then the Variational modal decomposition (VMD) was combined with the Adaptive Boosting Algorithm (AdaBoost), and the VMD-LSTMAda-LSTMAda model was constructed by combining the long short-term memory (LSTM) model for the prediction of regional ground subsidence along the high-speed railway. The results show that the cumulative subsidence within the 200 m buffer of the line centreline is − 37.58 − 89.19 mm, and the annual average subsidence rate is − 26.57 − 82.63 mm/y. The proposed model can reduce the complexity of the deformation sequence and combines with AdaBoost to improve the prediction accuracy of the LSTM model. It performs well in terms of RMSE, MAE, MAPE, and R2 at the two feature points (3703: RMSE = 0.82 mm, MAE = 0.25 mm, MAPE = 6.31%, and R2 = 0.94; 522: RMSE = 1.32 mm, MAE = 0.46 mm, MAPE = 4.92%, R2 = 0.95). The model improves the accuracy of regional subsidence prediction along the high-speed railway. [ABSTRACT FROM AUTHOR]

The railway network connects different cities and regions and plays an important role in the transportation system. This paper theoretically analyzes the causal effect and mechanisms of the railway network on urban economic growth, and explores the direct effects, threshold effects, and spatial spillover effects of improved centrality in the railway network on urban economic growth in Northeast China. The results show that: (1) There is a similarity between the economic growth level and the trend of the railway network in Northeast China. From a spatial perspective, there are regional differences in the development of the railway network. (2) From the perspective of the direct effects, each unit improvement in railway network centrality leads to a 0.160 unit increase in urban economic growth in Northeast China. The degree of influence of other variables on urban economic growth, in descending order, is labor employment level, material capital investment, information development level, technological development level, human capital, and degree of openness. (3) From the perspective of the threshold effects of the railway network, the threshold values and the number of threshold levels are different for different regions. (4) There are significant spatial spillover effects in the railway network of Northeast China, and an increase in the centrality of a city's network can have negative spatial spillover effects on the economies of surrounding areas. Based on these results, we recommend that Northeast China should focus on the construction and improvement of the railway network, strengthen the connections between regions, and promote the overall economic growth of the region while improving its international competitiveness. [ABSTRACT FROM AUTHOR]

In this study, a distributed rail pad (RP) model of rail supported by double elastomer layers for rigid superstructures like light metro is presented, and a semi-analytical solution is derived via the Galerkin's method. Apart from existing distributed RP models that contain multiple individual spring-dampers, the proposed method offers locally continuous rail bedding. The new model assumes that the rail bedding is not pointwise and connects the continuous bedding and lumped baseplate mass with a derived function, which is the first novelty of the paper. Results of the single-spring model (SSM) and extended locally continuous support models (ELCSM) are obtained and compared to indoor and outdoor measurements in the time and frequency domains. The proposed model shows similar results to the conventional model for dynamic response; however, the clear difference between the models is seen at high resonant frequencies because of the stiffer bedding of the rail. Another point is that rail stresses and displacements can be calculated more accurately compared to SSM, due to including the length of RP. The findings of the study highlight the importance of considering RP length and stiffness when designing and maintaining railway tracks and provide insights into how to optimize these parameters for better performance and durability. [ABSTRACT FROM AUTHOR]

This article aims to provide an accurate mathematical model with the minimum number of degrees of freedom for describing the floating sleeper phenomenon. This was accomplished using mathematical modeling supported by extensive field measurements of the railway track. Although the observed phenomenon is very complex, the simplified single degree of freedom (SDOF) mathematical model proved accurate enough for its characterization. The progression of the deterioration of the railway track was successfully correlated to changes in the maximal dynamic factor for different types of pulse loading. The results of the presented study might enable the enhanced construction and maintenance of railroads, particularly in karst areas. [ABSTRACT FROM AUTHOR]

When the temporary backfilled subgrade is not sufficiently compacted, the result is low stiffness of the track system. Excessive deformation of railway tracks under the action of freight trains will aggravate track wear and reduce service life. However, traditional reinforcement technology to increase the stiffness of the track system is sometimes limited due to requirements of working space, efficiency, and little disturbance of the normal operation of the existing railway. Battered grouted helical piles (BGHP) are a kind of strengthening technology that has little influence on the existing railway and high construction efficiency. This paper presents a field case study of the implementation of BGHP to reinforce the freight railway subgrade. The paper evaluates the effect of the BGHP on the dynamic response of the treated subgrade. The subgrade soil was initially characterized by cone penetration tests at one location before BGHP reinforcement. The subgrade dynamic deformation modulus was measured before and after BGHP installation. In addition, the acceleration and velocity time histories of the subgrade were monitored during the passage of a freight train before and after BGHP reinforcement. The field measurement showed that the vibration acceleration, velocity, and displacement of the subgrade all decreased while the dynamic deformation modulus of the subgrade increased after BGHP reinforcement. Further, the vibration level reduced remarkably, mainly in the frequency band of 44.7 to 56.2 Hz, and the distribution of the normalized accumulated energy of velocity and acceleration was significantly influenced after BGHP reinforcement. The findings from this case study are of practical value to the emerging application of the freight railway subgrade reinforced by BGHP. [ABSTRACT FROM AUTHOR]

The rack railway system, driven by the meshing of vehicle gears and ground racks, overcomes the limitations of wheel-rail adhesion and offers advantages such as strong climbing ability, environmental sustainability, and low operational costs. These factors made it a key focus for rail transit construction in mountainous areas. The mountain rack railway system in China is still in its infancy, and technical standards for rack railway vehicles have yet to be fully established. Compared to traditional wheel-rail vehicles, rack railway vehicles exhibit significant differences. In order to clarify the particularity and top-level indicators of mountain rack railway tourism vehicles, this study analyzed the features of mountain tourist rail transportation. Based on the progress of domestic mountain rack railway tourism projects, the study identified specific vehicle requirements in terms of steep-slope operation, transitions between steep and gentle slopes, axle load, and sightseeing performance. The adaptability of meter gauge and standard gauge tracks in mountain tourism railways was studied, particularly how track gauge influences vehicle structure, clearance, and track structure. It was clarified that meter gauge tracks should be prioritized for routes with lower traffic volumes. A technical specification system was proposed, with three standard vehicle widths: 2. 65 m, 2. 5 m, and 2. 3 m. The corresponding vehicle dimensions and passenger capacities were specified. Train formations were proposed with capacities ranging from 486 to 7 320 passengers per hour. Additionally, an analysis of rack railway line characteristics indicated that the traction and braking performance of rack railway tourism vehicles should be between the levels of high-speed railway vehicles and urban rail transit vehicles. [ABSTRACT FROM AUTHOR]

With the rapid development of China's intelligent high-speed railway, the traction power supply system, as one of the key fields in intelligent equipment sector, has established a foundation for intelligence and digitalization. To further enhance the simulation and verification capabilities of the system, research on a digital twin traction power supply system was initiated. Taking the comprehensive data application throughout the entire lifecycle of the system from design to operation, this paper proposed the architecture and evolution path of the digital twin traction power supply system platform. Based on the functional characteristics of the system in the planning and design phase, this study analyzed the data fusion needs of BIM, power supply simulation, substation simulation, catenary simulation system and platform display interaction. A star-shaped data fusion topology was proposed, along with a data fusion method that constructed a unified dataset for data interaction. A unified dataset for structured data, BIM model and file-type data was designed, and a standard JSON data format for static and dynamic attribute data was proposed. A database was built to index and manage various types of data. Based on the Beijing - Tangshan intercity railway project, the digital twin traction power supply system platform was developed and explored in practical applications, achieving core functions such as BIM-driven simulation and three-dimensional dynamic visualization of simulation results, verifying the effectiveness of the data fusion method. This method will provide guidance for the intelligent construction, operation and maintenance of traction power supply system. [ABSTRACT FROM AUTHOR]

The determination of track plane design parameters plays an important role in the construction of testing and operational lines for rack railways. On the basis of the calculation principles of standard gauge railway lines, combined with the matching relationship between meter-gauge vehicles and tracks, a preliminary study on the key design parameters of the rack railway track plane was conducted using vehicle dynamics theory. By comparing with standard gauge railways and summarizing relevant parameter values from domestic and international specifications, the calculation formulas and control indicators of the curve radius and the transition curve length for the rack railway were obtained. The results showed that for a rack railway with a maximum design speed of 120 km/ h on adhesion sections and 40 km/ h on rack sections, the minimum curve radius for the adhesion section could be set at 900 m under normal conditions and 750 m under difficult conditions. For rack sections, the minimum curve radius could be 350 m under normal conditions and 300 m under difficult conditions. The transition curve length for adhesion sections should be selected according to the curve radius, while the minimum transition curve length for rack sections should be 20 m. [ABSTRACT FROM AUTHOR]

To further explore the load design parameters of ballastless tracks and provide theoretical support for the construction of high-speed railways operating at 400 km/ h and above in China, a study was conducted through static analysis of ballastless tracks and vehicle-track dynamic interaction under the excitation of the rail welds and wheel flats. This study revealed the characteristics and transfer patterns of static and dynamic loads from trains. Based on the load-bearing characteristics of the track and the design principles of ballastless tracks, suggestions for the vertical design load values of vehicles were proposed. The results showed that: (1) Rail weld irregularities and wheel flats could cause significant wheel-rail impacts on high-speed trains, with the maximum wheel dynamic load coefficient reaching 5. 79, which far exceeded the values specified in the current standards. The fastener system significantly attenuated the high-frequency component of the wheel-rail forces caused by wheel flats and rail weld irregularities, with the maximum dynamic load coefficient of fastener support reaction force reaching 2. 64; (2) The wheel-rail impact force caused by rail weld irregularities rose rapidly with train speed and the amplitude of the irregularities. It was suggested that the rail weld flatness standard for high-speed railways at speeds up to 500 km/ h should be 0. 2 mm/ m; (3) Wheel load was applied to the track slab through the fastener reaction force. Therefore, from the perspective of transfer characteristics, it was more reasonable to use the fastener reaction force as the vertical design load for the track slab, and a dynamic load coefficient of 3. 0 could meet the operation requirements of high-speed railways at speeds of 400 km/ h and above. [ABSTRACT FROM AUTHOR]

Groundwater exploitation is an important cause of land subsidence. A reasonable evaluation of the impact of land subsidence in groundwater exploitation area on railway engineering is of great significance for railway construction and operation. Taking the subsidence area of Heze-Lankao section of the Lunan high-speed railway as an example, and based on field surveys, a three-dimensional seepage-stress coupling land subsidence model was established using InSAR data and ground-level measurement data from May 2016 to July 2020 for model calibration. The model predicted and analyzed groundwater changes and land subsidence patterns in the next 15 years under different mining conditions. The results showed that the land subsidence along the railway was mainly caused by groundwater exploitation within a 200 m range on both sides of the line. Under current exploitation conditions, the influence radius of the subsidence funnel along the railway will continue to increase in the next 15 years. By 2035, the cumulative subsidence at the center of the subsidence area will reach about 200 mm, posing a severe threat to the normal operation of the high-speed railway. Closing the pumping wells within 200 m along the line can significantly mitigate the land subsidence risk, reducing annual subsidence by about 20 mm by 2035. [ABSTRACT FROM AUTHOR]

Major railway projects are large-scale, complex systems involving multiple stakeholders, and the risks during the construction process can be multifaceted and constantly evolving. To enhance the risk prevention and control capabilities in such projects, according to resilience theory, the study proposed a resilience management model based on risk prevention and control and outlined a framework for resilience construction management mode in major railway resilience construction projects. Using stakeholder theory, an integrated virtual organizational structure model for major railway construction was introduced. The resilience construction management mode combined organizational management and intelligent project management, embedding risk prevention and control into the organizational management system. This approach enhanced the resilience of organizational structure, strengthened its capacity to respond to risks and challenges, and leveraged intelligent technologies to boost collaborative capabilities. Additionally, the operational mechanism of resilience management was analyzed, which was governed by contractual, administrative, and trust-based relationships. The research results provide theoretical insights and decision-making strategies for risk prevention and control in major railway projects. [ABSTRACT FROM AUTHOR]

Intercity railways in urban agglomerations serve as critical transportation infrastructure, playing a key role in supporting and guiding the advancement of new urbanization in China. The functional orientation and technical standards of such railways have become focal areas of research within the industry. However, the current national railway technical standard system is insufficient to fully address the entire process of intercity railway construction and operation in urban agglomerations, particularly within the framework of "four network integration and interconnection". This study focused on the intercity railways in Jiangsu Province's urban agglomerations, with the goal of facilitating their integration into city centers and their operation as public transit systems. Based on their functional positioning and technical characteristics, and through comparisons with the national railway and urban rail transit standard systems, two major subsystems-engineering construction and transportation services-were constructed. Moreover, the system encompassed several key business areas, including foundation, surveying, design, construction, inspection, operation, management, and services. A standard framework, covering various specialized and thematic research areas, was established to guide the design, construction, equipment, inspection, and operational management of intercity railways in urban agglomerations. This framework aims to realize the vision of "unified planning, unified standards, coordinated operation, interconnection, seamless transfers, and one-ticket access." [ABSTRACT FROM AUTHOR]

Featured Application: The presented results are intended for inclusion in the national methodology for the economic evaluation of railway infrastructure projects. This contribution is focused on the presentation of individual research results aimed at evaluating the socio-economic impacts associated with increasing the safety and reliability of the railway transport route. The goal of the research is to propose and subsequently verify an original approach for assessing the impact of the implementation of investment projects, including measures aimed at increasing the safety and reliability of railway transport routes, on the resulting number of occurrences that happen on the railway in the Czech Republic. The proposed procedure is based on several key documents. In addition to already existing national methodologies, these are mainly the database of occurrences managed by the Railway Administration of the Czech Republic, including approximately 1000 occurrences for each year of the evaluated period (2009–2018), and information on 33 projects on the railway transport route, where the effects of their implementation on the overall frequency of occurrences are examined events in the subject location. The output of the research is a methodical approach for assessing the impact of the implementation of projects aimed at increasing the safety and reliability of the railway transport route. We perceive the impact on the occurrences from the point of view of the frequency of their occurrence and from the point of view of the socio-economic impacts that are achieved as a result of the implementation of the projects. From the point of view of the frequency of occurrence, a reduction in its value of 4.63% was found. As part of the research, the impact on the occurrence of extraordinary events is also assessed in the context of the scope of the railway transport route, both with regard to the length of the reconstructed track and also with regard to traffic performance. [ABSTRACT FROM AUTHOR]

The impact of karst collapses on railway engineering spans the entire lifecycle of railway construction and operation, with train loads being a significant factor in inducing such collapses. To study the dynamic response characteristics of subgrades in karst areas and to select appropriate monitoring points and indicators for long-term effective monitoring, a numerical simulation method was employed to analyze the vibration response characteristics of the subgrade. A three-dimensional finite element model coupling the high-speed train, ballastless track, and subgrade foundation was established to study the vibration responses of subgrades when the train passes over a subgrade with an underlying soil hole and one without a soil hole. The results indicate that when there was a soil hole, both the dynamic displacement amplitude and vibration acceleration amplitude decreased, while the dominant frequency slightly increased, with the dominant frequency being higher at locations closer to the soil hole. The vibration response at the soil hole location showed significant attenuation, with the attenuation coefficient of dynamic displacement amplitude being higher than that of the vibration acceleration amplitude. Monitoring points were arranged at positions 0 m to 10 m from the toe of the slope, with vertical dynamic displacement, vertical vibration acceleration, the dominant frequency of vertical vibration acceleration, and corresponding amplitude selected as monitoring indicators. These indicators effectively reflect whether soil holes exist within the subgrade and help identify the locations of defects. This study summarizes the dynamic response characteristics of subgrades in karst areas under different conditions, providing a basis for the design and monitoring of railway subgrades in regions prone to karst collapse. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to explore the psychological, emotional and equity implications of compulsory acquisition, evaluate the adequacy of compensation in mitigating those consequences and assess the sustainability of cash compensation for future generations. Design/methodology/approach: A case study approach was operationalised to investigate the experiences of 40 project-affected persons (PAPs) four years after a compulsory acquisition project in Ghana's New Akrade-Mpakadan region for the construction of a railway line. These perspectives were analysed through descriptive statistics and thematic analyses using the NVivo software. Figures and a holistic framework were adopted to report the identified issues. Findings: Overall, only 25% of PAPs received formal communication prior to the acquisition, and only 10.3% have been fully compensated four years later. Despite the acquiring body initiating the marking of properties and compensation assessment in 2019, no payments were made until 2021. This induced emotional responses of distress, loss, uncertainty, stress and sadness, which was further exacerbated by feelings of hopelessness because there was no platform to voice concerns or pursue arbitration. Although PAPs were only offered compensation in the form of single monetary payments, a third would have preferred re-settlement. Research limitations/implications: By exploring the emotional and psychological effects of compulsory land acquisition, the study adds a new dimension to understanding its consequences. This may spark more interest, debate and discourse amongst researchers and policymakers and lead to the creation or enhancement of existing policy and legal measures to address the needs of PAPs in compulsory acquisition projects in developing countries. Originality/value: The financial consequences of eminent domain are well documented, but this study explored the psychological, emotional and equity implications of the practice under conditions of weak regulatory frameworks. The adequacy of single lump-sum compensations was also explored to highlight preferred alternatives to ensure fairness for generations unborn. [ABSTRACT FROM AUTHOR]

Purpose: This research aims to propose a model for the complex decision-making involved in the ecological restoration of mega-infrastructure (e.g. railway engineering). This model is based on multi-source heterogeneous data and will enable stakeholders to solve practical problems in decision-making processes and prevent delayed responses to the demand for ecological restoration. Design/methodology/approach: Based on the principle of complexity degradation, this research collects and brings together multi-source heterogeneous data, including meteorological station data, remote sensing image data, railway engineering ecological risk text data and ecological restoration text data. Further, this research establishes an ecological restoration plan library to form input feature vectors. Random forest is used for classification decisions. The ecological restoration technologies and restoration plant species suitable for different regions are generated. Findings: This research can effectively assist managers of mega-infrastructure projects in making ecological restoration decisions. The accuracy of the model reaches 0.83. Based on the natural environment and construction disturbances in different regions, this model can determine suitable types of trees, shrubs and herbs for planting, as well as the corresponding ecological restoration technologies needed. Practical implications: Managers should pay attention to the multiple types of data generated in different stages of megaproject and identify the internal relationships between these multi-source heterogeneous data, which provides a decision-making basis for complex management decisions. The coupling between ecological restoration technologies and restoration plant species is also an important factor in improving the efficiency of ecological compensation. Originality/value: Unlike previous studies, which have selected a typical section of a railway for specialized analysis, the complex decision-making model for ecological restoration proposed in this research has wider geographical applicability and can better meet the diverse ecological restoration needs of railway projects that span large regions. [ABSTRACT FROM AUTHOR]

Purpose: The mega railway infrastructure projects are faced with complex environments and multi-level management challenges. Thus, the mega railway infrastructure project management system not only needs to focus on its composition, but also needs to consider changes and impacts of internal and external environment. Design/methodology/approach: This study attempts to introduce the concept of dissipative structure from the perspective of complexity theory and constructs a positive entropy and negentropy flow index system for mega railway infrastructure project management system in order to analyze the factors of management system more deeply. The Brusselator model is used to construct the structure of the mega railway infrastructure project management system, and the entropy method is used to calculate the positive entropy and negentropy values to verify whether the management system is a dissipative structure. Findings: A plateau railway project in China was used as an example for an empirical study, not only its own characteristics are analyzed, but also the role of constraints and facilitation of the internal and external environment. Based on the research results, several effective suggestions are put forward to improve the stability and work efficiency of mega railway infrastructure project management system. Originality/value: This study demonstrates that mega railway infrastructure project management system has the characteristics of dissipative structure. It can provide theoretical support for the development of mega railway infrastructure project management system from disorderly state to orderly state. [ABSTRACT FROM AUTHOR]

Translation abstract Comparison of the CO2 balance for maintaining and new construction of railroad bridgesAs soon as energy is used for a certain activity, emissions are inevitably generated as part of negative CO2 emissions. Alongside many other sectors, the construction industry is one of the biggest drivers of the ongoing negative balance. A rethink towards the continued use of load‐bearing structures in structural engineering can be a potential driving force here. Compared to the proportion of existing arch bridges in the Deutsche Bahn network, the existing durability of these structures and the associated residual load‐bearing capacity, a successful saving can be demonstrated with regard to ecological and economic goals, as well as the renovation of existing building culture at the current times of use of current reinforced concrete structures. The CO2 balance presented here for the use of building materials, dismantling, the creation of construction site facilities, the movement of earth masses, rail replacement traffic during the construction period and the operation of the facilities over a service life of 120 years illustrates the potential that the preservation of arch bridges offers compared to new construction. With a view to the upcoming construction measures for the arch bridges and Deutsche Bahn's goal of achieving climate neutrality by 2040, this type of construction can be a step in the necessary direction. [ABSTRACT FROM AUTHOR]

Tunnel stability is influenced by the rheological properties of the surrounding rock. This study, based on the Ganshen high-speed railway tunnel project, examines the rheological characteristics of siltstone and sandstone through laboratory tests and theoretical analysis. Rheological curves and parameters are derived, revealing the time-dependent deformation mechanisms of the surrounding rocks. A numerical simulation model is created using these parameters to analyze deformation and stress characteristics based on different rock levels and inverted arch closure distances. Results indicate that sandstone follows the Cvisc model, with the Maxwell elastic modulus increasing under higher loads while the viscous coefficient decreases. The vault displacement is mainly affected by the surrounding rock strength; lower strength leads to greater displacement, which also increases with the closure distance of the inverted arch. These findings are crucial for determining the optimal closure distance of inverted arches in sandstone conditions. [ABSTRACT FROM AUTHOR]

The sudden inrush of water poses a serious threat to the safety of workers during tunnel construction in the karst region of southwest China. To mitigate this risk, a model is proposed to assess the risk of water surge through a tunnel by combining improved game theory with uncertainty measure theory. Eight indicators of risk were extracted based on the solubility of rock, its geological structure, capacity for surface catchment, and hydrogeological factors, and were incorporated into the proposed model. The subjective weights of these indicators were obtained using the analytic hierarchy process, while their objective weights were calculated through the entropy weighting method and the criteria importance through intercriteria correlation method. An improved game theory-based method of combinatorial weighting was then used to construct the corresponding weight vectors. Single-indicator measurement functions and multi-indicator measurement matrices were utilized to classify and evaluate the indicators of the risk of a surge in water level based on a confidence criterion. The proposed method was applied to five typical karst sections of the Yanjin Tunnel of the Chongqing–Kunming High-speed Railway Project, and the method was validated by comparing the recorded and estimated inflow volume ranges during the project's construction, showing consistency with the actual evaluation results. This proposed model thus offers a practical tool for assessing the risk of water inrush in karst tunnels. [ABSTRACT FROM AUTHOR]

With the increasingly emerging traffic intersection form of high-speed railways passing underneath integrated transport terminals, the ground vibration induced by trains running on underground high-speed railways has attracted extensive attention. In combination with the engineering example of a high-speed railway in construction passing underneath an airport, the wheel-drop impact test in the high-speed railway tunnel was designed to obtain the vibration characteristics of surrounding soil. The vehicle-track-tunnel-ground semi-analytical three-dimensional model was established to determine the initial dynamic load condition of the vehicle loads. The amplitude-frequency characteristic and transmission law of the ground vibration induced by trains running on underground high-speed railways were predicted and analyzed. The influences of different operation conditions, track parameters, and tunnel burial depths were compared. The research results show that the ground vibration obtained through the wheel-drop test is greatly attenuated within 10 m from the track centerline, with an attenuation rate up to 70%. The vertical vibration amplitude is obviously larger than that of the other two directions. The lateral ground vibration amplitude is the smallest with the slowest vibration attenuation speed. When the high-speed train passes through at the speed of 350 km/h, the vertical and lateral vibration levels of the ground surface within 80 m range are 20∼80 dB and 43∼72 dB, respectively. The maximum attenuation coefficient of Z-vibration level reaches 0.276 dB/m. For each increase of 50 km/h of the train speed, the Z-vibration level of the ground increases by about 2 dB. The smaller fastener stiffness leads to the greater ground vibration within 20∼50 Hz. The ground vibration level is positively correlated with the fastener stiffness above 79 Hz. When the burial depth of the tunnel is greater than 14 m, the burial depth of the tunnel has little effect on the change of the Z-vibration level of the ground. [ABSTRACT FROM AUTHOR]

Rolling stock manufacturers are finding innovative structural solutions to improve the quality and reliability of railway vehicle components. Structural optimization processes represent an effective strategy for reducing manufacturing costs, resulting in geometries that are easier to design and produce combined with innovative materials. In this framework, the present paper proposes the development of a design methodology to innovate a railway bolster beam using topological optimization techniques, assessing the effect of different manufacturing constraints oriented to the casting process. A comprehensive numerical testing campaign was conducted to establish an effective testing procedure. Two different designs were obtained and compared, statically and dynamically, evaluating the difference in terms of mass, mechanical performance and manufacturability. Reductions in stress values up to 70% were observed, along with an 8% increase in the first natural frequency of the component, leading to beneficial effects in terms of stiffness. The methodology shows encouraging results to streamline the design of complex casting components, moving to a new generation of structural railway components. [ABSTRACT FROM AUTHOR]

Effective supply and demand matching for construction materials is a crucial challenge in large-scale railway projects, particularly in complex and hazardous environments. We propose a two-stage stochastic programing model that incorporates environmental uncertainties, such as natural disasters, into the supply chain optimization process. The first stage determines optimal locations and capacities for material supply points, while the second stage addresses material distribution under uncertain demand. We further enhance the model's efficiency with Benders decomposition algorithm. The performance of our model is rigorously compared with existing optimization approaches, demonstrating its superior capability in handling environmental uncertainties and complex logistical scenarios. This study provides a novel framework for optimizing supply chains in challenging environments, offering significant improvements over traditional models in both adaptability and robustness. [ABSTRACT FROM AUTHOR]

China accounted for 14.4% of the global exports of goods, ranking first in 2022, followed by the United States at 8.3%. As the United Nations Conference on Trade and Development commented, China has become a global trade titan, and its meteoric rise as perhaps one of the best stories of economic development has been both admired and questioned. This article discusses the reasons behind China becoming a global trade titan from the perspective of transport logistics by applying statistical analysis and case studies. The results show that the meteoric rise of China's trade is inseparable from China's development in transport logistics, especially investments in maritime transport construction and China Railway Express, which hugely promote the interconnectivity of transport infrastructure and reduce transportation duration and waiting time, especially during the COVID-19 pandemic. Furthermore, the imbalance of types of imports and exports in trade and the differences in infrastructure standards pose some problems. The research manages to give policy implications based on the existing problems of the current trade logistics system through case studies on Sino-US, Sino-EU and Sino-ASEAN trade relations and transport facilitation issues. [ABSTRACT FROM AUTHOR]

To address the challenges of effectively managing and professionally utilizing massive geospatial data in the railway surveying process, this paper presented an automated management and publishing method based on the ERDAS APOLLO spatial GIS engine. By integrating the characteristics of data at various stages of railway surveying, a standardized process for data organization, storage, processing, and sharing was established. A method for collecting and verifying railway geospatial metadata was developed, enabling rapid data entry and attribute acquisition for railway geospatial information. A system architecture with separate data, service, and application layers was designed in a B/ S (Browser/ Server) mode for the distribution and display of multi-source geospatial information. Utilizing Asp. Net, Vue. js, and the Cesium mapping framework. A railway multi-source geospatial data management system was developed in a front-end and backend separated architecture, achieving unified data management and shared application. A survey project with a total data volume exceeding 600 GB was selected as a case study to verify the system's capabilities in data management, checking, verification, and visualization. The research indicates that the automated data management and service publishing process significantly reduce the costs associated with data storage, processing, and maintenance. The integrated map and attribute approach enhances the efficiency of data retrieval and increases the value of data utilization, effectively serving the application needs of the railway design profession for geospatial information data. [ABSTRACT FROM AUTHOR]

Automatic monitoring is an important means to ensure the safety of high-speed railway operation during the construction period of adjacent high-speed railway projects. However, the installation of monitoring equipment on the trackside may have a certain impact on the safety of high-speed railway operation. This paper used the aerodynamic calculation method in the Code for Design of High-speed Railway and the calculation method of internal force of anchorage connection and the limit state of bearing capacity in the Technical Specification for Post-Installed Fastenings in Concrete Structures to calculate and analyze the impact of aerodynamic effect on the total station, protection box and monitoring prisms 3.5 m away from the line centerline on the roadbed under the condition of 350 km/ h train speed. The calculation results show that under the influence of high-speed railway aerodynamic effect, the expansion bolts of the total station, protection box and monitoring prisms bear less tensile and shear forces than the design values of the bolt steel failure tensile and shear bearing capacity. The tensile forces borne by the anchor foundation concrete are all less than the design values of the concrete cone failure tensile bearing capacity, meeting the requirements of the specifications. [ABSTRACT FROM AUTHOR]

The double block concrete sleeper is the most used prefabricated components in Chinese high-speed railway construction. At present, it is mainly produced by assembly line prefabrication. The traditional manual inspection method cannot fully satisfy the requirements of the double block sleeper. In order to solve the problem of high accuracy requirements and heavy inspection tasks, this paper proposed a double block sleeper shape and appearance quality automatic inspection system based on high-precision 3D laser scanner and highresolution industrial camera. The inspection system was integrated with production line, so that the inspection system was automated operated online with inspection function. This paper researched the automatic acquisition technology of 3D point cloud and high-definition image of double block sleeper, 3D point cloud analysis and processing technology of double block sleeper, images analysis and processing technology of double block sleeper. Through point cloud segmentation and model reconstruction algorithm, the key components model of double block sleeper was obtained, automatic detection of the shape dimensions was realized. Through image template matching and image deep learning algorithm, intelligent recognition of sleeper numbers and cracks was realized. The inspect accuracy of the system can reach 0. 1 mm, the detection efficiency is better than 3 minutes/ group, the crack recognition accuracy is better than 95%, and the detection items and accuracy meet the relevant specifications. The system has the characteristics of automation, real-time, high precision, and high efficiency, can effectively solve the quality control problems of double block sleeper prefabricated factory [ABSTRACT FROM AUTHOR]

Due to the non-standardization and the personalized need of thematic mapping, the processing efficiency of basic geographic information data has not been effectively improved. The thematic mapping technology based on Photoshop has been adopted in railway industry widely. This paper applied the JavaScript technology to the secondary development of mapping, called the API of Windows and Photoshop, and used common mapping modules, mapping functions, main parameters, and hotkeys to encapsulate packages. It realized batch processing of remote sensing images, automatically processing of features on thematic map, and modification of map features in human-machine interaction manner. The research includes three parts: (1) The introduction of the configure environment, compile platform, and result of secondary development based on Javascript. (2) The application of four application scenarios for JavaScript technology: 1 Image batch processing to achieve automatic spectral enhancement of remote sensing image. 3 Automatic mapping for thematic map elements. 2 Batch and automatic modification of features on maps. 4 processing of elements on the map in human-machine interaction manner. (3) The example of the thematic mapping of a railway project in Europe using remote sensing image for the verification of the feasibility. The results show that the technology can significantly improve the mapping efficiency, make it easier to standardize drawing map symbol, and solve the problems on high redundancy of data and low efficiency of execution during batch and automatic processing scripts. [ABSTRACT FROM AUTHOR]

In order to solve the problems of low work efficiency, poor measurement accuracy, and high safety hazards of traditional surveying and mapping techniques in railway construction in high-altitude areas, by using a vertical fixed-wing UAV flight platform equipped with an oblique photography camera, a complete aerial photogrammetry technology workflow was established based on the terrain characteristics and survey requirements of high-altitude areas. The use of UAV oblique photogrammetry technology to complete railway field survey work could effectively reduce the field workload of railway survey in high-altitude areas. From the comparison and analysis of checkpoint data, it can be seen that the MSE in the plane of the checkpoint is 0.06 m, and the MSE in the elevation is 0.12 m, which meets the accuracy requirements of topographic maps and real scene 3D models. The research results indicate that UAV oblique photogrammetry technology can provide production projects with high-definition images, terrain map data, and 3D models. UAV have advantages such as mobility, flexibility, and are not limited by terrain and features, which can improve production efficiency, reduce operating costs, and significantly reduce safety hazards in high-altitude areas. [ABSTRACT FROM AUTHOR]

In order to improve the efficiency of railway track profile measurement and reduce the safety risk, combined with the speed-up renovation project of an existing conventional railway in western China, this study adopted vehicle-borne lidar technology to improve the accuracy of vehicle-borne lidar elevation measurement from the aspects of system equipment selection, vehicle-borne lidar configuration, encryption of leveling control points and optimization of GNSS measurement scheme. The measurement scheme was constructed and the scanning of track and railway structures was carried out. Then, through point cloud matching, the corresponding relationship between the WGS84 linear coordinates collected by the feature point radar and the construction coordinates of the feature points collected by RTK was established, and the mathematical model of coordinate transformation was constructed. The model was used to map the coordinate space of the point cloud to the independent space coordinates of the designed railway construction project. Then, the track coordinates and elevation information were extracted by software, and the linear measurement of the railway track by the vehicle-borne lidar technology was realized. The results show that based on the vehicle-borne lidar scanning, the railway track profile measurement of the capacity expansion railway is encrypted to about 500 m according to the fourth-order leveling accuracy spacing along the leveling point. The elevation accuracy is conditionally controlled within 2 cm, and the elevation, 100-meter standard measurement and dialing distance acquisition quality can meet the accuracy requirements of the railway track profile measurement of the capacity expansion railway. [ABSTRACT FROM AUTHOR]

Railway surveying is one of the important tasks in China's railway construction engineering. Through the unremitting efforts of several generations of railway surveyors, Chinese railway surveying technology has evolved from pure manual surveying and mapping at the beginning of the founding of the People's Republic to the current state of digitalization and automation, and is advancing towards intelligent surveying. This paper systematically summarized and reviewed the development history of surveying techniques in Chinese railway surveying process, including primary control surveying, 1:10 000 topographic mapping, 1:2 000 topographic mapping, centerline surveying, cross-section surveying, site topographic mapping, and existing railway surveying. It also studies the use of UAV LiDAR technology for special surveying tasks such as centerline and intersection surveying for new railways, achieving precision that meets the 10 cm limit requirement. New methods for conducting various surveying tasks on existing railways based on mobile laser scanning technology and UAV oblique photography surveying technology were introduced. The surveying precision essentially meets the requirements for existing railway centerline surveying with a planar detection limit difference of no more than 3cm and a general terrain elevation detection limit difference of no more than 5 cm. [ABSTRACT FROM AUTHOR]

In response to the current lack of universal Lambert projection coordinate transformation and length deformation calculation software, this article summarized the Lambert projection formula and developed a Lambert projection coordinate calculation software. Taking a high-speed railway project in Morocco as an example, this paper compared the coordinate transformation results of the software with those of EPSG and a certain Gaussian coordinate transformation software. At the same time, the length deformation of the Lambert projection for this project was calculated, and the law of length deformation was analyzed. The calculation results indicate that, the software can achieve the calculation of Lambert projection coordinates with different parameters. The calculation accuracy of the software in this paper can be accurate to four decimal places, meeting the needs of Lambert projection zone change calculation. The calculation results of length deformation show that, when there is no undulation on the ground, both the Lambert tangent projection and the Lambert secant projection can control the length deformation within ± 10 mm/ km in the area with a latitude difference of 0.7°, which means that in the absence of undulations on the ground, the length deformation control ability of the two projections is the same. The establishment of an engineering independent coordinate system using the Lambert tangent projection with simple deformation patterns is suggested for priority use. [ABSTRACT FROM AUTHOR]

The UK's "Restoring Your Railway" (RYR) programme aims to reopen abandoned railway infrastructure to foster local economic growth. However, since 2020, only 30% of RYR proposals have progressed, revealing challenges in the methodological approach, especially for projects introducing rail as a new mode. The current unimodal approach for estimating user benefits in such projects is considered inadequate. To address this, a Cost-Benefit Analysis (CBA) with improved methods for user benefit estimation has been conducted, compared with existing cases to determine if it results in a better Benefit-Cost Ratio (BCR). Historically, early appraisal methods relied on the Strategic Outline Business Case (SOBC), which took six months and incurred costs of approximately Rp. 1.5 billion. To expedite project delivery, sensitivity analysis explores circumstances under which RYR projects are socially justifiable across different Value for Money scenarios. Additionally, a comparative analysis is performed between the UK and Indonesian approaches. This study introduces a new CBA approach, focusing on user benefit estimation and conducting sensitivity analysis on key determinants. The mathematical CBA model, modified for the value of time and diversion factor, forms the basis for sensitivity analysis on BCR, travel time savings, capital and operational costs, diversion factor, and GDP growth. Testing the model against business cases reveals a 17-20% reduction in the required demand for the same BCR compared to conventional CBA approaches, suggesting the new method captures additional benefits related to mode shifts. Sensitivity analysis highlights circumstances under which railway projects are likely to deliver acceptable value for money, considering various BCR values. Total order indices show that operational costs contribute 40% to the model output, followed by capital costs and GDP growth rate at 29% and 25%, respectively. Surprisingly, the In-Vehicle Time (IVT) for trains has only a small contribution, ranging from 1.83% to 4%. [ABSTRACT FROM AUTHOR]

To calculate the surrounding soil pressure applied to shallow underground structures in layered soils, a new calculation method suitable for shallow underground works in layered soil is proposed by introducing the horizontal slice method (HSM). Through comparison with traditional methods and measured data, the rationality and accuracy of the proposed method are demonstrated. Model parameters, model assumptions, and limitations of the proposed method are also discussed. The research results find that the vertical soil pressure obtained from the proposed method is close to the results of Bierbaum's theory and method in the Chinese "Code for Design of Railway Tunnel", all showing a linear growth trend, but the lateral earth pressure derived from the proposed method shows a nonlinear distribution. The vertical pressure is linearly positively correlated with internal friction angle, cohesion, and burial depth, while it is linearly negatively correlated with the equivalent friction angle. The lateral earth pressure decreases with an increase in the internal friction angle and cohesion at the same depth, while it increases with an increasing equivalent friction angle. For layered soil, lateral stress undergoes abrupt changes of different degrees at the soil layer boundary and the burial depth boundary. [ABSTRACT FROM AUTHOR]

Could the connectivity of a global railway network increase through small changes in the timetable services? When designing railway schedules, transfer connections to intermediate stations may not be the primary focus considered. However, they may have an important influence on connectivity. In this paper, we study the potential improvement in connections by introducing small changes to the current schedules, using real timetables from all international railway services in Europe. The modelling was completed using the Complex Networks methodology and performance was measured based on total closeness centrality. Various factors are considered to calibrate the necessary amendments to provide a better traveller service, including connection times at stations and different allowed levels of schedule changes. The results indicate that by changing the schedule of only 1% of the services by at most 10 min, the connectivity improvement is remarkable. Railway companies should consider this result in order to expand the potential use of the international railway service at a time when public transportation must be encouraged. [ABSTRACT FROM AUTHOR]

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Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

According to EU policy goals, railway shall become the main pillar of a sustainable and smart mobility. This works outlines how the environmental sustainability of railway vehicles can be further improved by integrating Life Cycle Assessment (LCA) in the simulation-based design process of lightweight railway vehicles and by considering environmental sustainability as an equal criterion for the design optimisation. The LCA for lightweight railway vehicles considering the manufacturing, operation and recycling phases is performed using a LCA tool. To link the LCA tool with the simulation-based development process of the vehicle, an interface is implemented. Process and vehicle parameters coming from the development process as well as datasets from LCA databases are used to parameterize the LCA model. By applying local and global sensitivity analyses, the most influencing design parameters with respect to the environmental impact can be identified and the effect of uncertainties studied. Based on the results, the environmental sustainability of the vehicle design can be optimised. The development process including LCA is illustrated for the application case of a railway vehicle bogie, exposed to high loads and design requirements. Different design configurations based on steel and carbon fibre composites are compared. For the assumed energy supply, it is the found that reduction in energy consumption during the operation phase overcompensates for energy-intensive production and recycling of carbon fibre composites. [ABSTRACT FROM AUTHOR]

In recent years, the construction of new railway tunnels worldwide has become increasingly challenging due to larger cross-sections, deeper burial depths, higher in situ stress, and more complex geological conditions. During both construction and operation, some tunnels have encountered significant issues with floor heave. This paper begins by identifying the primary causes of deformation and instability in tunnel floor structures through an investigation and statistical analysis. It then examines floor heave across more than 20 railway lines, summarizing the types, generation mechanisms, and mechanical models associated with this issue. Additionally, extensive survey data indicate that tunnel floor heave is most likely to occur in gently inclined thin-layered rock masses. Therefore, using a tunnel passing through the plate suture zone in such a rock mass as a case study, numerical simulations, theoretical analyses, and on-site monitoring were conducted. This study systematically analyzed the influence of single and multiple factors, as well as the mechanical behavior of the support system, on tunnel floor heave in gently inclined thin-layered surrounding rock. Furthermore, several key models were proposed: a tunnel floor heave estimation and load formula based on a mechanical model, a dynamic relationship between surrounding rock support force and tunnel floor heave using the Nishihara model, a tunnel floor settlement estimation formula based on deformation statistics, and a tunnel floor heave energy prediction model utilizing the B-P neural network algorithm. These conclusions have been validated and widely applied in practical engineering, providing a robust theoretical foundation and technical support for future tunnel construction. [ABSTRACT FROM AUTHOR]

Market liberalization reforms in China have led to greater domestic market integration. However, significant urban-rural price differences suggest that segregation between urban and rural markets persists in China. We study the evolution of price differences between urban and rural areas across 25 Chinese provinces over the period 1985-2020. Firstly, we record a substantial and persistent gap between urban and rural price levels within each province. Secondly, we find that this gap narrowed after China implemented the Price Law, which is suggestive of deeper urban-rural integration associated with policy changes. Additionally, we observe notable differences in urban-rural price gaps between provinces, however, using the log-t test, we find evidence of regional convergence in these price gaps. Finally, we investigate the impact of transport infrastructure development on urban-rural price differences. Using spatial econometric analysis and instrumental regressions, we find that road and railway construction has a significant negative effect on the urban-rural price divide, suggesting that infrastructure development facilitates market integration between urban and rural areas in China. [ABSTRACT FROM AUTHOR]

With the rapid development of urban rail transit networks, constructing shield tunnels often requires passing underneath existing buildings, which can potentially impact their safety. This study examined the impact of constructing a double-line shield tunnel underneath a railway bridge on the adjacent pile foundation via numerical simulation. Protective measures, including construction parameter control, grouting methods, monitoring, and early warning systems, were implemented to mitigate impacts. The results indicated that the bridge deformation fell within acceptable limits, with maximum horizontal and longitudinal displacements of 0.06 mm and a maximum vertical displacement of −0.31 mm. The railway bridge pile foundation experienced maximum horizontal and longitudinal displacements of 0.47 mm and vertical displacements of −0.23 mm during construction. Enhanced construction quality control and monitoring effectively controlled deformation to ensure the railway safety. This study provides valuable guidance for similar projects and future urban rail transit developments. [ABSTRACT FROM AUTHOR]

Himachal Pradesh, a northern state in India, is located in seismic zones IV and V and is affected by several moderate to strong earthquakes. Given the region's susceptibility to seismic activity, it is always necessary to design structures according to the safety standards available in the country. Shear wave velocity (Vs) averaged up to a depth of 30 m is a crucial factor in designing earthquake-resistant structures in seismically active areas. The current study conducted comprehensive seismic exploration to determine in-situ Vs using active and passive methods at various locations covering the ongoing Bhanupalli–Bilaspur–Beri railway project. This facilitated earthquake hazard assessment and Vs30 calculations. In this work, to estimate a one-dimensional Vs profile, we utilised the joint fit of the horizontal-to-vertical spectral ratio (H/V) technique, a passive approach that utilises ambient noise data and an active seismic technique known as multichannel analysis of surface wave (MASW). This joint fit has provided a 1-D velocity structure. The method employed has demonstrated a consistent correspondence with bore log data and notably, there is a strong correlation between variations in Vs and lithology that is dependent on depth. It has been seen that wave velocity tends to rise with depth within similar formations. For quantifying this relationship, several regression models have been formulated and then validated using different sites, which are excluded in the formulation of the regression relation. We derived shear wave profiles for various stations using lithologs and compared them to existing shear wave profiles and we found a strong agreement between these two datasets. [ABSTRACT FROM AUTHOR]