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Interlocking Shear Groove (ISG) between base plate and main beam serves as the connection for interaction between the longitudinal slab ballastless track (LSBT) and bridge structure. To study the failure characteristics of ISG under low cyclic loads, a test model with a 1:5 scale ratio of base plate-ISG-main beam with 4 different numbers of shear bars was designed and made. Failure mechanism, failure pattern, hysteresis curve, skeleton curve, and other failure characteristics of the ISG under low cyclic loads were studied. Based on test data multiple regression of ISG, the three-fold theoretical skeleton model and the formula were established. By analyzing the hysteretic characteristics of ISG, the hysteretic rule and stiffness degradation rule of loading and unloading are obtained, and then the restoring force model was established and verified. The results show that the failure pattern of the ISG is divided into three stages: (a) appearance of fine cracks on both sides of the interface between the ISG and main beam; (b) with the increase in loading displacement, the interface between the ISG and main beam underwent shear cracking and developed into through cracks, and the shear bars underwent shear deformation; (c) the ISG cracked and failed under the combined action of bending and shear, the upper component tilted, and the shear bars underwent bending and shear deformation. Increasing the number of shear bars in the ISG effectively increased the bearing capacity and stiffness and improved the ability to resist external loads. This led to an effective reduction in the strength and stiffness degradation rate. With the increase in the number of the shear bars, the energy dissipation ratio and energy dissipation capacity of the ISG increased, the better the seismic performance of the specimens. The established three-fold model theoretical skeleton model and the restoring force model of the ISG are in good agreement with the test data, and the calculation method of the model is simple and clear, which effectively reflects the hysteretic performance of the ISG under low cyclic loads. The research results can provide theoretical basis for seismic damage analysis of the LSBT — bridge system of HSR. [ABSTRACT FROM AUTHOR]

Numerous studies have revealed that high-speed railways (HSRs) can efficiently reduce transportation costs for firms and therefore bring more business capacities to firms in regions with HSR services. This paper aims to adopt the difference-in-difference (DID) and PSM (propensity score matching) DID methods to examine the HSR’s causal effects on business costs. The author finds that business costs are significantly reduced due to the operation of HSR lines. Besides, private firms and firms in the secondary and tertiary sectors would experience more reductions of business costs encouraged by the HSR than state-owned and agricultural firms. The placebo test and parallel trend test have proved the feasibility of this study. Finally, this paper provides policy suggestions that the construction of HSR lines needs to be encouraged in order to promote the higher efficiency of business operations for firms and more-balanced spatial business developments in China.

Using a quasi‐natural experiment, we investigate whether the opening of high‐speed railways affects mutual fund holdings. Applying the difference‐in‐difference method, we find that mutual fund holdings in remote listed companies increase after the introduction of high‐speed railways in their cities. This effect is primarily observed within the optimal interval of the railway. Opening high‐speed railways also facilitates mutual fund visits to remote listed companies, resulting in increased holdings. [ABSTRACT FROM AUTHOR]

Numerous studies have revealed that high-speed railways (HSRs) can efficiently reduce transportation costs for firms and therefore bring more business capacities to firms in regions with HSR services. This paper aims to adopt the difference-in-difference (DID) and PSM (propensity score matching) DID methods to examine the HSR's causal effects on business costs. The author finds that business costs are significantly reduced due to the operation of HSR lines. Besides, private firms and firms in the secondary and tertiary sectors would experience more reductions of business costs encouraged by the HSR than state-owned and agricultural firms. The placebo test and parallel trend test have proved the feasibility of this study. Finally, this paper provides policy suggestions that the construction of HSR lines needs to be encouraged in order to promote the higher efficiency of business operations for firms and more-balanced spatial business developments in China. [ABSTRACT FROM AUTHOR]

The analysis of bridge vibration response under train loads is crucial for the operational safety of railway bridge structures. In this study, a three-dimensional coupled dynamic model of train-track-truss arch bridge is established. Based on the numerical simulation results, the effects of different train axle loads and speeds on the vibration response of the truss arch bridge are analyzed, and the time-history changes of the displacement and stress at critical sections of the bridge are revealed. The results show that: during the train operation, the maximum vertical dynamic stress and maximum vertical displacement are linearly related to the train axle load and speed. The greater the train axle load and speed, the larger the maximum vertical dynamic stress and maximum vertical displacement. The maximum vertical acceleration generated during train operation increases linearly with train speed and exponentially with train axle load. The most unfavorable section occurs at the mid-span of the bridge, where the maximum vertical displacement, maximum vertical dynamic stress, and maximum vertical acceleration are all at their peak. This research has significant implications for engineering safety and operation. [ABSTRACT FROM AUTHOR]

The seismic performance of the CRTS II slab ballastless track lateral block (TLB) for high-speed railways (HSRs) is revealed for the first time. Nine test models of the main beam-TLB are constructed with varying quantities and diameters of interface anchorage steel bars. The model scale is 1:2, and the steel scale is 1:4. The study examines the failure mechanism, failure pattern, hysteretic curve, skeleton curve, energy dissipation capacity, ductility, stiffness degradation, and strength degradation of the TLB under low cyclic load. The influence of the diameter and quantity of interface anchorage steel bars on the seismic performance of the TLB is analyzed. The results indicate that the failure pattern of the TLB under low cyclic load can be divided into three stages: (a) the interface of the TLB and main beam initially exhibits minor cracking, which enlarges during loading and closes during unloading; (b) the interface steel bars repeatedly compress the surrounding concrete of the TLB and main beam, and the cracks continue to expand until they penetrate the entire interface, while the interface steel bars undergo shear deformation; (c) the concrete in the interface area between the TLB and main beam is crushed and spalled, and the interface steel bar experiences bending shear deformation, leading to slippage and inclination of the TLB. Increasing the quantity and diameter of interface anchorage steel bars enhances the energy dissipation capacity and ductility of the TLB, reduces the degradation of its strength and stiffness, and improves its seismic capability. However, when the diameter of interface anchorage steel bars reaches 12 mm and the quantity of steel bars reaches 8, the increase rate in energy dissipation capacity and ductility of the TLB slows down while the deterioration rate of strength and stiffness accelerates. [ABSTRACT FROM AUTHOR]

Rail corrugation poses a significant threat to train running safety in the field of railway engineering. Therefore, this study employs numerical analysis to investigate the evolution and formation mechanism of rail corrugation in high-speed railways (HSR). Firstly, a three-dimensional (3D) vehicle-track coupled dynamics (VTCD) model is established, which considers the longitudinal wheel-rail (WR) coupling relationship more adequately. Then, by integrating the USFD wear model into this 3D VTCD model, a long-term iterative wear model is developed to reproduce the corrugation evolution process. The predicted corrugation exhibits two distinct wavelength components and closely matches the sample obtained from China's HSR, validating the established model in terms of reliability. Furthermore, the formation mechanism of these two wavelength components is investigated by analyzing the harmonic behavior of vehicle-track coupled systems (VTCS) and the evolution law of rail corrugation under different calculation conditions. The findings reveal that the 3rd-order vertical rail local bending mode (RLBM) between two wheelsets of a bogie (TW-B) is the primary factor contributing to the formation of the long-wavelength component of rail corrugation. The discrete supports of the fasteners do not affect the 3rd-order vertical RLBM, which can be stably excited. Moreover, the vertical rail vibration has a substantial coupled effect on the longitudinal WR creep. When the 3rd-order vertical RLBM is excited, the coupled effect and the negative longitudinal WR creepage together evidently promote the formation of the short-wavelength component of rail corrugation. [ABSTRACT FROM AUTHOR]

In order to study the seismic vulnerability of high-speed railway bridges in the nearshore area during their lifetime, based on a long-span prestressed rigid frame bridge of a high-speed railway, considering the pile-soil interaction, the vulnerability of components of the bridge under different seismic directions is calculated by quantifying the damage index and using the increment dynamic analysis (IDA). The second-order boundary method is adopted to establish the full-life seismic vulnerability surface of the bridge system, and the time-varying seismic vulnerability after the durability damage during the service life of the nearshore high-speed railway bridge is studied. The research results show that under the design seismic action of the long-span bridge of high-speed railway, the probability of slight damage to the bridge system in the longitudinal and transverse bridge directions is 46.4% and 15.1%, respectively; the probability of severe damage is small, and reaches 18.7% and 9.7% respectively under the rare earthquake action. The seismic vulnerability of the bridge in the longitudinal direction is greater than that in the transverse direction. When the pile-soil interaction is considered, the system vulnerability increases, but the increase is small. Under the rare seismic action in the longitudinal direction of the bridge, the exceedance probability of severe damage increases by 1.1%. During the whole life cycle of the bridge, when the service life is 100 a, the exceedance probability of slight damage under the design seismic action of the bridge is 17.1% higher than that of the new bridge. The seismic vulnerability of the high-speed railway bridge gradually increases with the increase of the service time. The durability damage in the later stage of the service life is more serious, and the seismic vulnerability increases obviously. However, the complete failure of the high-speed railway bridge does not occur basically throughout the whole life cycle. [ABSTRACT FROM AUTHOR]

The article presents the development of high-speed rail in Japan, an island country located within the Ring of Fire of the Pacific. The analysis of the technical condition and the stages of the historical development of highspeed railways were preceded by an assessment of the economy and transport as well as a study of transport intensity. The summary of the article includes the effects and benefits of using high-speed rail, as well as methods of financing and plans for further development. [ABSTRACT FROM AUTHOR]

In recent years, the safety issues of high-speed railways have remained severe. The intrusion of personnel or obstacles into the perimeter has often occurred in the past, causing derailment or parking, especially in the case of bad weather such as fog, haze, rain, etc. According to previous research, it is difficult for a single sensor to meet the application needs of all scenario, all weather, and all time domains. Due to the complementary advantages of multi-sensor data such as images and point clouds, multi-sensor fusion detection technology for high-speed railway perimeter intrusion is becoming a research hotspot. To the best of our knowledge, there has been no review of research on multi-sensor fusion detection technology for high-speed railway perimeter intrusion. To make up for this deficiency and stimulate future research, this article first analyzes the situation of high-speed railway technical defense measures and summarizes the research status of single sensor detection. Secondly, based on the analysis of typical intrusion scenarios in high-speed railways, we introduce the research status of multi-sensor data fusion detection algorithms and data. Then, we discuss risk assessment of railway safety. Finally, the trends and challenges of multi-sensor fusion detection algorithms in the railway field are discussed. This provides effective theoretical support and technical guidance for high-speed rail perimeter intrusion monitoring. [ABSTRACT FROM AUTHOR]

This study aims to empirically examine the effect of high-speed railways (HSR) on the urban agglomeration of producer services. We analyze China's urban panel data from 2003 to 2019 using a time-varying Difference-in-Differences (DID) model. Our findings indicate that as HSR networks expand across 282 cities, producer service agglomeration decreases significantly, resulting in a more balanced spatial distribution of these services. The analysis of heterogeneity indicates that low-level producer services have a greater impact than their advanced counterparts, particularly in the central and eastern regions. Our research highlights the significance of coordinating industry specialization, city levels, and regional dynamics in China's future producer services development. The evidence indicates that the introduction of HSR systems contributes to the harmonization of the distribution of producer services to the advantage of both central and peripheral cities. Moreover, our findings highlight the potential for high-speed railways to promote sustained and robust economic growth by facilitating efficient factor flow. The study integrates knowledge economy perspectives with transportation advancements in this context, underscoring the intricate relationship between urbanization, economic dynamics, and knowledge-driven development. [ABSTRACT FROM AUTHOR]

The improvement of transportation infrastructure can reshape the economic geogra‐ phy patterns. The opening of high-speed railways promotes the flow of innovation elements among regions, enhances the knowledge spillover effect, affects regional innovation activities, or even affects the structure of regional knowledge innovation network. Based on the extant literature, this article summarized the relationship between high-speed railways and knowledge innovation in cities along railway lines in terms of the exact impact, differential performance and the mechanism, and further explained the micro mechanism of the impact of the opening of high-speed railways on regional knowledge innovation from the perspective of enterprises. According to the literature analysis, this article draws the following conclusions. Firstly, high-speed rail‐ ways do have an impact on knowledge innovation, but there are regional differences, which are related to geographical distance and urban heterogeneity. Secondly, the opening of high-speed railways promotes the flow and agglomeration of innovation factors, and expands knowledge spillover effects, which will affect regional knowledge innovation. However, both the agglomeration effect and knowledge spillover effect have two sides, so they show different influence effects in different regions. Thirdly, the opening of high-speed railways is conducive to expanding the commuting field, broadening knowledge channels and increasing temporary agglomeration, so as to increase the opportunities for enterprises to obtain innovative talents, cross-regional co‐ operation and knowledge sharing, and promote their innovative output. Finally, this article puts forward an analytical framework and some topics worthy of in-depth discussion. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Europejski is the property of University of Warsaw 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.)

Pile-supported embankments are typically composed of soil-rock mixtures. within these structures, while the soil arching effect is crucial for effective load transfer, it remains incompletely understood, particularly when the impact of various loading conditions needs to be considered. This study investigates this problem using a 1 g physical experimental modeling approach. Subsequently, a DEM model for a full-scale pile-supported embankment of high-speed railways, accounting for multiple pile interactions, is established with proper model calibration. Numerical simulations are conducted to explore the load transfer mechanism and soil arching processes under self-weight, embankment preloading, and train-induced dynamics influences. The findings indicate that under self-weight, fully developed soil arching structures can be achieved with a sufficiently high embankment height, although they can diminish as the soil-pile relative displacement increases. However, during embankment preloading processes, represented by static loading, pressure can be transferred from pile caps to subsoil regions, potentially compromising the integrity of soil arching structures. Train-induced dynamics effects are modeled as cyclic loading inputs, revealing that an increase in loading frequency leads to weakened dynamic pressure fluctuation for both pile caps and subsoil regions, with a limited impact on the valley values of the pressures. Additionally, a higher loading frequency corresponds to smaller accumulated loading plate settlements. [ABSTRACT FROM AUTHOR]

The analysis of bridge vibration response under train loads is crucial for the operational safety of railway bridge structures. In this study, a three-dimensional coupled dynamic model of train-track-truss arch bridge is established. Based on the numerical simulation results, the effects of different train axle loads and speeds on the vibration response of the truss arch bridge are analyzed, and the time-history changes of the displacement and stress at critical sections of the bridge are revealed. The results show that: during the train operation, the maximum vertical dynamic stress and maximum vertical displacement are linearly related to the train axle load and speed. The greater the train axle load and speed, the larger the maximum vertical dynamic stress and maximum vertical displacement. The maximum vertical acceleration generated during train operation increases linearly with train speed and exponentially with train axle load. The most unfavorable section occurs at the mid-span of the bridge, where the maximum vertical displacement, maximum vertical dynamic stress, and maximum vertical acceleration are all at their peak. This research has significant implications for engineering safety and operation.

High-speed railway bridges are subjected to normative limitations concerning maximum permissible deck accelerations. For the design of these structures, the European norm EN 1991-2 introduces the high-speed load model (HSLM)—a set of point loads intended to include the effects of existing high-speed trains. Yet, the evolution of current trains and the recent development of new load models motivate a discussion regarding the limits of validity of the HSLM. For this study, a large number of randomly generated load models of articulated, conventional, and regular trains are tested and compared with the envelope of HSLM effects. For each type of train, two sets of 100,000 load models are considered: one abiding by the limits of the EN 1991-2 and another considering wider limits. This comparison is achieved using both a bridge-independent metric (train signatures) and dynamic analyses on a case study bridge (the Canelas bridge of the Portuguese Railway Network). For the latter, a methodology to decrease the computational cost of moving loads analysis is introduced. Results show that some theoretical load models constructed within the stipulated limits of the norm can lead to effects not covered by the HSLM. This is especially noted in conventional trains, where there is a relation with larger distances between centres of adjacent vehicle bogies. [ABSTRACT FROM AUTHOR]

Abstract High-speed railway bridges are subjected to normative limitations concerning maximum permissible deck accelerations. For the design of these structures, the European norm EN 1991-2 introduces the high-speed load model (HSLM)—a set of point loads intended to include the effects of existing high-speed trains. Yet, the evolution of current trains and the recent development of new load models motivate a discussion regarding the limits of validity of the HSLM. For this study, a large number of randomly generated load models of articulated, conventional, and regular trains are tested and compared with the envelope of HSLM effects. For each type of train, two sets of 100,000 load models are considered: one abiding by the limits of the EN 1991-2 and another considering wider limits. This comparison is achieved using both a bridge-independent metric (train signatures) and dynamic analyses on a case study bridge (the Canelas bridge of the Portuguese Railway Network). For the latter, a methodology to decrease the computational cost of moving loads analysis is introduced. Results show that some theoretical load models constructed within the stipulated limits of the norm can lead to effects not covered by the HSLM. This is especially noted in conventional trains, where there is a relation with larger distances between centres of adjacent vehicle bogies.

Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks, provide safe and smooth rides, and reduce the maintenance frequency. In this paper, the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus. It is then compared to the performance of a ballasted track. First, slab and ballasted track models are developed to replicate the full-scale testing of track sections. Once the models are calibrated with the experimental results, the novel slab model is developed and compared against the calibrated slab track results. The slab and ballasted track models are then extended to create linear dynamic models, considering the track geodynamics, and simulating train passages at various speeds, for which the Ledsgård documented case was used to validate the models. Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil, considering the issues associated with critical speeds. Various train loading methods are discussed, and the most practical approach is retained and described. Moreover, correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards. It is found that considering the same ground condition, the slab track deflections are considerably smaller than those of the ballasted track at high speeds, while they show similar behaviour at low speeds. [ABSTRACT FROM AUTHOR]

Featured Application: The findings of this study can be applied in engineering practice for the protection of buried pipelines and other underground life lines crossing under or near continuously expanding high-speed railway lines. High-speed railway (HSR) lines commonly operate over hundreds of kilometers, crossing several other large-scale infrastructures, such as highways, tunnels, bridges, and pipelines. This fact makes adjacent infrastructure more vulnerable to high-speed train (HST)-induced vibrations; thus, their potential distress should be carefully examined. The current study aims to assess the level of traffic-induced vibrations on the surface of buried pipelines vertically crossing under an HSR line. Firstly, the necessity to reduce high vibration levels is highlighted, utilizing a three-dimensional (3D) finite element model in conjunction with the moving load approach. Subsequently, an efficient mitigation measure is proposed to minimize these vibrations. For this purpose, a low-weight, high-performance geosynthetic fill material, i.e., expanded polystyrene (EPS) geofoam blocks, has been implemented between the HSR line and the buried pipeline to minimize the impact of vibrations. In this manner, HST-induced vibrations are reflected on EPS blocks, preventing them from reaching the pipeline surface. Based on this detailed parametric study, useful conclusions are drawn regarding the mechanical properties and geometry of the EPS protection layer. [ABSTRACT FROM AUTHOR]

Abstract Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks, provide safe and smooth rides, and reduce the maintenance frequency. In this paper, the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in Abaqus. It is then compared to the performance of a ballasted track. First, slab and ballasted track models are developed to replicate the full-scale testing of track sections. Once the models are calibrated with the experimental results, the novel slab model is developed and compared against the calibrated slab track results. The slab and ballasted track models are then extended to create linear dynamic models, considering the track geodynamics, and simulating train passages at various speeds, for which the Ledsgård documented case was used to validate the models. Trains travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil, considering the issues associated with critical speeds. Various train loading methods are discussed, and the most practical approach is retained and described. Moreover, correlations are made between the geotechnical parameters of modern high-speed rail and conventional standards. It is found that considering the same ground condition, the slab track deflections are considerably smaller than those of the ballasted track at high speeds, while they show similar behaviour at low speeds.

An efficient model of high-speed railway simply supported bridge with China Railway Track Structure II (CRTS II) ballastless track structure, setup on ANSYS platform, is proposed in this article. The goal is to improve the low computational efficiency and reduce the high computer memory consumption caused by complex bridge models of numerous spans. Programming language and modeling procedures are utilized to ensure that all spans in the proposed model of a large multispan simply supported railway bridge have consistent boundary conditions. Hence, only the middle span is simulated. The comparison of the first longitudinal vibration modes and first natural frequencies of the proposed model and the conventional simply supported bridge model preliminarily validates the feasibility of the model. It also confirms the range of the span number that the proposed model can simulate with accuracy. Taking into account eight different seismic excitations, the results further prove that the proposed model can significantly improve the computational efficiency of the seismic analyses, and can decrease the modeling complexity and calculation time cost without loss of accuracy. The design verification of three different heights of pier groups and the consideration of nonlinear springs enables the proposed model to be utilized in a wide range of applications. As a conclusion, for seismic simulation of high-speed railway simply supported bridges, the proposed model is a reliable alternative for practical engineering simulation. [ABSTRACT FROM AUTHOR]

With the rapid developments of fifth generation (5G) mobile communication networks in recent years, different use cases can now significantly benefit from 5G networks. One such example is high-speed trains found in several countries across the world. Due to the dense deployment of 5G millimetre wave (mmWave) base stations (BSs) and the high speed of moving trains, frequent handovers (HOs) occur which adversely affect the Quality-of-Service (QoS) of mobile users. User association for load balancing is also a key issue in 5G networks. Therefore, HO optimisation and resource allocation are major challenges in the mobility management of high-speed train systems. Handover Margin (HOM) and Time-to-Trigger (TTT) parameters are crucial for the HO process since they affect the key performance indicators (KPIs) of high-speed train systems in 5G networks. To manage system performance from the aspect of predictive analytics, we have modelled system performance of mobility management through machine learning (ML). First, the HO management process of a high-speed train scenario is framed as a supervised ML problem. The inputs for the problem are regression task, HOM and TTT and the outputs are key performance indicators (KPIs). Second, data processing is accomplished after generating a simulation dataset. Several methods are employed for the dataset, such as Adaptive Boosting (AdaBoost), Gradient Boosting Regression (GBR), CatBoost Regression (CBR), Support Vector Regression (SVR), Multi-layer Perceptron (MLP), Kernel Ridge Regression (KRR) and K-Nearest Neighbour Regression (KNNR). Tenfold cross validation is then applied for choosing the best hyperparameters. Finally, the deployed methods are compared in terms of the Mean Absolute Error (MAE), Mean Square Error (MSE), Maximum Error (Max E), and R2 score metrics. From the MAE results, CBR achieves the best outcomes for load level and throughput KPIs with 0.003 and 0.0144, respectively. On the other hand, GBR achieves the best results for call dropping ratio (CDR), radio link failure (RLF) and spectral efficiency KPIs with 0.354, 0.082 and 0.354, respectively. CBR also follows GBR for the three KPIs with 0.356, 0.082 and 0.357, respectively. Only a slight difference in estimations is present. MLP achieves the best results for HO ping-pong (HOPP) and HO probability (HOP) KPIs with 0.0045 and 0.011, respectively. This is followed by GBR and CBR. From the MSE outcomes, CBR and GBR exhibit the best results for load level and throughput KPIs with 2e-5 and 3e-5, respectively. GBR attains the best results for CDR, RLF and spectral efficiency KPIs with 0.25, 0.011 and 0.025, respectively. Accordingly, CBR follows GBR with slightly different errors for the three KPI estimations. MLP achieves the best results for HOPP and HOP KPIs with 5e-5 and 3.6e-5, respectively. Again, this is followed by GBR and CBR for the estimation of these results. This indicates that CBR and GBR can capture relationships between inputs and KPIs for the dataset used in this study, outperforming all other methods generally used for solving this problem.

High carbon emission efficiency is an important guarantee for achieving the goals of "carbon peaking" by 2030 and "carbon neutrality" by 2060. Based on the panel data of prefecture-level cities from 2003 to 2018, the spatial difference-in-difference model is used to empirically test the spatial spillover effect of the opening of high-speed rail (HSR) on urban total factor carbon emission efficiency (TFCEE). The results show that the spatial correlation of TFCEE between regions is positive, and the opening of HSR has a significant positive spatial spillover effect on TFCEE. The conclusion is still valid after a series of robustness tests. We further employ a mediating effects model to verify that green technology innovation and labour resource mismatch are two important channels of influence for the opening of HSR to improve TFCEE. The heterogeneity analysis shows that the opening of HSR significantly promotes the higher development level and the provincial capital TFCEE. [ABSTRACT FROM AUTHOR]

The construction of high-speed railways and the smart city pilot (HSR-SCP) demonstrates the synergy of traditional and new infrastructure upgrades, which has a significant influence on the economic transition and green economic growth. However, little study has been conducted on the impact of HSR-SCP synergy on carbon emissions. Applying China's prefecture-level panel data, this paper, therefore, attempts to investigate the effect of HSR-SCP on carbon emissions and uncover its in-depth mechanism through the multi-period difference-in-differences model. Notably, an appropriate instrumental variable for HSR-SCP is introduced to address possible endogeneity. The main conclusions indicate that the construction of HSR-SCP plays an essential role in cutting carbon emissions, which is still valid after adopting the instrumental variable method and some robustness tests. Furthermore, green technology innovation plays a crucial intermediary role in that relationship. Finally, the carbon reduction effect of HSR-SCP is significant in Mid-Eastern China and cities with high population sizes and administrative levels, but not in other cities or regions. The research conclusions demonstrate the significant synergy of traditional and new infrastructure upgrades on carbon reduction and provide an empirical foundation for developing countries to realize low-carbon development through optimizing smart infrastructure and promoting green technology innovation. [ABSTRACT FROM AUTHOR]

We investigate the impact of the construction of large-scale high-speed railways (HSRs) on regional multidimensional poverty in China. We find that the opening of HSRs can reduce this poverty indicator. This association is robust to a series of checks. Regarding the mechanisms, the opening of HSRs can improve regional accessibility, enhance local tourism, increase labor mobility and promote human capital accumulation, which alleviates multidimensional poverty. Further research indicates the regional heterogeneity of the effect. This research supplements poverty alleviation theory from the perspective of public infrastructure and offers insight into how multidimensional poverty arises and how it can be alleviated. [ABSTRACT FROM AUTHOR]

With the rapid developments of fifth generation (5G) mobile communication networks in recent years, different use cases can now significantly benefit from 5G networks. One such example is high-speed trains found in several countries across the world. Due to the dense deployment of 5G millimetre wave (mmWave) base stations (BSs) and the high speed of moving trains, frequent handovers (HOs) occur which adversely affect the Quality-of-Service (QoS) of mobile users. User association for load balancing is also a key issue in 5G networks. Therefore, HO optimisation and resource allocation are major challenges in the mobility management of high-speed train systems. Handover Margin (HOM) and Time-to-Trigger (TTT) parameters are crucial for the HO process since they affect the key performance indicators (KPIs) of high-speed train systems in 5G networks. To manage system performance from the aspect of predictive analytics, we have modelled system performance of mobility management through machine learning (ML). First, the HO management process of a high-speed train scenario is framed as a supervised ML problem. The inputs for the problem are regression task, HOM and TTT and the outputs are key performance indicators (KPIs). Second, data processing is accomplished after generating a simulation dataset. Several methods are employed for the dataset, such as Adaptive Boosting (AdaBoost), Gradient Boosting Regression (GBR), CatBoost Regression (CBR), Support Vector Regression (SVR), Multi-layer Perceptron (MLP), Kernel Ridge Regression (KRR) and K-Nearest Neighbour Regression (KNNR). Tenfold cross validation is then applied for choosing the best hyperparameters. Finally, the deployed methods are compared in terms of the Mean Absolute Error (MAE), Mean Square Error (MSE), Maximum Error (Max E), and R2 score metrics. From the MAE results, CBR achieves the best outcomes for load level and throughput KPIs with 0.003 and 0.0144, respectively. On the other hand, GBR achieves the best results for call dropping ratio (CDR), radio link failure (RLF) and spectral efficiency KPIs with 0.354, 0.082 and 0.354, respectively. CBR also follows GBR for the three KPIs with 0.356, 0.082 and 0.357, respectively. Only a slight difference in estimations is present. MLP achieves the best results for HO ping-pong (HOPP) and HO probability (HOP) KPIs with 0.0045 and 0.011, respectively. This is followed by GBR and CBR. From the MSE outcomes, CBR and GBR exhibit the best results for load level and throughput KPIs with 2e-5 and 3e-5, respectively. GBR attains the best results for CDR, RLF and spectral efficiency KPIs with 0.25, 0.011 and 0.025, respectively. Accordingly, CBR follows GBR with slightly different errors for the three KPI estimations. MLP achieves the best results for HOPP and HOP KPIs with 5e-5 and 3.6e-5, respectively. Again, this is followed by GBR and CBR for the estimation of these results. This indicates that CBR and GBR can capture relationships between inputs and KPIs for the dataset used in this study, outperforming all other methods generally used for solving this problem. [ABSTRACT FROM AUTHOR]

High-speed railway (HSR) lines commonly operate over hundreds of kilometers, crossing several other large-scale infrastructures, such as highways, tunnels, bridges, and pipelines. This fact makes adjacent infrastructure more vulnerable to high-speed train (HST)-induced vibrations; thus, their potential distress should be carefully examined. The current study aims to assess the level of traffic-induced vibrations on the surface of buried pipelines vertically crossing under an HSR line. Firstly, the necessity to reduce high vibration levels is highlighted, utilizing a three-dimensional (3D) finite element model in conjunction with the moving load approach. Subsequently, an efficient mitigation measure is proposed to minimize these vibrations. For this purpose, a low-weight, high-performance geosynthetic fill material, i.e., expanded polystyrene (EPS) geofoam blocks, has been implemented between the HSR line and the buried pipeline to minimize the impact of vibrations. In this manner, HST-induced vibrations are reflected on EPS blocks, preventing them from reaching the pipeline surface. Based on this detailed parametric study, useful conclusions are drawn regarding the mechanical properties and geometry of the EPS protection layer.

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Nowadays, riding comfort is more significant than before for evaluating the quality of high–speed railways and sitting is the most common posture for its passengers. This study aimed to analyze and optimize the pressure distribution and sitting comfort of second–class seats with different design parameters. Firstly, 21 pressure features were calculated after the field sitting tests conducted on a CRH Train. The subjective comfort was quantified as a linear combination of 6 pressure features in 21, which were selected using stepwise regression analysis (R2 = 0.684). A seat-human finite element model was established using THUMS for a human body and MAT_57 for the seat foam. Finally, this study analyzed the effects of foam and seat angles on interface pressure distribution and comfort ratings. The set of design parameters with the highest comfort was selected from 12 free combinations. The results show that the seat foam with less stiffness may not improve sitting comfort due to the asymmetry of the seat frame. Moreover, appropriately increasing the stiffness of the cushion and backrest will not lead to a decrease in subjective feelings and the pressure distribution becomes more reasonable as the inclination angle increases within 10 degrees. The final optimization increases the computational comfort of the seat-human model by 6.5 in a −50 to 50 scale. [ABSTRACT FROM AUTHOR]

The development of materials engineering has facilitated the design of slender, light bridges replacing standard construction materials with others, which fulfil their purpose both in terms of structural behaviour and safety. This article focuses on the presentation of the problems related to the modelling of bridges and their loads modelling train passages, as well as an analysis of the influence of load parameters on the dynamic response of a structure. The problem has become essential with the development of materials engineering which enabled the design of slender and light bridges according to the assumptions of sustainable development. The article contains a number of numerical analyses which allowed the verification of the developed finite element bridge model (frame and plate-frame types) in terms of the possibility of using them at the design stage. The load was modelled as a system of concentrated forces, the so-called moving load (ML) model. The results obtained from theoretical analyses were compared with in situ measurements of the existing bridge subjected to the load variable in time (set of locomotives ST43 and ST45 and locomotive EP09). It has been found that in dynamic analysis, modelling of the load is essential. A simplified load model such as ML can be used when displacement values are the only results analysed in detail. ML and finite element plate and frame models give high accordance of the displacement results.

The high-quality development of enterprises is the micro-foundation of China's economic growth model from "speed and scale" to "quality and efficiency," in which China's transportation infrastructure, especially the high-speed railways (HSRs), plays an indispensable role. We select the propensity score matching and difference in difference (PSM-DID) model as the identification strategy and empirically analyze the impact of the HSR on the high-quality development of enterprises based on empirical data of 1331 A-share listed companies in China. The results show that the HSR has a significant positive impact on the high-quality development of enterprises. This effect is more substantial for enterprises in the Pearl River Delta, the Triangle of Central China, and small and medium-sized cities. The HSR inhibited the high-quality development of enterprises in the mining, culture, sports, and entertainment industries in eastern and central China. The reason is the restriction of the ability to create social and environmental value and the influence of monopolistic competition. The HSR improves labor mobility, capital expansion, and knowledge spillovers, thereby promoting the high-quality development of enterprises. However, new infrastructure mainly improves the high-quality development of enterprises by promoting knowledge spillovers and technological innovation. This paper contributes to the modernization of China's HSR network and provides essential insights for the HSR to achieve sustainable development goals. [ABSTRACT FROM AUTHOR]