Search Results (49)

This study investigates how the expansion of Warsaw’s metro system—specifically the opening of the second underground line (M2)—affects urban vibrancy, defined as the diversity and intensity of social, economic, and cultural activities. Using a spatial panel Difference-in-Differences (DiD) model with two-way fixed effects, the analysis examines changes in local vibrancy, proxied by the density of small catering businesses (SCB), across four years (2019–2023). Our results show that while built environment features such as building footprint, parking area, and street furniture positively correlate with vibrancy, the short-term effect of new metro stations is negative: areas within a 15 min walking distance of new stations experienced a relative decline in local activity compared to control areas. This pattern likely reflects a behavioral shift, as residents and consumers increasingly use the metro to access amenities in central, already vibrant districts. However, the effect attenuates over time, suggesting that neighborhoods gradually adapt to new mobility conditions. The findings highlight that large-scale transport investments may generate temporary disruptions before fostering long-term equilibrium and renewed urban vitality, underscoring the need for adaptive urban policies that mitigate transitional impacts and support local socio-economic resilience. Full article

With advantages in efficiency and sustainability, assembly splicing technology promotes construction industry upgrading. However, research on the seismic response of assembly splicing subway stations (ASS) is particularly scarce. This work studies the asymmetric ASS in soft soil, establishing a refined finite element model with soil–structure interactions. Three seismic records with different frequency characteristics are applied for nonlinear incremental dynamic analysis. Based on the seismic records that produce the most unfavorable seismic response, this research is conducted on the damage distribution characteristics and the mechanical responses. In addition, the influence of the splicing response at different locations on the interlayer displacement and internal forces of structures is systematically studied. The results indicate that when seismic records with low-frequency characteristics are inputted, the ASS structure in soft soil develops into the most unfavorable state. Under strong seismic action, the top joint of the sidewall exhibits significant horizontal sliding and opening, making key areas of weak seismic performance. It also indicates that the interface contact between precast and cast-in-place components is the primary factor that is causing internal force redistribution. This study provides a reference for performance-based seismic design of ASS in soft soil. Full article

In the context of the global growth of the collaborative economy, Airbnb has established itself as one of the most influential players in the transformation of the tourist accommodation market, especially in the reconfiguration of urban tourist accommodation. This article examines empirically and critically how this platform operates in Buenos Aires, the most visited city in Argentina and one of the main tourist hubs in South America. Based on a database of 17,249 active listings, the price formation of accommodations is analyzed using a comparative methodological approach between a general linear model (GLM) and a geographically weighted regression (GWR) model. While the GLM allows for capturing general patterns, the GWR reveals significant territorial differences, offering a detailed reading of the spatial behavior of prices in the city. The results show that variables such as the capacity of the accommodation, its type (full house), the host’s condition, the users’ ratings and the proximity to strategic points such as the subway or Plaza de Mayo have a significant influence on prices. In addition, it is shown that the influence of these variables varies by neighborhood, confirming that the pricing logic in Airbnb is deeply territorialized. This study not only provides novel empirical evidence for a Latin American city that has been little explored in the international literature, but also offers useful tools for hosts, urban planners and public decision makers. Its main contribution lies in showing that prices respond not only to accommodation attributes, but also to broader spatial inequalities, opening the debate on the effects of Airbnb on housing access and urban management in cities with strained real estate markets. By shedding light on these territorial asymmetries, the study offers valuable insights for public policy and urban governance and contributes directly to the achievement of Sustainable Cities and Communities (SDG 11), while also supporting Industry, Innovation and Infrastructure (SDG 9) and Reduced Inequalities (SDG 10), by providing practical knowledge that fosters more equitable and sustainable urban development. Full article

The proliferation of tunnel and subway networks in urban areas has heightened concerns regarding their vulnerability to seismic-induced liquefaction. This phenomenon, wherein saturated sandy soils lose strength and behave like a liquid under seismic waves, poses a catastrophic threat to the structural integrity and stability of underground constructions. While extensive research has been conducted to evaluate liquefaction triggering, most existing approaches rely on single ground motion intensity measures (e.g., PGA, I_A), which often fail to capture the combined effects of amplitude, energy, and duration on liquefaction behavior. In this study, the seismic response of saturated sandy soil from Yinchuan was analyzed using the Dafalias–Manzari constitutive model implemented in the OpenSeesPy platform. The model parameters were carefully calibrated using laboratory triaxial results. A total of ten real earthquake records were applied to evaluate two critical engineering demand parameters (EDPs): surface lateral displacement (SLD) and the maximum thickness of the liquefied layer (MTL). The results show that both SLD and MTL exhibit weak correlations with conventional intensity parameters, suggesting limited predictive value for engineering design. However, by applying Partial Least Squares (PLS) regression to combine multiple intensity measures, the prediction accuracy for SLD was significantly improved, with the correlation coefficient increasing to 0.81. In contrast, MTL remained poorly predicted due to its strong dependence on intrinsic soil characteristics such as permeability and fines content. These findings highlight the importance of integrating both seismic loading features and geotechnical soil properties in performance-based liquefaction hazard evaluation. Full article

As the operational speeds of subway trains in China incrementally increase to 160 km/h, the enclosed nature of tunnel environments poses significant challenges by restricting free airflow. This limitation leads to intense airflow disturbances and turbulence phenomena within tunnels, consequently exacerbating aerodynamic noise issues. This study utilizes compressible Large Eddy Simulation (LES) and acoustic finite element methods to construct a computational model of aerodynamic noise for subway trains within tunnels. It employs this model to compare and analyze the near-field noise characteristics of subway trains traveling at 120 km/h on open tracks versus in infinitely long tunnels. The findings indicate that the distribution of sound pressure levels on the surfaces of trains within tunnels is comparatively uniform, overall being 15 dB higher than those on open tracks. The presence of a high blockage ratio in tunnels intensifies the cavity flow between two air conditioning units, making it the region with the highest sound pressure level. The surface sound pressure spectrum within the tunnel shows greater similarity across different segments, with low-frequency sound pressure levels notably enhanced and high-frequency levels attenuating more rapidly compared to open tracks. It is recommended that in tunnels with high blockage ratios, the positioning of subway train air conditioning should not be too high, overly concentrated, submerged, or without the use of sound-absorbing materials. Such adjustments can effectively reduce the sound pressure levels in these areas, thereby enhancing the acoustic performance of the train within the tunnel. Full article

This study presents an AI-enhanced pedestrian simulation model for subway stations, combining the Social Force Model (SFM) with LiDAR trajectory data from Samseong Station in Seoul. To reflect time-dependent behavioral differences, RMSProp-based optimization is performed separately for the morning peak, leisure hours, and evening peak, yielding time-specific parameter sets. Compared to baseline models with static parameters, the proposed method reduces prediction errors (MSE) by 50.1% to 84.7%. The model integrates adaptive learning rates, mini-batch training, and L2 regularization, enabling robust convergence and generalization across varied pedestrian densities. Its accuracy and modular design support real-world applications such as pre-construction design testing, post-opening monitoring, and capacity planning. The framework also contributes to Sustainable Urban Mobility Plans (SUMPs) by enabling predictive, data-driven evaluation of pedestrian flow dynamics in complex station environments. Full article

Subway construction changes land use patterns, disrupting the balance between traffic supply and demand and influencing residents’ activity and travel behaviors along the route. Previous studies have often overlooked the multiple attributes of the subway and their varying impacts on daily activities. To understand how subway construction affects travel and activity patterns, this study analyzed travel data from two years before and after the opening of the Kunming Subway. Propensity score matching was used to control for socioeconomic changes unrelated to the subway. The findings show the following: (1) The subway’s introduction leads to the development of commercial and civic amenities around its stations, attracting wealthier and more educated residents, which contributes to gentrification. (2) Overall, subway construction extends urban residential and employment areas, increasing residents’ dependence on cars and promoting a more motor-centric lifestyle. As a result, the subway’s ability to reduce car usage is limited. (3) The subway alters the impact of the built environment on travel behavior, with residents closer to the subway experiencing shorter travel distances and reduced activity spaces, while those further away maintain longer travel distances and greater activity areas. Full article

Against the backdrop of rapid rail transit development, this study takes Urumqi Metro Line 1 as a case, using geographic information system (GIS) spatial analysis and space syntax Pearson correlation coefficient methods. Focusing on an 800 m radius around station areas, the research investigates the distribution characteristics of commercial facilities and the impact of metro development on commercial patterns through the quantitative analysis and distribution trends of points of interest (POI) data across different historical periods. The study reveals that following the opening of Urumqi Metro Line 1, commercial facilities have predominantly clustered around stations including Erdaoqiao, Nanmen, Beimen, Nanhu Square, Nanhu Beilu, Daxigou, and Sports Center, with kernel density values surging by 28–39%, indicating significantly enhanced commercial agglomeration. Metro construction has promoted commercial POI quantity growth and commercial sector enrichment. Surrounding commercial areas have developed rapidly after metro construction, with the most significant impacts observed in the catering, shopping, and residential-oriented living commercial sectors. After the construction of the subway, the distribution pattern of commercial facilities presents two kinds of aggregation patterns: one is the original centripetal aggregation layout before construction and further strengthened after construction; the other is the centripetal aggregation layout before construction and further weakened after construction, tending to the site level of face-like aggregation. The clustering characteristics of different business types vary. Factors such as subway accessibility, population density, and living infrastructure all impact the distribution of businesses around the subway. The impact of subway accessibility on commercial facilities varies by station infrastructure and urban area. The findings demonstrate how transit infrastructure development can catalyze sustainable urban form evolution by optimizing spatial resource allocation and fostering transportation–commerce synergy. It provides empirical support for applying the theory of transit-oriented development (TOD) in the urban planning of western developing regions. The research not only fills a research gap concerning the commercial space differentiation law of metro systems in megacities in arid areas but also provides a scientific decision-making basis for optimizing the spatial resource allocation of stations and realizing the synergistic development of transportation and commerce in the node cities along the “Belt and Road”. Full article

The rapid development of urban subway network is prompting higher requirements for daylighting in subway stations. The skylight daylighting space of shallow buried subway stations not only improves the quality of light environment but also brings challenges for the optimization of light and thermal performance, especially in areas with hot summers and cold winters. In this paper, key parameters such as illumination, air temperature, and the black sphere temperature of skylight and artificial lighting areas at stations A and B in Shanghai were tested with a field test system. The results show that the light environment in the skylight areas was significantly improved, but the need for regulation and control of the thermal environment increased. Combined with response surface analysis, 10 sample models for two types of daylighting space (partitioned and open atrium styles) were studied and constructed, including 254 simulated working conditions. The results reveal that design parameters such as the number, aspect ratio, depth of light openings, and skylight angle have significant effects on combined energy consumption. The decentralized double slope roof daylighting space has the best performance in partitioned and open atrium-style public areas, and combined energy consumption can be reduced to 385.14 kWh/m². The optimization strategies proposed in this study can provide a quantitative basis for the skylight design of shallow buried subway stations and an important reference for the design of low-carbon and energy-saving underground spaces. Full article

Air pollution not only affects urban production and residents’ lives but also threatens human health, and the construction of the subway is considered an important measure to improve urban traffic congestion and air quality. To test whether the construction and opening of subways with high operating costs can effectively improve urban air quality, this paper takes the opening of subways as a quasi-natural experiment. Based on panel data from 282 cities in China from 2014 to 2021, the difference-in-differences method is used to estimate the impact of subway openings on urban air pollution. It is found that (1) the subway opening significantly reduces urban air pollution, and this conclusion remains valid after a series of robustness tests. (2) Mechanism analysis indicates that subway openings mostly mitigate urban air pollution through the traffic substitution effect, which is generated through the substitution of private car travel. (3) Heterogeneity analyses show that the abatement effect of subway openings on air pollution is more significant when the city is a non-Yangtze River Economic Belt city, or when the city’s economic level is lower, or when the city is a non-resource-based city. Therefore, this paper puts forward targeted policy recommendations, such as optimising the subway layout, promoting the transit-oriented development mode based on the subway system, and implementing differentiated development strategies, with a view to providing certain references for promoting sustainable urban development. Full article

With the accelerated development of subways in China, elevated subway stations (ESSs) capitalize on natural ventilation and lighting to significantly save energy. Nevertheless, their thermal environments are rarely addressed. This study conducts annual thermal environment measurements, surveys, and thermal comfort analysis on five typical ESS buildings. The results of field measurements demonstrate that the station’s thermal environment is influenced by architectural space forms such as skylight ratio, platform doors, openness, and platform form. The standard effective temperature—predicted thermal sensation (SET*—PTS) equation was developed based on the survey, indicating that passengers’ thermal adaptability surpasses the PTS. In summer, the neutral temperatures for passengers in open and enclosed stations are 28.74 SET* °C and 27.13 SET* °C, correspondingly. In winter, they are 23.43 SET* °C and 21.98 SET* °C. Physiological changes that passengers experience during the transition from entering the metro station to arriving at the platform were measured and quantified, which confirmed differences in thermal adaptation during the shift between hot and cold environments, emphasizing thermal delay and accumulation effects. This study provides important guidance for the construction, renovation, and operation of ESS buildings and the development of related standards. Full article

This paper examines the design of antennas for Hi-pass type turnstiles needed to implement a subway free-pass system targeting transportation-disadvantaged individuals. The subway free-pass system allows individuals who have a free-pass card to approach the turnstile with the card on their person, which opens the gate automatically. This system, like the highway Hi-pass, allows users to pass through the subway gate without needing to scan a ticket. For the system to function, antennas are required at both the entrance and exit gates, with an additional antenna needed for the free-pass card, totaling three antennas. The free-pass card functions as a radio-frequency identification (RFID) tag, while the system uses Bluetooth communication. In this paper, we propose a square patch-type microstrip antenna that can be integrated within the turnstile, performing excellently in the Bluetooth band range of 2.420 to 2.485 GHz. Full article

This study focuses on the safe evacuation strategy and evacuation process in the subway train under the fires. The subway station evacuation mode should be adopted if the power system of a subway train is normal on fire. While, the tunnel evacuation mode should be adopted if the power system of the train fails because of the effects of fire. Under the tunnel evacuation mode, the direction of tunnel smoke should be opposite to that of most passengers, and passengers should be evacuated toward the fresh wind. By using the numerical simulation software Pathfinder and PyroSim, the passenger evacuation time under different conditions is calculated, and the safety of the evacuation process is evaluated. The results show that the evacuation time of the station evacuation mode is obviously shorter than that of the tunnel evacuation mode. With the same conditions, the evacuation time of the tunnel evacuation mode is 2193 s, which is about four times as much as the evacuation time of the station evacuation mode (526 s). The total evacuation time increases with the total number of passengers and the proportion of older people and children. Under an oil pool fire, which is an extreme fire condition, the fire environment inside the train may reach a level threatening the passengers’ safety before the evacuation is complete, even before the door opens; therefore, special attention should be paid to the safety issues in stage from the fire begins to the evacuation complete. Full article

The revitalization and renewal of existing urban space is a primary objective in the redevelopment of high-density transit-oriented development (TOD) areas. In this context, offering incentive zoning bonuses is a critical tool for optimizing urban space. However, in some subway-adjacent plots with high building densities, traditional incentive zoning methods face limitations due to insufficient horizontal space. These areas increasingly rely on multi-ground public spaces to balance density with public services. This study investigates new methods of incentive zoning between commercial areas and public spaces in multi-ground public spaces within subway-adjacent plots, using 33 rail transit complexes in Shanghai, China, as the research subject. The findings are presented in the form of visual guidelines to provide guidance on architectural control, with the goal of enhancing the quality of urban public spaces. In this research, a multiple linear regression model is employed, using GNCS_AR (the ratio of ground non-commercial stay to area), which captures both efficiency and equity in public space quality, as the dependent variable. A model is developed in SPSS, incorporating independent variables such as TCA (total commercial area), POS (public open space area), PIS (public indoor space area), and MGZFs (multi-ground zoned floors). This model provides a framework for developers to manage and control public space in multi-ground settings within rail transit complexes. Research has found that MGZFs alone cannot be included as the independent variable in the model, as their absence leaves the model unable to explain three-dimensional spaces. However, incorporating the ratio of RIOPS (the ratio of indoor to outdoor public space) to MGZFs significantly improves the model’s correlation and explanatory capacity. The resulting model demonstrates that, under different POS and MGZF tiers, the influence of PIS and TCA on public space quality varies. Using a typological approach, the study categorizes these complexes into five tiers based on POS and MGZFs. Within the same tier, changes in PIS and TCA types lead to variations in public space quality. The empirical results are translated into diagrams that link data, forms, and indicators to guide the development of three-dimensional spaces. These diagrams, which can be named visual guidelines, provide practical guidelines for optimizing public spaces in these subway-adjacent plots. Full article

Subway station platforms are vulnerable to flood damage. Thus, an investigation of inundation in subway platforms is required to ensure the safety of citizens against flooding. This study analyzed and validated the inundation characteristics and safety areas in a subway station model using experimental inundation depth measurements and numerical simulations. Then by using the simulation, the effects of increased inflow to water velocity and depth were analyzed, and its impact on human models was found by using risk assessments which included specific force ($M_0$), Flood Hazard Degree (FD), Flood Intensity Factors (FIF), toppling velocity, and sliding velocity. The flood risk assessment analysis results show that assessments using $M_0$ could increase uncertainty by broadening the evaluation of risky areas compared to other indices. Also, the drag force applied to the human models was calculated using the simulations, which provided inundation risk values to people in subway stations. Overall, the risk assessments would provide a criterion for flood situations in subway stations. Full article