Metro Station Research Articles

On the Construction of Admissible Orders for Tuples and Its Application to Imprecise Risk Matrices

The imprecision inherent in human opinions is not properly modeled by crisp numbers. Other more complex structures like intervals or tuples capture better the imprecision of human assessments. This makes them very useful in decision problems. However, they cannot be easily compared. Despite they grasp better decision-makers inaccuracy, the lack of a natural total order for such structures makes the determination of the best alternative a difficult task. In this contribution, we explore how to obtain new total orders for (ordered) tuples paying special attention to admissible orders (total orders that extend the lattice order). The resulting orders are applied to four-dimensional ordered tuples that represent risk assessments in an imprecise environment. In addition, two case studies involving risk matrices in educational transport and the construction of a metro station are also provided.

Causal mediation analysis of social and environmental factors in pathways from a metro intervention to eudaimonic wellbeing among older people

BackgroundThis research aims to unravel the pathways linking transport with eudaimonic wellbeing among older people, considering the mediating role of social and environmental factors. MethodsWe focused on outcomes across six dimensions of eudaimonic wellbeing: self-acceptance, autonomy, positive relations with others, environmental mastery, purpose in life, and personal growth. Using a new metro line as a natural experiment, we collected cohort data of 449 older adults before and after the opening of a new metro line. The treatment group consisted of participants living within the 400-m buffer zones surrounding the new metro stations, while the control group consisted of those living in comparable station catchments. The mediators include social engagement and environmental perception. We first used difference-in-difference (DID) models to estimate the metro's direct influence on these eudaimonic elements. Causal mediation analyses were then conducted to delved into how the social and environmental factors mediated these effects. ResultThe new metro enhanced the treatment group's environmental mastery, life purpose, and self-acceptance (p < 0.05). These improvements were partly attributed to promoted social engagement and improved environmental perceptions triggered by the metro development (p < 0.05). Notably, the environmental perceptions demonstrated a stronger mediating effect than the social factors. Discussion and conclusionTransport interventions could effectively counteract the age-related eudaimonic decline. The enhancement of environmental perceptions played a key role in the effectiveness of the metro intervention. Our findings contribute to the understanding of casual mechanisms of transport and wellbeing which is vital for developing transport policies and projects that address the needs of an ageing population.

Coupling characteristics of construction safety risk and complicated factors of metro station: a case study of Ningbo

ABSTRACT This paper investigates the coupling relationship and degree of complex factors corresponding to the metro station construction in the Ningbo region. To this end, the interpretative structural modeling (ISM) method, a structural interpretation model, is utilized to develop the coupling connection network of construction risk factors. Moreover, the cloud model theory and coupling degree model are used to calculate the risk factor coupling degree within and between the construction safety risk subsystems. The analysis indicates that the coupling degree of risk factors within and among subsystems is notably high, falling into categories characterized by high coupling and strong coupling. It is also found that the entire coupling system is in a state of high-strength coupling. Therefore, during the construction process, the coupling impact of risk factors must be avoided, and risk factors must be prevented from further developing into risk events. The quantitative evaluation of the coupling degree between and among risk factor subsystems in this study provides a reference for project risk evaluation and facilitates the development of subsequent construction safety measures.

Research on the Optimal Design of Retaining Piles of a Wide Metro Tunnel Foundation Pit Based on Deformation Control

Engineers pay more and more attention to the economic benefits of foundation pit engineering. At present, the optimal design of the foundation pit supporting structure mainly focuses on strength and functional design, and there is no mature theoretical design method for deformation control. In this paper, a method for calculating the overall deformation of a foundation pit supporting structure based on the principle of minimum potential energy is proposed. Based on this method, the optimal design of the foundation pit of Guangzhou Baiyun District Comprehensive Transportation Hub Metro Station is realized. The deformation calculation results and optimization design scheme are validated by finite element numerical simulation and field monitoring data. The results show that the proposed theoretical algorithm predicts the pile deformation curves better than the finite element method, suggesting the proposed theoretical method is reasonable and the optimization scheme of the retaining pile is feasible. In the optimized design, the deformation of the foundation pit retaining pile is controlled by its push-back effect. The proposed deformation calculation method can realize the overall deformation calculation of the foundation pit supporting structure.

Faster, taller, better: Transit improvements and land use policies

We study the interaction between transit improvements and land use policies. Bengaluru, one of India’s largest cities, inaugurated a metro system in 2011 but has extremely low building heights, even near metro stations. We build a rich dataset and a quantitative spatial model in which heterogeneous workers choose among different commuting modes. We find that the metro increases citywide output and welfare, even net of costs. However, the net gains are several times larger with transit-oriented development (TOD), i.e., when height limits are relaxed near stations. Moreover, TOD and the construction of the metro are complementary policies.

Exploring the service needs and the common-suited strengthening paths for bicycle-sharing services based on the AIA-NRM technique in consideration of various users

ABSTRACT Near metro stations in urban areas, a public bicycle rental service allows users to rent bicycles for leisure, short-distance connections, and daily commuting. This study aims to explore the driving factors of bicycle-sharing service systems (BSSSs) and different users’ preferences and service needs (leisure & recreation users, short-connection users, and daily commuting users). The four driving forces (primary services, primary facilities, ancillary services, and ancillary facilities) are applied to evaluate the BSSSs. The researcher used the attention and importance analysis (AIA) technique to assess service driving factors’ attention and importance status in the bicycle-sharing service systems (BSSSs). The DEMATEL technique was also employed to establish a network relation map (NRM) approach for different users. The researcher also combines the AIA and NRM techniques to provide the AIA-NRM technique for identifying common applicable paths and enhancement strategies for the BSSS. Furthermore, this study analyzes various institutions and BSSS service providers from multiple users’ perspectives, determines the development direction of BSSSs, evaluates related challenges, and finds sustainable strategies for strengthening BSSSs.

Does yesterday’s accessibility shape today’s TOD-nesses in metro station areas? A tale of Shenzhen, China

As an overarching policy and development model, transit-oriented development (TOD) is widely used to promote the integration of land use and transit services, which arguably brings about many benefits. TOD advocates have continuously paid much attention to metro station areas (MSAs), i.e., areas within a reasonable walking distance to a metro station. To TOD advocates, well-planned MSAs should have a sufficient supply of TOD-nesses encapsulating characteristics such as destinations, density, diversity, and design. In the existing scholarship, however, little has been done on (a) TOD-nesses’ potential “consumers,” the population that is only a short metro ride away from an MSA, i.e., the metro-based accessibility (MBA) to the consumers of the MSA; and (b) whether and how TOD-nesses of one MSA and several MSAs in proximity are affected by the MBA. With the help of big and/or open data, we examine whether and to what degree the MBA of an MSA cluster (MSAC), a set of MSAs within t minutes of a metro ride from a metro station is correlated to that MSAC’s TOD-nesses in Shenzhen, China. We measure the MBA by the daytime/nighttime population in the same MSAC. We quantify TOD-nesses using the published indices or the averages of the indices in a refereed article. Coefficient of geography association, Gini index, pairwise correlation, and linear regression analyses are carried out. We find that the MBA in one period significantly predicts MSAC-level TOD-nesses in ensuing periods. However, the MBA’s prediction power decreases or even disappears over time. Besides, metro station characteristics such as the jurisdiction membership significantly predict the overall TOD-nesses and individual aspects of the TOD-nesses after controlling for the MBA. Our study thus sheds new light on meso- or MSAC-level TOD-nesses and related policy and planning evaluation.

Revealing the evolution of spatiotemporal patterns of urban expansion using mathematical modelling and emerging hotspot analysis

The rapid expansion of cities in developing countries has led to many environmental problems, and the mechanism of urban expansion (UE), as a more complex human-land coupled system, has always been a difficult issue to research. This paper introduces a new approach by establishing an analytical framework for spatiotemporal pattern mining, exemplified by studying the urban growth of Changsha City from 1990 to 2019. Initially, an emerging hotspot analysis model (EHA) is employed to examine the spatiotemporal changes of urban growth on a macro scale. Mathematical models are subsequently utilized to quantify the correlations between urban expansion and selected infrastructural and topographical factors. Building on these findings, the paper constructs mathematical models to further quantify the spatiotemporal evolution of various urban sprawl patterns across different regions, aiming to elucidate and quantify the significant variations in UE over time and space. The study reveals that, as an emerging city, Changsha's hotspots of urban expansion prior to 2003 were primarily concentrated in the city centre, subsequently spreading to the periphery. The radial influence of metro stations on UE is notably less than that of railway stations—approximately 3 km versus 8 km—and the impact diminishes rapidly before gradually tapering off. Moreover, UE in Changsha predominantly occurs on slopes with gradients ranging from 1.1° to 7.5°, and significant development capacity is observed at elevations between 36.1 m and 78.3 m above sea level, with a tendency for urban sprawl to migrate to lower elevations. The paper also identifies three distinct patterns of urban expansion across different regions: an initial slow-growth phase, followed by a rapid escalation to a peak, and subsequently a swift decline to near stagnation. Additionally, it highlights a significant correlation between the proportion of built-up areas at the micro-regional scale and the stages of UE. This correlation was quantitatively analysed by constructing a logistic function, which demonstrated a robust fit that effectively captures spatiotemporal heterogeneity in the dynamics of UE. These insights enhance the selection of drivers in urban simulation models and deepen the understanding of the complex dynamics that influence urban development.

Comparison of the Workday and Non-Workday Carbon Emission Reduction Benefits of Bikeshare as a Feeder Mode of Metro Stations

Bikeshare, as a convenient transport mode, can address the first- and last-mile travel needs of metro trips while generating many environmental benefits, such as reducing the use of environmentally unfriendly transport modes and lowering the carbon emissions of the urban transportation system. This paper takes bikeshare as a feeder mode of metro stations (BS-FMMS) as the research object and compares the spatial and temporal differences in the carbon emission reduction benefits of BS-FMMS on workdays and non-workdays by using the framework of BS-FMMS carbon reduction benefit analysis and the methods of time-series analysis, spatial aggregation analysis, and box plot analysis. The results show that the carbon emission reduction benefit of bikeshare has obvious morning and evening peaks on workdays, while it tends to be stable without obvious peaks during the day on non-workdays. From the perspective of spatial distribution, the carbon emission reduction benefits of BS-FMMS are more significant in the metro station areas in the south of Baoan district, the west of Nanshan district, the central of Longhua district, and the south of Futian district in Shenzhen city, and the metro stations where the carbon emission reduction benefits of the non-workday are greater than those of the workday are mainly concentrated in Nanshan district, Futian district, and Luohu district. There is a significant positive correlation between BS-FMMS ridership and carbon emission reduction. These findings can provide clear policy implications for the decarbonization development of urban transportation systems.

Cover Picture: Geomechanics and Tunnelling 3/2024

AbstractIn Stockholm, Implenia builds of one of the world's deepest metro stations. This new metro station is an extension of the Blue Line to Södermalm. Beside the station single‐track tunnels for the subway, lift shafts, and a collateral service tunnel are constructed. Due to the difficult geological conditions and the bad quality rock, the AT – Pipe Umbrella System with squeeze connections were used to reinforce excavations and bolster safety during construction (photo: DSI Underground).

Examining the impact of station location on dockless bikesharing-metro integration: Evidence from Beijing

To address the unbalanced distribution of dockless bike sharing around metro stations, existing studies usually examine local-scale characteristics while neglecting the correlation between station location and travel demand which exert a more substantial influence on travel behavior. This study bridges this gap by conducting a comprehensively analysis of the impacts and underlying mechanism of station location on DBS-metro integrated demand. The results uncover a notable negative correlation between station location − measured by both proximity to the city center and distance from subcenters and DBS-metro integration demand. Moreover, job-housing imbalance and public transport allocation around metro stations, inherently influenced by station location, further shape DBS-metro integration demand. Notably, our results show significantly higher demand during the morning peak compared to the evening and at metro stations with medium-level ridership, highlighting the heterogeneous patterns. In addition, subcenters compensate to some extent for the decline in transport resources caused by distance from the city center. These insights bear critical implications for policy formulation concerning on-demand public transport services and the exploration of transport equity, facilitating a more informed approach towards rectifying transportation disparities.

Estimating pedestrian flows using route distributions and sparse counting data

At metro station Münchner Freiheit in Munich soccer fans cause congestion before and after soccer matches on the shortest route to get from a bus station to the metro. Yet, an online survey suggests that, given the right information and incentive through a mobile app, fans are willing to take a detour. In this study we combine the survey results with passenger counts collected in a field study to quantitatively estimate the number of rerouted pedestrians in dependency of influx from a side entrance for which there is no data. We find a realistic range for the change in flow, despite incomplete measurement data, that we use as input for predictive simulations. The quantitative results are also helpful for traffic management.

A pre-control method in safety risk management of metro construction

ABSTRACT With the rapid development of metro construction in China, construction safety accidents occur frequently due to the lack of effective safety risk controls. Continuously improving the level of safety risk pre-control has become a significant factor in the safety managements of metro construction. This paper presents a reasoning model for safety risk pre-control measures in metro construction using case-based reasoning. To establish the case database, a frame-based knowledge representation method is adopted based on the characteristics of metro construction safety accident cases. Additionally, a two-level retrieval strategy combining hierarchical retrieval and nearest-neighbor algorithms is used for case retrieval. Furthermore, a new approach, the cloud model, is proposed to determine the attribute weight of metro construction safety accidents. This approach addresses quantitative attributes with fuzziness and randomness. Finally, a specific metro station is taken as a case to validate the feasibility of the approach. The results showed that the case-based reasoning method enables engineers to quickly and effectively develop risk pre-control measures based on previous cases. In addition, the use of case-based reasoning in decision-making enhances knowledge sharing and reuse in the metro construction industry. This paper presents an effective reasoning approach for pre-control measure analysis in metro construction, allowing engineers to quickly and efficiently carry out scientific and reasonable pre-control measures from past cases.

Assessment of urban underground spaces inundation during extreme rainfall events.

As urbanization progresses and the impacts of climate change become more pronounced, urban flooding has emerged as a critical challenge for resilient cities, particularly concerning urban underground spaces where flooding can lead to significant loss of life and property. Drawing upon a comprehensive review of global research on underground space flood simulation and evacuation, this paper undertakes the modelling of inundation in a substantial underground area during the extraordinary rainfall event on 7 September 2023, in Shenzhen, China. Specifically, it introduces a two-step method to simulate the coupled surface-underground inundation process with high accuracy. The study simulates the inflow processes in three types of underground spaces: parking lots, metro stations, and underpasses. Utilizing the specific force per unit width evaluation, the research examines how varying flood barrier heights influence evacuation time and inundation risk. Subsequently, the paper proposes corresponding evacuation strategies based on the obtained findings. By highlighting the vulnerability of urban underground spaces to flooding, the study underscores the urgent need for further research in this domain.

Smart Water Dispensing: Enhancing Convenience Through App-Controlled Vending Machines

The demand for water vending machines has surged in India, particularly in urban Sectors like Airports, Metro station, malls, offices, Railway stations, Universities and other public sectors, where access to safe drinking water is a pressing concern. However, existing machines predominantly rely on digital and cash payments, posing challenges for individuals without smartphones or ready cash. To address this gap, we propose integrating a phone call facility into water vending machines, allowing users to make purchases via a simple phone call. Coupled with an integrated mobile application accessible nationwide, this system promotes inclusivity and convenience. By leveraging technology, we can ensure that clean water remains accessible to all, regardless of their digital capabilities or financial constraints, aligning with the principles of Digital India. Our goal is to address the challenge faced by individuals without access to cash or mobile phones. Through our in-machine phone call services, users can facilitate payments for others, promoting financial inclusivity. Additionally, our solution enables individuals worldwide to make payments seamlessly through a dedicated application.

Effect of Jointed Rock Mass on Seismic Response of Metro Station Tunnel-Group Structures

Effect of Jointed Rock Mass on Seismic Response of Metro Station Tunnel-Group Structures

INNOVATIVE TECHNOLOGY FOR THE CONSTRUCTION OF A PYLON STATION OF THE METRO BASED ON THE EXPERIENCE OF USING NATM

Purpose. For quite a long time, the metro station of the pylon type of deep contour interval was considered an underground structure that no longer has development potential. However, after the introduction of innovative technologies during the construction of the Dnipro metro, in particular the New Austrian Tunneling Method (NATM), this design is being used again and has developed further use. The purpose of the scientific article is to analyze innovations in the technology of construction of a three-vaulted pylon metro station from precast reinforced concrete using NATM, which require scientific justification. Methodology. In order to achieve the goal, the traditional technology of constructing a deep contour interval pylon station was revised. An analysis of the features of NATM, which allow it to be used during the construction of a pylon station in strong rock, has been carried out. A step-by-step analysis of the construction of the station was implemented with the involvement of mathematical modeling based on the finite element method. For this purpose, a number of finite-element models of each stage of construction of a pylon-type station have been created. After the numerical analysis, the indicated models were adjusted in accordance with the changes associated with the new construction technology. Findings. The value of the stress-strain state of the pylon station was obtained during the numerical analysis of each stage of construction. Stress analysis proves the possibility of applying innovative construction technology in the case of a pylon station. Originality. On the basis of the performed numerical analysis of the phased construction of a pylon station based on NATM, dependencies were obtained that allow revising the existing concept of the construction of this type of station in strong rocks. The obtained data justify the application of NATM and release the potential of the analyzed underground structure. Practical value. The substantiation of the innovative technology based on NATM allows expanding the scope of its application and successfully carrying out the construction of such complex underground facilities.

Construction of shallow buried large-span metro stations using the small pipe roof-beam method

Construction of shallow buried large-span metro stations using the small pipe roof-beam method

Optimization Study on Key Technology of Improved Arch Cover Method Construction for Underground Metro Stations Based on Similar Model Test

To enhance comprehension of the improved arch cover construction method for underground metro stations and provide guidance for future construction techniques and programs, the paper examines the indoor improved arch cover method of construction in the underground concealed excavation station of Tianhe Road Station of Guangzhou Metro Line 10, China. It includes a similar model test of the key technology and an analysis of the evolution law of the surrounding rock stress, the law of the ground settlement, and the law of the arch top deformation after the tunnel excavation. The study found that increased over-support can decrease arch settlement, with the maximum settlement occurring near the arch. Ground settlement typically occurs in the same areas as arch settlement, but arch settlement may occur earlier. The excavation of the arch cover has little impact on the overlying soil pressure, and the supporting structure is more effective in controlling soil deformation. The upper part of the arch cap experiences mainly extrusion stress, with the maximum stress occurring near the middle of the arch. The stresses in the arch’s base decrease significantly during the excavation of the side drifts but show an increasing trend during the excavation of the lower rock mass. The presence of the central column significantly affects both the settlement of the arch and the ground, as it bears most of the compressive stress of the arch. This stress decreases initially and then increases. The amplitude of deformation is more pronounced when the dismantled central column is closer to the middle of the arch.

Digital twin-based quantification of carbon emission from foundation pit construction: A case study of a station in Shanghai Metro

This study focused on achieving the carbon peaking and carbon neutrality goal. A carbon emission calculation method based on the entire process of excavation construction and the emission factor method for the foundation pit construction of a metro station was proposed. This method facilitated quantitative calculation of total carbon emissions in metro foundation pit engineering, which was then incorporated into a self-designed digital twin platform to drive sustainability efforts. The proposed calculation approach was verified in the foundation pit of Huangpi South Road Station (Shanghai Metro Line No. 14). (1) The pit construction process of the targeted metro station emitted 127,439t of carbon dioxide equivalent. (2) From the material perspective, reinforcing steel and concrete accounted for a significant proportion of the overall carbon emissions. Whereas, from the construction perspective, the engineering process of supporting structures accounted for a considerable proportion of the carbon emissions. (3) A comparative analysis of different construction zones revealed that the carbon emissions during the construction stage of the metro pit project were closely related to the amount of earthwork and size of the deep excavation engineering. Practically, the discovered knowledge of carbon emission characteristics can be visualized in a digital twin.