Elevated Metro Research Articles

Comprehensive analysis of the impact of elevated metro line infrastructure on the urban heat island effect in Chennai: A multi-model approach

This study is driven by the essential need to understand the dynamic urban heat island patterns in Chennai, particularly in light of the city’s significant expansion which resulted in the establishment of connectivity through the implementation of the elevated metro line infrastructure project. A notable gap in the current research landscape lies in the exploration of the impact of this recently introduced metro infrastructure on urban heat islands. Utilizing a multi-modal approach, the research incorporates remote sensing data, Land Use and Land Cover (LULC) patterns, mobile transect surveys along a segment of the metro stretch, and in situ data logging at three locations. The study reveals a strong correlation between mean Land Surface Temperature (LST) values and landscape metrics. The introduction of the elevated metro line resulted in a noteworthy decrease of 4.26 °C in UHI patterns in the month of May. It was also found that the varying land-use along the metro also plays an impact on average Surface Urban Heat Island Intensity (SUHII). The three elevated corridors demonstrate reductions in SUHII by 2.3 °C, 1.4 °C, and 1.3 °C. Mobile transect surveys indicate that afternoons show an average UHI Intensity (UHII) of 4.7 °C and 4.6 °C for road and metro-road scenarios, with the metro line exhibiting a comparatively lower UHII of 2.8 °C. Data logging reveals that the Metro_Veg (metro-line with vegetation on either side) scenario exhibits a more pronounced UHI effect compared to Metro_Build (metro-line with buildings on either side). Metro_Veg records the highest air temperature at 45.90 °C, followed by Metro_Build and Road_Veg (road with vegetation on either side) at 43.70 °C and 39.70 °C, respectively. The elevated metro structure provides shade on roads, resulting in the lowest surface temperatures in the metro scenario. Overall, the findings suggest that metro line infrastructure holds potential for UHI mitigation. While extending metro lines across every road may not be feasible, the study advocates for shading above roads as a practical mitigative measure. Future research can explore various structures and materials, including dynamic solutions, for mitigating UHI effects along urban roads, contributing to sustainable urban development.

Floor vibration predictions based on train-track-building coupling model

With the objective of rational urban space utilization, the development of elevated metro depots and over-track buildings is progressing rapidly, with a particular focus on addressing the vibrations caused by trains. Unlike traditional metro depots, trains in elevated depots run on concrete floors, which may lead to excessive floor vibrations. Therefore, it is essential to evaluate the impact of these vibrations during the design phase. In this paper, a vertical vibration prediction model for trains running on building floors is proposed by integrating the train, track structure, and building structure into a unified system. The train model is conceptualized as a multi-rigid body connected by springs and dampers. The track structure comprises rails, fasteners, and track slabs. The building floor is simplified as a rectangular plate composed of multiple orthogonal structural girders and columns in vertical contact with the floor. To verify the proposed method, field measurements were conducted in an elevated metro depot. The proposed model provided estimates of the vibration transmission with good agreement from track to building floor by comparing with the measured vibrations. The model presented in this paper can be utilized to predict the base vibrations of buildings and further predict the floor vibrations.

Technoeconomic analysis of rooftop PV system in elevated metro station for cost-effective operation and clean electrification

Metro system constitutes an essential component of urban transportation infrastructure, simultaneously serving as a significant energy consumer and carbon emitter. Integration of rooftop PV systems in elevated stations can effectively mitigate carbon emissions and enhance the utilization rate of clean energy. Nevertheless, current research rarely explores the application and feasibility analysis of rooftop PV systems in elevated metro stations. To address this research gap, the study investigates potential of rooftop PV systems applied in the elevated stations, and optimizes the PV scale and battery capacity for achieving the maximum net present value. The results show that the optimized photovoltaic-battery (PVB) system can bring about a PV self-sufficiency (SS) of 0.54, in the baseline scenario. For the entire line, SS can achieve 0.26–0.59 with the integration of PVB systems. Furthermore, the impact of skylights on energy consumption for illumination and PV power generation is discussed, and the PV potential of skylights is investigated. The results show that PV skylights lead to an increase a rise in the SS of 8.6%–15.3%. This study contributes reference for the potential of PV systems on elevated stations and for cost-effective operation and clean electrification of the urban rail transit sector.

Study on Elevated Interval Evacuation of Metro Train considering the Influence of Fire, Railings, and Track Bed

Elevated metro is a typical type of urban rail transit that operates on viaducts. Due to its fast construction speed and low cost, it plays an important role in transportation systems with dense concentrations of people. Once a fire accident occurs in rush hour, it will cause high casualty and enormous injuries. In this regard, studying the characteristics of fire smoke spread and passengers’ evacuation is of profound significance. In this paper, Pyrosim and Pathfinder software was utilized to simulate metro fire and evacuation process. The variation of temperature, CO concentration, and visibility inside carriage and outside walkaway were studied to explore the characteristic of fire and smoke. Evacuation time, speed, density, and path were analyzed for six cases considering the influence of railing settings on evacuation walkaway and the use of track bed. The impact of smoke on movement speed reduction and temperature on the available door numbers were taken into consideration. Results revealed that the temperature of accident carriage rose to tenability limit after 50 s and the visibility decreased to 5 m within 150 s. CO concentration was below safety criteria due to sufficient oxygen. Temperature was the most important factor that leads to the risk of evacuation, especially inside the accident carriage. The length of evacuation walkaway could highly reduce evacuation time and density. Railings had a negative impact on evacuation while the usage of track bed had a positive effect. Besides, the impact of railings was not as significant as the usage of the track bed. Research results can provide decision‐making reference for fire protection and evacuation design to alleviate congestion and improve safety management.

Development of Empirical Equation to Estimate Corridor Speed of Vehicles in Metro Construction Work Zone

Abstract Construction of elevated metro line leads to a reduction in the average speed of vehicles due to congestions, diversions, and road incidents. This reduction in speed depends on recurring (e.g., congestion in rush hours) and non-recurring (e.g., road accidents) delay factors. Non-recurring factors involve incidents such as accidental bus stops, pedestrian crossings, or clearing debris from road, etc., some of which may occur at very short notice. This research paper presents a case study of Pune Metro Rail Construction (Corridor II) in India for developing an empirical equation to estimate corridor speed of vehicles in metro construction work zone. Observations were recorded in spatial and temporal zones using floating car method through video recordings and traffic count using manual method. Based on the traffic behavior pattern, five non-recurring delay factors (NRDFs) were defined, namely vehicles in lateral entry, slow moving vehicles, vehicles in the wrong direction, on-street parked vehicles, pedestrian interference and their correlation with speed of vehicles was tested. It was concluded that these factors have a strong negative correlation with the speed of the test vehicle. To estimate corridor speed with given NRDFs, nonlinear equation was formulated using empirical evidence and validated using larger simulated data.

Leveraging cost-effectiveness of photovoltaic-battery system in metro station under time-of-use pricing tariff

As the cornerstone of contemporary urban transit infrastructure, the metro rail transit system significantly contributes to both energy consumption and carbon emissions. Recognizing the potential of rooftop photovoltaic (PV) applications in elevated stations to mitigate the carbon footprint of the metro system, harnessing this potential becomes imperative for advancing toward a cleaner future in the metro transit sector. However, the techno-economic feasibility of the rooftop PV application in elevated metro stations has not been fully reported in existing literature. Addressing this research gap, our study delves into the impact of the photovoltaic-battery (PVB) system on energy conservation and economic benefits within the elevated stations of a metro line in Beijing, China, and a multi-objective nonlinear mixed-integer programming (MIP) is formulated under a 3-tier time-of-use tariff scheme for minimizing grid load and maximizing economic benefits. The results demonstrate that the incorporation of both the battery energy storage device and the PV subsystem leads to an 8.3% and 19.2% reduction in annualized costs, respectively. When applied across the entire metro line, the PVB system is anticipated to yield a substantial annualized cost reduction ranging from 26.1% to 47.8%. Moreover, outcomes from the multi-objective MIP optimization reveal that the simultaneous achievement of economic benefits maximization and grid load minimization is infeasible, and the weighted sum method offers a decision-making platform for investors to choose one option or another according to extra criteria.

Assessment of Risks Associated with Elevated Metro Rail Projects by using Fuzzy Failure Mode a nd Effect Analysis

Assessment of Risks Associated with Elevated Metro Rail Projects by using Fuzzy Failure Mode a nd Effect Analysis

Assessing the Social Costs of Mixed Transport Systems with a Dominance of Motorcycles

When undertaking strategic planning to identify potential options for a detailed assessment, it is important to compare the total costs of existing mixed transport systems with the introduction of different new public transport (PT) modes. Hence, this study develops a social cost model for situation of mixed transport system which has a dominance of motorcycles where a new PT technology (e.g. Bus Rapid Transit - BRT, Monorail or elevated Metro) or an exclusive bus lane is being considered. The innovative aspects of this research are to develop equations to estimate the average operating speed of each mode and to the allocation of infrastructure costs to several transport modes sharing the facilities in motorcycle dominated mixed traffic environments. Based on a four-lane per direction mixed traffic corridor in Hanoi, Vietnam, the results show the lowest average social cost (ASC) mixed transport systems for different ranges of demand. Moreover, all mixed traffic options with BRT, Monorail, elevated Metro or exclusive bus lanes are better than the existing situation in terms of ASC and it is suggested that their feasibility is examined in a detailed assessment. The mixed transport social cost model can be modified to suit other local conditions where conventional bus, car and motorcycle share facilities and a new PT mode is operated. Additionally, transport planners and decision makers in such local situations, which are particularly common in South East Asia, can draw on the findings of this study.

Energy consumption characteristics and rooftop photovoltaic potential assessment of elevated metro station

The current trend of urbanization has spurred the growth of the urban railway transportation sector, leading to increased carbon emission and environmental challenges. Applying renewable energy assisted power supply systems into metro stations is a feasible method for achieving decarbonization in urban transit systems. This study comprehensively reveals the real energy profile of a metro station on an hourly scale and establishes a multi-objective model to investigate the energy flexibility of the metro station with integrated battery energy storage for on-site renewable electricity consumption maximization. The results show that the elevated station has a photovoltaic potential of 20 %–25 %, in terms of self-sufficiency rate, when the rooftop of the station is fully utilized for photovoltaic array installation. Moreover, a photovoltaic-battery system in addition to a multi-objective mixed inter linear programming model is presented for the circumstance, there existing idle land around the station, to achieve a near-zero carbon station. It is indicated that the near-zero carbon station can be achieved with a minimum payback period of 11.5 years by optimizing the photovoltaic array size and battery storage capacity, leading to the annual carbon emission reduced from 457.1 to 91.4 tons. It is anticipated this study could provide reference for clean electrification and decarbonization in urban metro system.

A comparative economic assessment of urban transport infrastructure options in low- and middle-income countries

Several innovative public transport (PT) projects have been developed in low- and middle-income countries (LMICs), where cars, motorcycles and buses share the facilities. However, there seems to be very little evidence on assessment methods to analyse the feasibility of different PT modes and identify the most cost-effective mixed transport system. To address this issue, this study develops a comparative economic assessment (CEcoA) based on the PT technologies’ characteristics and the conditions of local transport networks. The assessment integrates four models. First, a social cost model (SCM), that calculates the social costs of each mode and mixed transport systems, is the key model in the assessment. Second, an incremental elasticity analysis (IEA) evaluates changes in total demand by using the demand elasticity with respect to a composite cost. The IEA solves the first drawback of the SCM that demand is assumed to be fixed. Third, an incremental logit model (ILM) estimates changes in modal shares with respect to generalised costs. The ILM overcomes the second disadvantage of the SCM, where preferences of users for all alternative transport modes are not considered. Fourth, a microscopic simulation model (MSM) simulates all existing transport modes’ flows on the local network. The MSM solves the third drawback of the SCM, which only considers an isolated corridor without any interaction between the different modes and any junctions. The assessment was applied to compare an existing mixed transport situation and twelve options with an introduction of new PT technologies (Bus Rapid Transit - BRT, elevated Metro and Monorail) replacing the existing bus services; either wholly or partially, and with or without a congestion charge scheme for private transport (PRV) on a corridor in Hanoi, Vietnam in terms of average social cost (ASC), total demand and PT share. The results show that eight options with BRT or Monorail or Metro are feasible, whilst the BRT option that replaces all existing buses and includes congestion charging is the best alternative in terms of ASC. Transport planners and decision makers can draw on the findings of this research. A congestion charge scheme might be considered for the local conditions to meet specific objectives such as a reduction in ASCs and an increase in modal share of PT. The CEcoA can be a strategic tool for not only planning new PT technologies on corridors in the whole network but also retrospectively evaluating investments of PT modes. Moreover, the methodology of the CEcoA might be applied and modified to various transport networks with an abundance of motorcycles to assess the costs and benefits of new PT modes and mixed transport systems with or without the congestion charge.

EXAMINATION OF METRO STATIONS PEDESTRIAN ACCESSIBILITY FOR ALL USING OPEN DATA KIT: A CASE STUDY OF NOIDA CITY IN INDIA

Abstract. To make transit rail services more attractive, the preferred public travel mode and serve as the backbone of any metropolitan area, there arises a need to create a sustainable and inclusive urban environment with access to all. This study aims to map the pedestrian permeability and impermeability by categorizing roads and streets around identified transit nodes in Noida as public, private and non-accessible by all. By doing so, the study identifies very distinct and spatial divisions like gated communities and urban villages that have emerged as social ghettos in the planned city Noida and thereby, devoid it of being an inclusive city. Initial metro station smart android-based mobile surveys were done across 12 elevated metro stations falling on the blue transit corridor line connecting Delhi with its satellite town Noida using smart apps namely ODK and Kobo Toolbox with the analysis done in QGIS. It was found that trip distance and time had a strong association with walking while age, gender and purpose of the trip had no association with walking to the metro station. Most transit users living within one-kilometer walking distance prefer to walk to the nearest metro station in Noida. Finally, the study shows the area difference between the perceived and actual Isochrones prepared in QGIS as Ped-sheds after deducing areas such as gated communities, superblocks and unplanned settlements like urban villages where the existing road/street network is not accessible by all or safe to use.

Seismic Analysis of Elevated Metro Bridge

Abstract: A metro rail system is more preferred type of metro system due to ease of construction and also it makes urban areas more accessible with very less construction difficulty. metro concept is very easy to transport large numbers of people and transportation. In metro city like Delhi, Kolkata, Chennai and Mumbai is very populated city An elevated metro system has two major elements pier and box girder. The codes are now moving towards a performance-based (displacement-based) design approach, which consider. All the information are given by MMRC and considered the data value in this design as per the target performances at the design stage. Which is located to ShyamNager metro station in Mumbai, The present study focuses on pier of an elevated metro structural system conventionally the Double Decker pier of a metro bridge is designed using a force based approach. During a seismic loading, the behaviour of a single pier elevated bridge relies mostly on the ductility and the displacement capacity. It is important to check the ductility of such single piers. Force based methods do not explicitly check the displacement capacity during the design. The codes are now moving towards a performance-based (displacement-based) design approach, which consider the design as per the target performances at the design stage. Performance of a pier designed by a Direct Displacement Based Design is compared with that of a force-based designed one. The design of the pier is done by both force based seismic design method and direct displacement based seismic design method the study.

Risk assessment of underground and elevated metro projects from clients' and contractors' perspective

PurposeIndia is a rapidly urbanizing developing country with a population of 1.4 Billion. Indian governments have invested USD 50 Billion) in metro rail projects in 18 cities. Metro constructions are multi-stakeholder mega-projects and are prone to a variety of risks. The purpose of this paper is to analyze the risks involved in metro rail construction projects in a densely populated developing country for two types of systems and from two perspectives. Current literature lacks an understanding of similarities and differences in the risks involved in underground and elevated metro projects from clients' and contractors' perspectives, which the paper highlights.Design/methodology/approachA total of twenty-five risks were identified, categorized and assessed through experts' opinions about the impact and probability of occurrence of the risks through a questionnaire-based survey. The survey respondents included experts in metro rail construction from client and contractor sides. Paper uses a Fuzzy Inference System to calibrate risk magnitude from occurrence probability and impact.FindingsA notable difference was observed in the views of clients and contractors, except for certain common risks. Both stakeholders had different risk perceptions for the underground and elevated metro rail systems.Practical implicationsThis study contributes to the risk assessment for different types of metro systems. This research can help policymakers as well as consultants in prioritizing their risk management strategies in developing countries like India.Originality/valueHighlighting the critical aspects of risks in metro projects in a developing country, this paper also provides system-based and stakeholder-based comparative aspects of risk analysis.

A Sustainable approach to reduce Embodied and Operational Cooling Energy for an Elevated Metro Rail Station of Ahmedabad, India, using Building Information Modelling (BIM) and Factor Comparison Method

A Sustainable approach to reduce Embodied and Operational Cooling Energy for an Elevated Metro Rail Station of Ahmedabad, India, using Building Information Modelling (BIM) and Factor Comparison Method

Numerical study of pollutant exposure of urban street canyon buildings

The computational normalised pollution concentration profiles along the height of the street canyon are discussed to evaluate the pollutant exposure to buildings facing urban street canyons. With the help of three-dimensional numerical simulations performed using computational fluid dynamics approach, the effects of EMRT on pollution dispersion are analysed onthe both side walls of the canyon of aspect ratio ‘one’. The exposure of pollutant on buildings on both the sides of street canyon has been discussed. The RANSequation equipped with the renormalization group, turbulence model and Species Transport Model are adopted. It has been found that for first 25% of the height of street canyon, introduction of elevated metro rail track (EMRT) respectively increases and decreases normalized pollutant concentration for leeward and windward side walls. For the remaining upper portion of the street canyon, the introduction of elevated metro rail track leads to decrease in the pollutant concentration. Introduction of EMRT leads to increase in pollutant concentration on the leeward side wall in its lower region. This increase is especially significant at the pedestrian level at the centre of the street canyon’s length. In the present work, the mass fractions of the pollutants on leeward and windward side walls are also investigated and comparison of mass fraction between street canyon with and without elevated metro rail track has been discussed.

Selection of Sustainable Materials for Energy Savings of Infrastructure-Transportation Project in Ahmedabad, India Using BIM and FCM

This study aims to develop a methodology for the selection of sustainable building materials for the reduction of embodied and operational energy for a complex infrastructure transportation project, i.e., elevated metro rail station of Ahmedabad, India by application of building information modelling (BIM) and factor comparison method (FCM). Evaluation of the alternative building materials and designs to obtain the best energy efficiency has been carried out using Revit Architecture 2018 and Green Building Studio. The achieved average embodied energy savings is about 73%, which is by the suggested alternative materials instead of existing ones. By application of FCM, which is a multi-criteria decision making (MCDM) technique, it has been observed that the polished Kota-stone flooring, stone-floor tile cladding, toughened fibre-glass ceiling and insulated fibre-glass door appear to be the most feasible sustainable material for flooring, wall cladding, ceiling, openings and fenestrations for the design of the metro rail station box in Ahmedabad, India. This study contributes significant knowledge in the field by highlighting the application of BIM as a tool for sustainable development and recommends a few alternate building materials and sustainable designs which would result in the reduction of energy usage for the metro-rail-station and other building structures leading to a sustainable future.

A Case Study of Constraint Cross-Passage Construction in Urban Tunneling

Abstract: The paper aimed at a detailed case study of cross-passage, which is forced to design and construct by connecting the station box and main tube tunnel of Marol Naka station in Mumbai Metro Line 3, since the marol Naka is densely populated area and elevated metro line is passing over an underground station, therefore further excavation of tunnel is done through the cross-passage. In these station, the cross- passage is constructed for public utilities for connecting the station box to the platform and also for the emergency exit. During tunnel construction, the cross passage is excavated after the main tunnel has been constructed. At the same time, the safety of the cross passage and the stability of the tunnel must be ensured by instrumentation and monitoring. Design of the cross- passage is achieved according to the principles of “New Austrian Tunnelling Method’ (NATM) and the composite lining structure is adopted. NATM is used to widen the station platform which is initially tunnelled by the TBM. The dimension of 230m long and 15m wide Marol Naka station has 16 cross-passages which are constructed connecting the station box to the platform; the observations and the designing part- Finite Element method is used in order to evaluate stress deformations induced on the cross-passage. Keywords: Cross passage, NATM, TBM, Finite element method, Marol Naka station, Emergency exit.

Application of integrated fuzzy FCM-BIM-IoT for sustainable material selection and energy management of metro rail station box project in western India

Fuzzy Factor Comparison Method is a paired comparison-based Multi-Criteria Decision-Making method which can be effectively applied for selection of the best feasible alternative among a set of available alternatives. This paper aims at developing a methodology by application of fuzzy Factor Comparison Method for selection of most feasible, sustainable material for the design of floor, ceiling, walls, cladding, openings and fenestrations for an infrastructure transportation facility like metro rail station box of Ahmedabad, India. Results of fuzzy Factor Comparison Method reveal that polished Kota stone tiles, toughened fibreglass ceiling, Kota stone wall tiles and insulated fibreglass door appear to be the most feasible sustainable materials. Evaluation of the alternative building materials and design strategies was carried out through Building Information Modelling, and the observed results show 73% of average embodied energy savings achieved by the suggested alternative materials instead of the existing ones. Furthermore, this study also proposes a framework for real-time automated Building Information Modelling-enabled energy management system for the elevated metro rail station by the Internet of Things sensors. It has been observed that more than 25% of the operational cooling load can be reduced by the proposed integrated Building Information Modelling-Internet of Things framework. This novel approach plays a key role in the sustainable future of infrastructure projects.

Assessment of Noise Pollution of Kolkata Metro Railway System and Its Impact on Urban Receptors A Case Study

An assessment of noise quality was conducted at underground and overground metro stations, within the metro rakes (AC and Non-AC) and at an institutional building near elevated metro corridor to assess the exposure of Kolkata Metro Railway System. The present study was conducted in different hours (peak and non-peak hour) for different types of rake (AC and Non-AC) movement. Different noise descriptors including A-weighted equivalent noise (Leq), statistical noise (L10,L50,L90), noise climate (NC), traffic noise index (TNI), two hour noise dose (%ND) and corresponding time-weighted average (TWA) were calculated under the purview of the present study. Pearson’s correlation was performed between all noise descriptors to investigate the relation between them. Scatter plot analysis was conducted between L10 and %ND. In case of all study duration, all noise descriptors mostly exceeded FTA prescribed noise standard, along with 2-hr TWA which exceeded the OSHA guidelines of 100 dB for both AC and Non-AC rakes. On the other hand, at underground and overground metro stations, within metro rakes (except at day peak hour within AC coach) and at school building, mean value of traffic noise index (TNI) exceeded 74 dB (A), the threshold of over criterion. The study results indicate that Non-AC rakes are more annoying than AC-rakes. In all the study units, Leq was influenced by L10, which originates from pressure honking. There is very strong relationship observed between L10 and % ND. This study proposes that noise barrier should be installed at underground and overground metro stations, along the stretches of overground metro track, within metro rakes for developing the acoustic quality of Kolkata Metro Railway System and the areas of its immediate vicinity.

Development of integrated cloud-based Internet of Things (IoT) platform for asset management of elevated metro rail projects

This paper aims at developing an integrated cloud-based internet of things (IoT) platform for asset management of elevated metro rail project. This platform will provide information about the various assets of the project and its location in real time which will be helpful in better management of assets. Furthermore, prototype of the platform is developed in which sensors are embedded on assets for traceability and its information can be directly accessed by stakeholders through this web based application. This platform will help reduce the amount of errors in information management. Also this would enhance collaboration amongst the various stakeholders of the project. It has been observed that by using this platform the paper works pertaining to the record keeping during the process of segment production and segment transportation can be reduced by about 30%. Furthermore, the cycle time for casting and transportation of each precast segment can be reduced by about 17% and 50% respectively. This indicates that there is an improvement of production efficiency. The results of the prototype conclude that the platform is feasible for application at construction sites for real time monitoring and management of assets.