Metro Project Research Articles

ASSESSING COLLUSION RISKS IN MANAGING CONSTRUCTION PROJECTS USING ARTIFICIAL NEURAL NETWORK

Being an insidious risk to construction projects, collusion has attracted extensive attention from numerous researchers around the world. However, little effort has ever been made to assess collusion, which is important and necessary for curbing collusion in construction projects. Specific to the context of China, this paper developed an artificial neural network model to assess collusion risk in construction projects. Based on a comprehensive literature review, a total of 22 specific collusive practices were identified first, and then refined by a two-round Delphi interview with 15 experienced experts. Subsequently, using the consolidated framework of collusive practices, a questionnaire was further developed and disseminated, which received 97 valid replies. The questionnaire data were then utilized to develop and validate the collusion risk assessment model with the facilitation of artificial neural network approach. The developed model was finally applied in a real-life metro project in which its reliability and applicability were both verified. Although the model was developed under the context of Chinese construction projects, its developing strategy can be applied in other countries, especially for those emerging economies that have a significant concern of collusion in their construction sectors, and thus contributing to the global body of knowledge of collusion.

What Drives the Rise of Metro Developments in China? Evidence from Nantong

This paper addresses to the rapid rise of metro developments in Chinese cities to reconsider the official justifications of such mega-projects and the underlying driving forces behind proposal and approval processes. Qualitative approaches were undertaken in this in-depth case study of Nantong’s metro project, through insights into planning documents and evidences gathered from interviews, together with relevant socioeconomic data. Our research findings reveal four major motivations to develop metro projects in China: the city’s expected improvements through the metro system, the local economic power as the essential requirement and source of confidence for project development, the inter-city competition as an invisible factor driving project proposals, and the changing domestic political economy as the direct cause of its approval. As a topic that is frequently studied in the relevant literature and often advocated by metro projects promoters, the local expected achievements in terms of modal shift to public transport, transit-oriented development, economic growth, and tax maximisation are highlighted in this case study. Additionally, in China, inter-city competition and economic-political reasons involved in initiating, promoting, and approving urban mega-projects are also vital to the whole process.

METRO AS AN INNOVATIVE INFLUENCE ON EGYPTIAN CULTURE

This research is an introduction to the attempt to understand and explain the metro project as one of the influences on the Egyptian human culture in terms of being an artificial mechanic that is characterized by strict determinants, as it is a new party to the reciprocal relationship between culture and urbanization, and its stations are service buildings that receive millions of citizens, The Greater Cairo Metro network aims to connect the governorates of Cairo, Giza and Qalioubia with a fast and secure means of transport to serve more than four million people daily. It works to save many hours of work and production lost in the traffic. Most people have confirmed through daily newspapers that life in Cairo is paralyzed by the disruption of the metro, which underscores the importance of the project.Thus, the metro has greatly influenced the culture of society in the Greater Cairo Governorate. The relationship between the users and the metro is a reciprocal relationship that stems from the functional and daily service of the society with different ages and different categories، whether male or female, in childhood, youth or even the elderly.In order to achieve the previous objective، the aim was to study some of the theoretical and scientific concepts related to the subject through the concept of culture and its constituents, as well as to study the reciprocal relationship between Egyptian culture and urbanization, as well as monitoring the cultural impact and summarizing it in the form of negatives and positives. Through sample questionnaire and interviews with users, and then reach the results and recommendations of the search.

Evaluation of evacuation methods in underground metro stations

The evacuation process is a key part of the emergency response strategy to manage and control a variety of emergency situations or disasters. Many regulations and standards have been put into effect in order to ensure both the proper workplace design and the efficient evacuation procedure. This is something that is passing on to the underground space design, a critical urban infrastructure with special needs and requirements. The paper analyses the evacuation process and its performance in an underground metro station that is under development in Greece, as part of the Thessaloniki metro project. This is achieved by following the guidelines set by the NFPA design guidelines, in terms of users load and concentration, travel speed and maximum allowable time to reach a point of safety. In addition to that - and beyond static hand calculation numbers - the evacuation process is simulated through the use of the Pathfinder software package, under a number of scenarios regarding occupants’ speed and exit route availability. Both methods are evaluated over several parameters such as results efficiency and type, scenario management. Results show that the major advantage of computer modelling evacuation is the ability to assess conditions and parameters such as worst case scenario, critical occupants’ average speed and the influence of exit choice in evacuation time.This allows for the overall assessment of the critical conditions that might occur during the evacuation and the overall safety of the underground space users.

Knowledge dynamics-integrated map as a blueprint for system development: Applications to safety risk management in Wuhan metro project

Abstract Safety has always been a persistent problem in the construction industry, particularly for tunnel construction projects due to the inherent uncertainty in geotechnical conditions and the complexity of the tunnel construction process. Literatures and practices highlight the importance of safety knowledge to the construction safety. However, safety knowledge is not always provided in a convenient and timely manner. This paper develops a Knowledge-dynamics Integrated Map (KIM) to visualize safety knowledge flow in tunnel construction safety risk management. The KIM highlights the what, the who, and the why of knowledge flow by portraying its dynamics associated to the working processes. With the use of KIM, the safety knowledge flow barriers are identified so that knowledge flow facilitators can be designed. The KIM has been applied in Wuhan metro project as a blueprint for systematically developing effective safety knowledge management systems.

Karst‐induced sinkhole detection using an integrated geophysical survey: a case study along the Riyadh Metro Line 3 (Saudi Arabia)

ABSTRACTNowadays, most planned large infrastructure projects increasingly use multi‐technique geophysical methods integrated with geotechnical surveys to assess detection and exploration of karst‐related systems. This article focuses on the case of a large sinkhole found during the geophysical surveys that were carried out along Riyadh’s new Metro Line 3 (Saudi Arabia). This line is the longest (41 km) of the six that are currently under construction in the framework of the largest public rail infrastructure project, the Riyadh Metro Project (176 km).A multi‐technique geophysical survey combining seismic (1040 m of seismic refraction tomography and four downhole tests), electrical (1035 m of electrical resistivity tomography), and electromagnetic methods (1040 m of ground penetration radar) was conducted to shed light on the subsurface geology along the section of this case study. The combination of the geophysical methods led to early identification of a subsurface area of lower resistivity and seismic velocity than the background values of the carbonate bedrock. It also revealed smaller fractures that could lead to future sinkhole formation. A subsequent dense investigatory borehole grid (14 boreholes, five probeholes, 38 standard penetration tests, nine TV‐logging, and five pressuremeter tests) further confirmed the presence of a buried sinkhole.This paper shows the results of each individual geophysical method as well as the final geotechnical interpretation based on the combination of geophysical methods with borehole drilling. It concludes that the use of a single method for karst assessment, whether a geophysical method or borehole drilling, does not allow a sufficiently detailed geotechnical profile of the ground. This case study provides basic guidance on the most suitable and accurate techniques to detect similar karstic features across Riyadh.

Critical Success Factors in Implementation of Urban Metro System on PPP: A Case Study of Hyderabad Metro

Rail-based metro system is crucial for supporting a city’s expansion and growth. However, urban metro projects being capital intensive with long gestation and pay back periods may not be financially viable but socially desirable. More and more cities in India are announcing metro projects committing huge budgetary resources to these projects at the cost of sectors such as health and education. Given the huge requirement of capital and possibility of attracting willing as well as capable private investors to undertake urban transport projects, promoting public–private partnerships (PPPs) could be a key priority. However, none of the metro projects launched during past 7 years in India have been planned on PPP framework. International experience in PPP metro and our own Delhi airport metro experience have demonstrated that many issues can influence the successful implementation of PPPs in such projects. In this context, outcome of Hyderabad metro is keenly watched as it is one of the largest metro rail projects built under a PPP framework anywhere in the world. The paper reviews the research conducted on critical success factors (CSFs) that are necessary for adopting PPP models in urban metros in Indian context. Eighteen CSFs identified through literature survey have been validated in a pilot study through structured questionnaire and grouped in seven macro-factors through hierarchical cluster analysis. A case study has been attempted using SAP–LAP framework to analyse the identified CSFs in real-life settings of the first two stages of Hyderabad metro project. Key players working on the project were interviewed during a field study to gather feedback on actions they took on factors critical to success. Observations and findings have been synthesised as learnings for future such projects.

Swimming or Drowning in the Depths of Partnership

AbstractThis exploratory research paper seeks to consider the problems that may arise in the process of creating deep and lasting partnerships in public‐private partnerships (PPPs). It does this by contrasting two case studies of very different PPPs, Copenhagen's metro project and Melbourne City Link. The paper puts forward the case for the author's concern that a deep partnership could lead either to mercantile government or quasi‐governmental private parties and thus lead to a diminution of the benefits of PPPs. The paper concludes that these concerns are relevant and need to be considered and guarded against no matter the contract conditions.

Estaciones enterradas de la línea 3 del Metro de Riad. Estaciones profundas con contrabóveda

The deep stations with counter-vault of Riyadh Metro Project Line 3 are formed by four underground levels that constitute the deep box, where a central atrium configures all passenger flows. The temporary works consist of a bottom-up construction method. In one station, a continuous retaining wall has been designed based on secant piles with three retaining levels. The bottom slab of the deep box is a reinforced concrete counter-vault with continuous shear keys that resist the water pressure transmitting the axial compressive forces to the rock (arch mechanism). The intermediate and top levels have been designed with precast pre-stressed beams and concrete in-situ slabs, with an evolutional structural behaviour.

“Making It Happen”: Deciphering Government Branding in Light of the Sydney Building Boom

“Making It Happen”: Deciphering Government Branding in Light of the Sydney Building Boom

Comparison of NATM and umbrella arch method in terms of cost, completion time, and deformation

In all kinds of tunnel excavations, especially those excavated in cities, it is important to control surface settlements and prevent damage to the surface and subsurface structures. For this purpose, in weak rocks and soils, the umbrella arch method (UAM) has been used in addition to the new Austrian tunneling method (NATM). NATM and UAM are the best-known classical methods used in tunnel excavation. In classical tunneling, NATM is usually preferred in normal rocks. However, in some cases, NATM may be insufficient. UAM is a very effective alternative especially in soils and weak rocks. In soil and weak rocks, UAM is especially necessary to prevent excessive deformations. Selection of UAM or NATM is based on the following factors: cost comparison of NATM and UAM, allowable deformations, quality of rock or soil, application time of NATM and UAM, availability of skilled workers, and qualification level of the workers. Therefore, selecting the excavation method in these kinds of grounds is vital in terms of achieving the project goals in time, managing the project costs effectively, and controlling the probable deformations on nearby structures. A critical issue in successful tunneling application is the ability to evaluate and predict the deformations, costs, and project time. In this paper, application times, costs, and deformation effects are compared between NATM and UAM in sensitive regions at the Uskudar-Umraniye-Cekmekoy metro project (UUCMP). Also, efficiency of the deformation control of UAM is demonstrated by using the 2D numerical analysis method. UUCMP is part of the Istanbul metro network. The tunnels have a cross section of 75.60 m2 for NATM and 83.42 m2 for UAM. Geology in this section is composed of weak sandstone. Diabase and andesite dykes are also rarely observed. This study shows that the construction cost of UAM are 1.7 times more expensive than NATM. Although application time of UAM is 2.5 times longer than NATM, it is 2.5 times more efficient in controlling the deformations. This efficiency in controlling the deformations is confirmed via two-dimensional numerical analyses.

Public Perception of and Attitude to Driverless Train: A Case Study of Sydney, Australia

There are 32 cities around the world with automated metro systems in operation. The majority of these are located in Europe (13) and Asia (14) but none so far in Australia. However, the picture is changing in 2019 when the first stage of the ‘Sydney Metro’ starts its operation on the North West link in Sydney, New South Wales, Australia. The automated train is planned to be used safely without human interaction, thus reducing significantly the labour input in the provision of service. Although the proposal for a fully automated system came late in the planning phase of the Sydney Metro project, it appears that, from a technical point of view, the project is clear and well planned. However, providing information to Sydneysiders and understanding their attitudes towards automation has received no consideration. Moreover, how the public perceive these changes and their attitudes to aspects of the new system, including driverless trains, may well be crucial in properly positioning and marketing the new services to ensure the expected patronage. This paper aims to fill this gap by investigating public opinion of the new Sydney Metro service by undertaking a research on people’s perceptions of a driverless train as well as their attitudes to the new transport system and public transport more generally

Traffic management of mega infrastructure construction projects: Success story and lessons learned from the riyadh metro project

Traffic management of mega infrastructure construction projects: Success story and lessons learned from the riyadh metro project

Rock Grouting in Copenhagen Limestone – The Cityringen Experience

Extensive rock grouting has been carried out during the construction phase of the Cityringen Metro Project. The main goal of the rock grouting has been to reduce the permeability in the rock by filling joints, cracks and fissures, in order to minimize the groundwater inflow during excavation of caverns, pump sumps and TBM break in/out through the stations/shafts. Both horizontal and vertical grouting has been performed above and below the water table, with unique challenges and advantages/disadvantages. The grouting has been performed as up-stage, where the grout hole is drilled to full depth and then grouted from the bottom and up in stages using a pneumatic packer. The split-spacing method has been used to expand the grouting pattern if needed after primary grouting campaign has been finished and tested. The article describes, through case histories, the achieved results, challenges and limits of the applied methods, including future recommendations. The rock characteristics of the Copenhagen limestone, in regards to the performed rock grouting, are also discussed.

A hybrid finite element and surrogate modelling approach for simulation and monitoring supported TBM steering

The paper proposes a novel computational method for real-time simulation and monitoring-based predictions during the construction of machine-driven tunnels to support decisions concerning the steering of tunnel boring machines (TBMs). The proposed technique combines the capacity of a process-oriented 3D simulation model for mechanized tunnelling to accurately describe the complex geological and mechanical interactions of the tunnelling process with the computational efficiency of surrogate (or meta) models based on artificial neural networks. The process-oriented 3D simulation model with updated model parameters based on acquired monitoring data during the advancement process is used in combination with surrogate models to determine optimal tunnel machine-related parameters such that tunnelling-induced settlements are kept below a tolerated level within the forthcoming process steps. The performance of the proposed strategy is applied to the Wehrhahn-line metro project in Düsseldorf, Germany and compared with a recently developed approach for real-time steering of TBMs, in which only surrogate models are used.

Identification of woods dating back to the Neolithic Age released from the YENİKAPI (İSTANBUL) excavations

Many ruins dating back to the Neolithic Age have been unearthed at Yenikapi during the archaeological excavations carried out as part of the Marmaray Metro Project. Wood samples of these ruins were sectioned via freezing sliding microtome. These sections became permanent slides and they were compared with reference to slides, wood identification atlases and books in order to identify their taxa. Only 240 samples could be sectioned from among 430 wood samples. As a result of the identification, the following were determined: Quercus spp., Q. pontica, Juniperus spp., Ficus spp., Juglans spp., Fraxinus spp., Alnus glutinosa, Abies spp., Salix sp., Acer spp., Ulmus spp., Castanea sativa and Taxus baccata.

A model to predict daily advance rates of EPB-TBMs in a complex geology in Istanbul

This paper summarizes the results of a research study carried out to create a model to predict daily advance rates of EPB-TBMs in a complex geology in Istanbul. The model is based on the analysis of the accumulated data obtained from several projects. The model is first tested for Uskudar-Umraniye–Cekmekoy-Sancaktepe metro lines. The geology is complex consisting of sandstone, arcosic sandstone mudstone, siltstone, shale, limestone, andesite, and quartzitic conglomerate. The geologic units are frequently cut by andesite dykes having significantly fractured contact zones. Two EPB-TBMs having diameters of 6.57m are being used for the lines where the prediction model was tested. Daily advance rates are predicted before starting the project and the results are tested first between shafts 8 and 7 and thereafter the completion of the excavation of the total length of 6250m between the shafts 8 to 2. The results are also validated for a very recent Mecdiyekoy-Mahmutbey Metro Project for hard rock, sity clay and sand. It is believed that the concept behind the proposed methodology will serve a sound basis for decision making for similar projects having complex geology.

Railway transport in Qatar

The article presents the railway infrastructure projects carried out currently in Qatar with special attention to the Doha Metro Project. Types of used structures, such as viaducts and tunnels with a closer look at the construction of trackbed are described in more detail. The last past of the article contains key information about the Tram Network project in Lusail and the Long Distance Lines for the passenger and freight trains.

Performance evaluation of project management implementation based on PMBOK-2008 standard (case study: Ahvaz Metro project)

Performance evaluation of project management implementation based on PMBOK-2008 standard (case study: Ahvaz Metro project)

Application of BIM in the Full Cycle Metro Project

Accidents and damages might occur due to extension of constructing time, complicated procedure and operations, and harsh circumstances brought by the traditional risk management. BIM (Building Information Modeling) appears as an integrated digital management tool, which is featured by being able to visualize, cooperate, simulate and optimize. It is a digital storage of real world building, from which the staffs, including design, building, and operation, could get the information at any time, such as graph, materials statistics, and building progressing. In this research, a full cycle of metro management, including planning, design, collision test, statistics of volume of projects, simulation of building progression, simulation of construction structure, cooperation on spot, was applied to take into consideration cause and effects that might happen in a project. Considering the main potential risks in planning period, construction period and operation period, this paper achieves analysis of capability and efficient management during various periods, via applying 3D visualizing, structure collision test, 4D model constructing, and PW information-shared platform constructing.