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Underground parking projects are expensive. The capital cost of underground parking projects has been, and still is, one of the promoter’s main economic concerns. Therefore, the capital cost estimation is an essential task in the early stages of underground parking projects. In this context, the promoters mainly use cost estimation models, most of them produced by methodologies with lack of precision and with low performances. Over the last years Portugal has embarked on a large programme of underground parking projects in the major cities. The present research work is based on data and knowledge colleted from that programme. This paper presents an analysis of the underground parking projects built and underway in Portugal. It discusses the main variables influencing the capital cost of under‐ground parking projects. Finally, it presents a mathematical model for estimating capital cost of this type of project during the planning phase.

Infrastructure projects play a vital role in the development of countries' economies. However, these projects, notably underground ones, are encountering growing claims as they are subject to many unknowns. Without having a clear insight into the causes of claims and their influence on one another, it is not possible to mitigate their adverse impacts on these projects' goals. To this aim, the main purpose of this study is to identify the critical paths leading to cost claims for underground metro projects.

First, causes of claims were identified through a literature review and then refined to 22 main causes according to the opinions of 148 Iranian experts. A qualitative system dynamics (SD) model was then provided to visualize how various causes interact with each other. The model was developed and validated by drawing on the expertise of industry-related experts, and the critical paths were finally recognized based on their frequency and severity indexes.

The findings revealed that each cause should be evaluated based on their connections with others as there are complex relations among the causes. It was also shown that the major claim paths among others were initiated due to ambiguous contract clauses, unforeseen physical conditions and land handover problems.

The findings of this study provide a better insight into how various causes of claims for underground metro projects are related to each other and can eventually assist project managers of different parties, even in other countries, to select proportional strategies to mitigate their adverse impacts.

The article begins by analysing the reasons why many projects flounder. A key feature is seen to be the inability of any single manager to keep track of all the activities involved. Computerised project management systems are now relational database management systems: their increasing sophistication and use are described.

The image of the construction industry in China, as in many other countries, is tarnished by its poor safety record. With the rapid development of subway systems in Chinese urban areas, construction workers are being exposed to new risks which are poorly understood and managed. Subway construction projects are large scale and scattered over many construction sites, and involve numerous stakeholders and sophisticated technologies in challenging underground environments. Accident rates are high and have significant economic and social consequences for the firms and people involved. Addressing the gap in research about the safety risk in these projects, the purpose of this paper is to advance understanding of the factors influencing the safety of Chinese subway construction projects with the overall objective of reducing accident rates.

A survey was conducted with 399 subway construction professionals across five stakeholder groups. Follow-up interviews were also conducted with five experienced experts in safety management on subway projects to validate the results.

It was found that the eight most critical factors perceived by stakeholders to influence safety risks on Chinese subway projects are: project management team; contractor-related factors; site underground environment; safety protection during the use of machines; safety management investment; site construction monitoring and measurement; hazard identification and communication; and use of machines in all stages. This indicates that in allocating limited project resources to improve the safety of subway projects, managers should focus on: developing safety knowledge and positive attitudes in leadership teams; formulating effective risk management systems to identify, assess, mitigate, measure and monitor safety risks on site; improving communications with stakeholders about these risks and effectively managing plant, equipment and machinery.

This research contributes a new multi-stakeholder perspective to the lack of safety research in Chinese subway construction projects. The research findings provide important new insights for policymakers and managers in improving safety outcomes on these major projects, producing potentially significant social and economic benefits for society and the construction industry.

The purpose of this paper is to show how the time frame for the execution of a construction project in Algeria is rarely respected because of organizational problems and uncertainties encountered while the execution is underway.

A case study on the construction of a metro station is used as a pilot project to show the effectiveness of replacing traditional construction processes by more innovative procedures. Concurrent engineering (CE) is applied to optimize the execution time of the underground structure. A numerical simulation is integrated into the construction process in order to update design parameters with real site conditions observed during the construction process.

The results show that the implementation of CE is efficient in reducing the completion time, with an 18 per cent reduction observed in this case study. A cost reduction of 20 per cent on the steel frame support and a total cost reduction of 3 per cent were obtained.

The study demonstrates that the application of CE methods can be quite valuable in large, complex construction projects. Vulgarizing it as “the solution” to adjust time frame delay, control quality and cost, might be an issue for local construction enterprises in Algeria.

Using the concept of CE by overlapping different activities involved in a construction project and making use of simulation tools in the process at different stages of the execution have resulted in modifying the excavation method and hence reducing the completion times.

Due to land resource scarcity, sustainable urban development in high-density cities has long been challenging. As such, many cities are formulating plans to “dig deep”, resulting in more citizens working and/or staying underground for longer periods of time. However, owing to the particularities of underground space, the factors involved in the creation of a healthy environment are different from those involved in aboveground developments. This study thus aims to investigate the influences of various underground environment factors on users' health through a holistic approach.

To achieve this aim, 12 underground sites and 12 corresponding aboveground sites are selected for a large-scale questionnaire survey, resulting in 651 survey samples. The survey covers post-occupancy evaluation of health (physical and psychosocial), underground environmental quality (visual, thermal, acoustic comfort, indoor air quality and ventilation), space design and greenery. Independent-sample T-test, Pearson correlation, multiple regression modelling and structural equation modelling are used to investigate whether significant differences exist between health of underground and aboveground users, and to develop an underground environment-health model for unveiling the significant associations between underground environment factors and users' health. To cross validate the results, an objective field measurement study is further conducted on six underground sites. The objective measurement results are used to cross validate the survey results.

The questionnaire results provide the following evidence: (1) health of underground users is significantly poorer than that of their aboveground counterparts; (2) underground development users' health is significantly affected by space design, greenery and environmental quality in terms of thermal comfort, indoor air quality, ventilation and acoustic comfort but not visual comfort; and (3) amongst the various identified factors, space design has the strongest predicting effects on human health. The field study echoes the survey findings and further unveils the relationships between different environmental factors and human health.

The results shed light on the importance of distinguishing between underground developments and aboveground ones in various guidelines and standards, especially those related to space management.

The purpose of this paper is to propose a new method to achieve omni-directional vibration vector signal acquisition, and use this method to improve the accuracy of the underground explosion point localization.

Following an introduction, this paper describes the design principle of a sensor structure, and discusses the rationality of the spherical structure of the sensor through finite element analysis. The sensor prototype is designed according to the above method, and its performance is tested by the sensor calibration experiment. Finally, applications are also discussed.

This paper shows that the method for underground omni-directional vibration signal acquisition is reasonable and feasible. The vibration sensor, designed by this method, of which the triaxial dynamic characteristics are consistent, and the three-dimensional vibration information acquired by this sensor can achieve high-precision localization for an underground explosion point.

The paper describes a new method for omni-directional vibration vector signal acquisition. The vibration sensor is developed based on this method, which has a broad application prospect in the positioning of an underground explosion point, the evaluation of explosive power and other underground projects.

The purpose of this paper is to empirically compare the risk factors in public-private partnership (PPP) projects in developing and developed countries, represented by Ghana and Hong Kong, respectively.

A structured questionnaire survey was conducted with PPP practitioners in Ghana and Hong Kong. In total, 103 valid responses were received for analysis. Kendall’s coefficient of concordance and mean ranking were used for data analysis.

The results show that respondents from Ghana ranked country risk factors higher, whereas their Hong Kong counterparts ranked project-specific risks higher. The top five significant risks in Ghana are corruption, inflation rate fluctuation, exchange rate fluctuation, delay in project completion and interest rate fluctuation. In Hong Kong, the top five significant risk factors are delay in land acquisition, operational cost overruns, construction cost overruns, delay in project completion and political interference.

The results of the study inform international investors of the appropriate risk mitigation measures and preventive actions to use when engaging in PPP arrangements in any part of the world. Further, governments who are yet to use the PPP concept would be informed of the prevailing risk factors in other neighbouring countries (i.e. developing or developed countries).

This study collected the bibliographic data of 2034 journal articles published in 2000–2021 from Web of Science (WoS) core collection database and adopted two bibliometric analysis methods, namely historiography and keyword co-occurrence, to identify the evolution trend of construction risk management (CRM) research topics.

CRM has been a key issue in construction management research, producing a big number of publications. This study aims to undertake a review of the global CRM research published from 2000 to 2021 and identify the evolution of the research topics relating to CRM.

This study found that risk analysis methods have shifted from simply ranking risks in terms of their relative importance or significance toward examining the interrelationships among risks, and that the objects of CRM research have shifted from generic construction projects toward specified types of construction projects (e.g. small projects, underground construction projects, green buildings and prefabricated projects). In addition, researchers tend to pay more attention to an individual risk category (e.g. political risk, safety risk and social risk) and integrate CRM into cost, time, quality, safety and environment management functions with the increasing adoption of various information and communication technologies.

This study focused on the journal articles in English in WoS core collection database only, thus excluding the publications in other languages, not indexed by WoS and conference proceedings. In addition, the historiography focused on the top documents in terms of document strength and thus ignored the role of the documents whose strengths were a little lower than the threshold.

This review study is more inclusive than any prior reviews on CRM and overcomes the drawbacks of mere reliance on either bibliometric analysis results or subjective opinions. Revealing the evolution process of the CRM knowledge domain, this study provides an in-depth understanding of the CRM research and benefits industry practitioners and researchers.