Making sense of bridge monitoring: Vision for the future

PublishedThis paper presents a vision for the future monitoring systems which will become normal requirements for management of bridges as key objects of national infrastructure in the UK and elsewhere. Rather than being pushed by authorities and legislation, we expect that bridge managers will recognize the clear business cases for investing in well-designed targeted monitoring. To support this proposition, the paper presents two case studied where state-of-the-art bridge monitoring technology was used or potentially could be used to: • Decide when to inspect and change bridge bearings, and • Decide when to close various traffic lanes to reduce probability of overstressing bridge structural components. © 2013 Taylor & Francis Group

Human factors simulation for motion and serviceability in the built environment

This is the author accepted manuscriptEngineering and Physical Sciences Research Council (EPSRC

Company failure in the construction industry: a critical review and a future research agenda

TS 1M – Project and Organisation Management I: Paper no. 4360Company failure is not only extremely disruptive to an industry but may also cause significant rippling effects in an economy. Construction companies are vulnerable to bankruptcy due to the fragmented nature of the industry, high competition, the high uncertainty and risk involved, and considerable fluctuations in construction volume. It is important to recognize any potential company failures at the earliest opportunity. While bankruptcy prediction has long been regarded as a critical topic in the accounting and finance sectors, this research topic is still under-explored in the context of the construction industry. This paper aims to provide a synthesis of the previous business failure prediction models for construction companies and put forward a future agenda in this research area. Common causes of construction company failures are also reviewed. Using the results from the proposed research, it is anticipated that construction companies will be better able to prevent business failure and this should be relevant to the current needs of the construction industry and significant to the society.postprintThe 24th FIG International Congress: Facing the Challenges – Building the Capacity, Sydney, Australia, 11-16 April 2010

Asymptotic identification uncertainty of close modes in Bayesian operational modal analysis

This is the final version. Available on open access from Elsevier via the DOI in this recordClose modes are not typical subjects in operational modal analysis (OMA) but they do occur in structures with modes of similar dynamic properties such as tall buildings and towers. Compared to well-separated modes they are much more challenging to identify and results can have significantly higher uncertainty especially in the mode shapes. There are algorithms for identification (ID) and uncertainty calculation but the value itself does not offer any insight on ID uncertainty, which is necessary for its management in ambient test planning. Following a Bayesian approach, this work investigates analytically the ID uncertainty of close modes under asymptotic conditions of long data and high signal-to-noise ratio, which are nevertheless typical in applications. Asymptotic expressions for the Fisher Information Matrix (FIM), whose inverse gives the asymptotic ‘posterior’ (i.e., given data) covariance matrix of modal parameters, are derived explicitly in terms of governing dynamic properties. By investigating analytically the eigenvalue properties of FIM, we show that mode shape uncertainty occurs in two characteristic types of mutually uncorrelated principal directions, one perpendicular (Type 1) and one within the ‘mode shape subspace’ spanned by the mode shapes (Type 2). Uncertainty of Type 1 was found previously in well-separated modes. It is uncorrelated from other modal parameters (e.g., frequency and damping), diminishes with increased data quality and is negligible in applications. Uncertainty of Type 2 is a new discovery unique to close modes. It is potentially correlated with all modal parameters and does not vanish even for noiseless data. It reveals the intrinsic complexity and governs the achievable precision limit of OMA with close modes. Theoretical findings are verified numerically and applied with field data. This work has not reached the ultimate goal of ‘uncertainty law’, i.e., explicitly relating ID uncertainty to test configuration for understanding and test planning, but the analytical expressions of FIM and understanding about its eigenvalue properties shed light on possibility and provide the pathway to it.Engineering and Physical Sciences Research Council (EPSRC

Reducing embodied carbon of construction facilities through product-based carbon labelling scheme

link_to_subscribed_fulltex

Vision-Based Bridge Deformation Monitoring

This is the final version of the article. Available from Frontiers Media via the DOI in this record.Optics-based tracking of civil structures is not new, due to historical application in surveying, but automated applications capable of tracking at rates that capture dynamic effects are now a hot research topic in structural health monitoring. Recent innovations show promise of true non-contacting monitoring capability avoiding the need for physically attached sensor arrays. The paper reviews recent experience using the Imetrum Dynamic Monitoring Station (DMS) commercial optics-based tracking system on Humber Bridge and Tamar Bridge, aiming to show both the potential and limitations. In particular, the paper focuses on the challenges to field application of such a system resulting from camera instability, nature of the target (artificial or structural feature), and illumination. The paper ends with evaluation of a non-proprietary system using a consumer-grade camera for cable vibration monitoring to emphasize the potential for lower cost systems where if performance specifications can be relaxed.The GPS system at Humber was created by Dr. Ki Koo with support from EPSRC grant EP/F035403/1. DH was supported via the Marie Curie Fellowship programme and as such the research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 330195

Enhancing public engagement in a fast-paced project environment

published_or_final_versio

A structural equation model of feasibility evaluation and project success for publicprivate partnerships in Hong Kong

A successful publicprivate partnership (PPP) scheme can be described as one that can lead to the delivery of high-quality end products and/or services, which can satisfy the needs of the community, achieve the intended targets/goals of the government, as well as provide a favorable financial return for the private sector involved with the project. This study aims to establish an evaluation framework for the initial feasibility evaluation of a PPP project that would satisfy all the stakeholders. The factors for evaluating the feasibility of PPP projects can be classified into five broad categories: technical; financial and economic; social; political and legal; and others. Through the structural equation modeling approach, data attained from a questionnaire survey conducted in Hong Kong was analyzed and a model was developed to examine the relationships between different evaluation factors and the overall satisfaction of stakeholders. The results indicate that technical and social aspects are critical to the feasibility of PPP projects, and therefore, are the determining factors for success. This paper should assist relevant stakeholders to improve their understanding on the relative importance of the evaluation factors, and help to establish a comprehensive framework for decision makers to evaluate the feasibility of PPP projects. The predictors for PPP project success were also determined to enrich the knowledge base and help formulate management strategies to better implement the PPP project delivery approach. © 2010 IEEE.published_or_final_versio

Vibration serviceability of Helix Bridge, Singapore

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record. Published Online: May 18, 2016The Helix Bridge is a key feature of the iconic Marina Bay Sands development in Singapore. It usually functions as a pedestrian link between the Esplanade and Sands Casino/Hotel, but is occasionally used as a viewing platform for events in Marina Bay that have centred on a small purpose built stadium opposite the bridge. To supplement the stadium capacity, a number of integral cantilevered 'pods' have been built into Helix Bridge. Because of its dual role Land Transport Authority, Singapore commissioned a vibration serviceability evaluation of the bridge following a specification developed by Arup Australia. The vibration serviceability evaluation was carried out in three stages. First, an experimental campaign comprising multi-shaker modal testing was used to estimate modal properties. Next, limited pedestrian and crowd testing directly evaluated the dynamic response to individuals and small groups walking, running or jumping. Finally, modal properties were utilised, with bespoke simulation software, to predict the performance of the bridge under extreme crowd loading, using models specified in the most up-to-date design guidance on crowd loading for pedestrian bridges and stadia. The bridge performance proved to be acceptable, both in the direct testing with small groups and the simulations of large crowds

Rethinking public participation in infrastructure projects

The mission of any public infrastructure and construction (PIC) projects is to improve the well-being of the society. In spite of this, as some of these projects might impact on the environment and affect the habitat of local residents, it is not unusual to attract criticism or even opposition from various stakeholder groups. Consequently, there is an increasing concern about the effectiveness of public participation for PIC projects. The authors strive to examine the salient elements of public participation by considering the questions of 'who', 'what' and 'how' in the process. The paper begins by reviewing the international public participation practices and the models proposed by various researchers. The key aspects to be considered during the public participation process are then highlighted. The paper concludes by proposing a comprehensive participatory framework for PIC projects, especially those of a highly sensitive nature. The results show that the standpoints of various stakeholders can be rather diverse and it is necessary to ensure a consensus is reached at different project stages through a well-planned, whole-cycle participatory exercise in order to maximise the chance of project success. More importantly, better acceptance towards other views and more education on the importance of public participation are needed to ensure that society benefits from economic and social development without sacrificing the rights and best interests of the minority groups.published_or_final_versio