Review of vibration-based damage detection and condition assessment of bridge structures using structural health monitoring

As a part of vital infrastructure and transportation networks, bridge structures must function safely at all times. However, due to heavier and faster moving vehicular loads and function adjustment, such as Busway accommodation, many bridges are now operating at an overload beyond their design capacity. Additionally, the huge renovation and replacement costs always make the infrastructure owners difficult to undertake. Structural health monitoring (SHM) is set to assess condition and foresee probable failures of designated bridge(s), so as to monitor the structural health of the bridges. The SHM systems proposed recently are incorporated with Vibration-Based Damage Detection (VBDD) techniques, Statistical Methods and Signal processing techniques and have been regarded as efficient and economical ways to solve the problem. The recent development in damage detection and condition assessment techniques based on VBDD and statistical methods are reviewed. The VBDD methods based on changes in natural frequencies, curvature/strain modes, modal strain energy (MSE) dynamic flexibility, artificial neural networks (ANN) before and after damage and other signal processing methods like Wavelet techniques and empirical mode decomposition (EMD) / Hilbert spectrum methods are discussed here.

Damage assessment in multiple-girder composite bridge using vibration characteristics

This paper uses dynamic computer simulation techniques to apply a procedure using vibration-based methods for damage assessment in multiple-girder composite bridge. In addition to changes in natural frequencies, this multi-criteria procedure incorporates two methods, namely the modal flexibility and the modal strain energy method. Using the numerically simulated modal data obtained through finite element analysis software, algorithms based on modal flexibility and modal strain energy change before and after damage are obtained and used as the indices for the assessment of structural health state. The feasibility and capability of the approach is demonstrated through numerical studies of proposed structure with six damage scenarios. It is concluded that the modal strain energy method is competent for application on multiple-girder composite bridge, as evidenced through the example treated in this paper.

Whole of life cycle cost analysis in bridge rehabilitation

The report presents a methodology for whole of life cycle cost analysis of alternative treatment options for bridge structures, which require rehabilitation. The methodology has been developed after a review of current methods and establishing that a life cycle analysis based on a probabilistic risk approach has many advantages including the essential ability to consider variability of input parameters. The input parameters for the analysis are identified as initial cost, maintenance, monitoring and repair cost, user cost and failure cost. The methodology utilizes the advanced simulation technique of Monte Carlo simulation to combine a number of probability distributions to establish the distribution of whole of life cycle cost. In performing the simulation, the need for a powerful software package, which would work with spreadsheet program, has been identified. After exploring several products on the market, @RISK software has been selected for the simulation. In conclusion, the report presents a typical decision making scenario considering two alternative treatment options.

User friendly guide for rehabilitation or strengthening of bridge structures using fiber reinforced polymer composites

A worldwide interest is being generated in the use of fibre reinforced polymer composites (FRP) in rehabilitation of reinforced concrete structures. As a replacement for the traditional steel plates or external post-tensioning in strengthening applications, various types of FRP plates, with their high strength to weight ratio and good resistance to corrosion, represent a class of ideal material in external retrofitting. Within the last ten years, many design guidelines have been published to provide guidance for the selection, design and installation of FRP systems for external strengthening of concrete structures. Use of these guidelines requires understanding of a number of issues pertaining to different properties and structural failure modes specific to these materials. A research initiative funded by the CRC for Construction Innovation was undertaken (primarily at RMIT) to develop a decision support tool and a user friendly guide for use of fibre reinforced polymer composites in rehabilitation of concrete structures. The user guidelines presented in this report were developed after industry consultation and a comprehensive review of the state of the art technology. The scope of the guide was mainly developed based on outcomes of two workshops with Queensland Department of Main Roads (QDMR). The document covers material properties, recommended construction requirements, design philosophy, flexural, shear and torsional strengthening of beams and strengthening of columns. In developing this document, the guidelines published on FIB Bulletin 14 (2002), Task group 9.3, International Federation of Structural Concrete (FIB) and American Concrete Institute Committee 440 report (2002) were consulted in conjunction with provisions of the Austroads Bridge design code (1992) and Australian Concrete Structures code AS3600 (2002). In conclusion, the user guide presents design examples covering typical strengthening scenarios.

Trip to Sunshine Coast Queensland, September 2004 visit to bridge and foreshore

A trip was undertaken to look at concerns of Public Works and Main Roads Departments of Queensland. David Paterson and Wayne Ganther from CSIRO travelled to the Sunshine Coast with Alan Carse of Queensland Department of Main Roads and Michael Ball of Queensland Department of Public Works. We were also joined for part of the visits by Ed Bowers of QBuild which is a commercial unit of Public Works responsible for maintenance of Public Works. During the trip we visited a bridge on the David Low Way at Sunrise Beach near Noosa. This bridge was in a serve marine environment with high salt content in the concrete and corrosion of the galvanised guardrails and barriers. Also the foreshore at Coolum was visited and the use of stainless steel was examined. This is discussed in this report. Most problems stemmed from incorrect specification due to lack of awareness of the severity of the environment. The companion report Visit to Schools Report 2002-059-B No 7. covers the visit to four schools north of Caloundra.

Entrepreneurship and family firms : a case study in growth and survival

Entrepreneurial marketing has gained popularity in both the entrepreneurship and marketing disciplines in recent times. The success of ventures that have pursued what are considered non-traditional marketing approaches has been attributed to entrepreneurial marketing practices. Despite the multitude of marketing concepts and models, there are prominent venture successes that do not conform to these and have thus been put in the ''entrepreneurial'' box. One only has to look to the ''Virgin'' model to put this in context. Branson has proven for example that not ''sticking to the knitting'' can work with the ways the Virgin portfolio has been diversified. Consequently, an entrepreneurial orientation is considered a desirable philosophy and has become prominent in such industries as airlines and information technology. Miles and Arnold (1991) found that entrepreneurial orientation is positively correlated to marketing orientation. They propose that entrepreneurial orientation is a strategic response by firms to turbulence in the environment. While many marketing successes are analysed in hindsight using traditional marketing concepts and strategies, there are those that challenge standard marketing textbook recommendations. Marketing strategy is often viewed as a process of targeting, segmenting and positioning (STP). Academics and consultants advocate this approach along with the marketing and business plans. The reality however is that a number of businesses do not practice these and pursue alternative approaches. Other schools of thought and business models have been developing to explain differences in orientation such as branding (Keller 2001), the service-dominant logic (Vargo and Lusch 2004) and effectuation logic (Sarasvathy 2001). This indicates that scholars are now looking to cognate fields to explain a given phenomenon beyond their own disciplines. Bucking this trend is a growing number of researchers working at the interface between entrepreneurship and marketing. There is now an emerging body of work dedicated to this interface, hence the development of entrepreneurial marketing as an alternative to the traditional approaches. Hills and Hultman (2008:3) define entrepreneurial marketing as ''a spirit, an orientation as well as a process of passionately pursuing opportunities and launching and growing ventures that create perceived customer value through relationships by employing innovativeness, creativity, selling, market immersion, networking and flexibility.'' Although it started as a special interest group, entrepreneurial marketing is now gaining recognition in mainstream entrepreneurship and marketing literature. For example new marketing textbooks now incorporate an entrepreneurial marketing focus (Grewal and Levy 2008). The purpose of this paper is to explore what entrepreneurial approaches are used by entrepreneurs and their impact on the success of marketing activities. Methodology/Key Propositions In order to investigate this, we employ two cases: 42Below, vodka producers from New Zealand and Penderyn Distillery, whisky distillers from Wales. The cases were chosen based on the following criteria. Firstly, both companies originate from small economies. Secondly, both make products (spirits) from locations that are not traditionally regarded as producers of their flagship products and thirdly, the two companies are different from each other in terms of their age. Penderyn is an old company established in 1882, whereas 42Below was founded only in 1999. Vodka has never been associated with New Zealand. By the same token, whisky has always been associated with Scotland and Ireland but never been with Wales. Both companies defied traditional stereotypes in marketing their flagship products and found international success. Using a comparative a case study approach, we use Covin and Slevin's (1989) set of items that purport to measure entrepreneurial orientation and apply a qualitative lens on the approaches of both companies. These are: 1. cultural emphases on innovation and R&D 2. high rate of new product introduction 3. bold, innovative product development 4. initiator proactive posture 5. first to introduce new technologies and products 6. competitive posture toward competitor 7. strong prolictivity for high risk, high return projects 8. environment requires boldness to achieve objectives 9. when faced with risk, adopts aggressive, bold posture. Results and Implications We find that both companies have employed entrepreneurial marketing approaches but with different intensities. While acknowledging that they are different from the norm, the specifics of their individual approaches are dissimilar. Both companies have positioned their products at the premium end of their product categories and have emphasised quality and awards in their communication strategies. 42Below has carved an image of irreverence and being non-conformist. They have unashamedly utilised viral marketing and entered international markets by training bartenders and hosting unconventional events. They use edgy language such as vodka university, vodka professors and vodka ambassadors. Penderyn Distillery has taken a more traditional approach to marketing its products and portraying romantic images of age-old tradition of distilling as key to their positioning. Both companies enjoy success as evidenced by industry awards and international acclaim.

Effect of height of bridge above water on salt deposition levels

Maintenance of bridge structures is a major issue for the Queensland Department of Main Roads. In the previous phase of this CRC project an initial approach was made towards the development of a program for lifetime prediction of metallic bridge components. This involved the analysis of five representative bridge structures with respect to salt deposition (a major contributor to metallic corrosion) to determine common elements to be used as “cases” - those defined for buildings are not applicable. The five bridges analysed included the Gladstone Port Access Road Overpass, Stewart Road Overpass, South Johnstone River Bridge, Johnson Creek Bridge and the Ward River Bridge.

Strategies for minimising the whole of life cycle cost of reinforced concrete bridge exposed to aggressive environments

n design of bridge structures, it is common to adopt a 100 year design life. However, analysis of a number of case study bridges in Australia has indicated that the actual design life can be significantly reduced due to premature deterioration resulting from exposure to aggressive environments. A closer analysis of the cost of rehabilitation of these structures has raised some interesting questions. What would be the real service life of a bridge exposed to certain aggressive environments? What is the strategy of conducting bridge rehabilitation? And what are the life cycle costs associated with rehabilitation? A research project funded by the CRC for Construction Innovation in Australia is aimed at addressing these issues. This paper presents a concept map for assisting decision makers to appropriately choose the best treatment for bridge rehabilitation affected by premature deterioration through exposure to aggressive environments in Australia. The decision analysis is referred to a whole of life cycle cost analysis by considering appropriate elements of bridge rehabilitation costs. In addition, the results of bridges inspections in Queensland are presented

The legality of tissue transplants for the benefit of family members in the UK and Australia : implications for saviour siblings

The ethics of creating ‘saviour siblings’ for the benefit of another has received much attention, but little consideration has been given to the legal position of those saviours born who may be asked to provide tissue for transplantation to another during childhood. This article examines the ethical issues surrounding minor donation as well as the existing legal framework in the UK and Australia that regulates minors providing tissue for the benefit of another. Against this background the position of minor saviours, who are called upon to donate bone marrow or peripheral blood stem cells, is examined. This analysis suggests that the law does not provide sufficient protection for minor saviours who are called upon to donate to another. It is argued that specific ethical obligations are owed to saviours—that ought to be reflected in the law—in order to protect them from exploitation while they remain minors.

A45 ICT curriculum design to bridge the gap between industry and academia

Building Information Model (BIM) software, collaboration platforms and 5D Construction Management software is now commercially available and presents the opportunity for construction project teams to design more cost effectively, plan construction earlier, manage costs throughout the life cycle of a building project and provide a central asset management register for facilities managers. This paper outlines the merits of taking a holistic view of ICT in curriculum design. The educational barriers to implementation of these models and planning tools are highlighted. Careful choice of computer software can make a significant difference to how quickly students can master skills; how easy it is to study and how much they enjoy learning and be prepared for employment. An argument for BIM and 5D planning tools to be introduced into the curriculum to assist industry increase productivity and efficiencies are outlined by the authors.

Decision support in using fibre reinforced polymer (FRP) composites in rehabilitation of concrete bridge structures

This paper compares and reviews the recommendations and contents of the guide for the design and construction of externally bonded FRP systems for strengthening concrete structures reported by ACI committee 440 and technical report of Externally bonded FRP reinforcement for RC structures (FIB 14) in application of carbon fiber reinforced polymer (CFRP) composites in strengthening of an aging reinforced concrete headstock. The paper also discusses the background, limitations, strengthening for flexure and shear, and other related issues in use of FRP for strengthening of a typical reinforced concrete headstock structure such as durability, de-bonding, strengthening limits, fire and environmental conditions. A case study of strengthening of a bridge headstock using FRP composites is presented as a worked example in order to illustrate and compare the differences between these two design guidelines when used in conjunction with the philosophy of the Austroads (1992) bridge design code.

Comparison between ACI 440 and FIB 14 design guidelines in using CFRP for strengthening of a concrete bridge headstock

This paper compares and reviews the recommendations and contents of the guide for the design and construction of externally bonded FRP systems for strengthening concrete structures reported by ACI committee 440 and technical report of Externally bonded FRP reinforcement for RC structures (FIB 14) in application of carbon fiber reinforced polymer (CFRP) composites in strengthening of an aging reinforced concrete headstock. The paper also discusses the background, limitations, strengthening for flexure and shear, and other related issues in use of FRP for strengthening of a typical reinforced concrete headstock structure such as durability, de-bonding, strengthening limits, fire and environmental conditions. A case study of strengthening of a bridge headstock using FRP composites is presented as a worked example in order to illustrate and compare the differences between these two design guidelines when used in conjunction with the philosophy of the Austroads (1992) bridge design code.