Showing papers in "Civil Engineering and Environmental Systems in 2015"

Come back sociotechnical systems theory, all is forgiven...

Abstract: Why, despite all the effort and expense, do engineering systems sometimes show an abject lack of resilience, with the smallest of human failures being the difference between normality and a calamitous disaster? If people made the kind of rational choices tacitly designed into our Civil Engineering endeavours, then a fair slice of humanity's grand challenges would probably disappear. Sociotechnical systems (STS) theory was an approach developed to address these matters. Several large firms embraced the principles to give rise to organisations that were highly adaptable, flexible, responsive, and above all resilient. What we have in STS theory is a powerful demonstration of how to harness the emergent edge-of-chaos properties of humans, jointly optimised with engineering, which could offer a radical new approach to resilience.

An efficient method for structural damage detection using a differential evolution algorithm-based optimisation approach

Abstract: An efficient method employing the differential evolution algorithm (DEA) as an optimisation solver is presented here to identify the multiple damage cases of structural systems. Natural frequency changes of a structure are considered as a criterion for damage occurrence. The structural damage detection problem is first transformed into a standard optimisation problem dealing with continuous variables, and then the DEA is utilised to solve the optimisation problem for finding the site and extent of structural damage. In order to assess the performance of the proposed method for structural damage identification, some illustrative examples are numerically tested, considering also measurement noise. All the numerical results demonstrate the effectiveness of the proposed method for accurately determining the site and extent of multiple-structural damage. Also, the performance of the DEA for damage detection compared to the standard particle swarm optimisation is confirmed by a test example.

Resilience in disaster research: three versions

Abstract: This paper explores the concept of resilience in disaster management settings in modern society. The diversity and relatedness of ‘resilience’ as a concept and as a process are reflected in its presentation through three ‘versions’: (i) pastoral care and the role of the church for victims of disaster trauma, (ii) federal policy and the US Critical Infrastructure Plan, and (iii) the building of resilient communities for disaster risk reduction practices. The three versions aim to offer characteristic expressions of resilience, as increasingly evident in current disaster literature. In presenting resilience through the lens of these three versions, the article highlights the complexity in using resilience as an all-encompassing word. The article also suggests the need for understanding the nexuses between risk, vulnerability, and policy for the future of resilience discourse.

‘Resilience thinking’ in transport planning

Abstract: Resilience has been discussed in ecology for over 40 years. While some aspects of resilience have received attention in transport planning, there is no unified definition of resilience in transportation. To define resilience in transportation, I trace back to the origin of resilience in ecology with a view of revealing the essence of resilience thinking and its relevance to transport planning. Based on the fundamental concepts of engineering resilience and ecological resilience, I define ‘comprehensive resilience in transportation’ as the quality that leads to recovery, reliability and sustainability. Observing that previous work in resilience analysis in transportation has focussed on addressing engineering resilience rather than ecological resilience, I conclude that transformability has been generally overlooked and needs to be incorporated in the analysis framework for comprehensive resilience in transportation.

Linking disaster resilience and sustainability

Abstract: Resilience and sustainability have both gained traction in civil engineering. There is significant overlap between both fields, but practitioners tend to remain confined to their niche. This paper clarifies the link between both fields, reflects on the underlying concepts, and identifies challenges and opportunities in understanding complex problems involving both resilience and sustainability. A conceptual framework is proposed for understanding resilience and sustainability together. The example of a coastal town subject to sea-level rise and large storms is used to motivate the framework. The example is used to evaluate the use of discount rates for events in the distant future. The results are discussed to determine our ability to decide whether such scenarios are sustainable. The conclusion is that computational approaches will be inadequate. Rather, there is a need for qualitative thinking that embraces ambiguity and unmeasurable uncertainty.

Integrating disciplinary contributions to achieve community resilience to natural disasters

Abstract: Community resilience to natural disasters is a complex social problem that can benefit greatly from truly interdisciplinary research (IDR). While funders and universities frequently endorse interdisciplinarity, much of what actually happens can best be described as multidisciplinary, that is, parallel and additive rather than integrated and synergistic. Moving beyond that is harder than it might initially seem. Doing so requires understanding both the benefits of and barriers to its successful implementation. Benefits include better addressing questions at disciplinary intersections; providing more cohesive, useful recommendations to practitioners; improving assumptions in disciplinary studies based on input from other disciplines; and facilitating idea sharing across analogous parts of the problem, such as different hazards. Barriers include institutional systems that discourage researchers from engaging in IDR, and disciplinary differences that make it difficult to do. The paper concludes with thoughts ...

Reinforcing relationships for resilience – by embedding end-user ‘people’ in public–private partnerships

Abstract: Public–private partnerships (PPPs) target overall benefits from mobilising private resources in delivering public infrastructure. Their longer time spans generate higher risks, hence the greater need for resilience in PPPs, compared to traditional procurement. PPP infrastructure outcomes should include both sustainable and resilient built infrastructure, as well as reliable and resilient service delivery. The public–private cross-sectoral relationships can be significant contributors to resilience. Previous research findings show that public–private relationships are still predominantly formal in PPPs. However, appropriate informal relationships can foster mutual trust and better teamworking that trigger self-adjustment mechanisms to overcome adversities and enhance resilience. Integrating relevant ‘people’ into PPPs to establish a public–private–people partnership (4P) is proposed to reinforce formal–informal relationships, while enhancing relevant ‘social infrastructure’, which could then lead to more r...

Constructed wetlands for stormwater management in the UK: a concise review

Abstract: The use of constructed wetlands (CWs) for stormwater management is growing due to the need for sustainable water use and to prevent damage to local watercourses caused by the pollutants collected and transported by runoff. However, despite their increased use around the world, there is a lack of information regarding the use of CWs for stormwater management in the UK. This study reviews the application of CW systems for stormwater management in the UK by examining the design, treatment performance and challenges associated with their use, while drawing comparisons with the rest of the world. The review indicates that although CWs have the potential for cost-effective and efficient stormwater management in the UK, there are several challenges that must be overcome to allow their widespread implementation. These include (i) a lack of design codes and unified guidelines; (ii) ambiguities regarding drainage responsibilities and land use issues and (iii) land availability.

A hierarchy of measures for infrastructure resilience – learning from post-disaster reconstruction in Christchurch, New Zealand

Abstract: Recent research into the concept of resilience has shown that it helps key players in urban development to assess and set priorities for resistance and recovery for disaster risk management. However, a competing issue within post-disaster recovery is managing the trade-offs between quickly restoring infrastructure services versus taking time to consider and consult on alternative options. Through an examination of the post-earthquake reconstruction in Christchurch, New Zealand, this paper considers infrastructure resilience by using a hierarchy of measures. This hierarchy shows how infrastructure resilience needs to be considered as a series of interventions in response to different levels of damage. It elucidates the varying nature of resilience measures, the decision-making processes required to implement them and constraints, chiefly in funding, that prevent wider application of such measures. This is an important consideration for defining and acting upon the opportunity for change created by a disast...

Transitioning to sustainable urban water management systems: how to define expected service functions?

Abstract: Sustainable water management is a worldwide challenge for the twenty-first century. It involves replacing traditional management approaches with a new concept, often referred to as sustainable urban water management (SUWM). This paradigm shift means that SUWM systems must include new services, some of which have already emerged. However, no publications have presented the expected SUWM system in terms of the full range of services it would need to include, and no publications have proposed a method for identifying the services the system must provide. This paper proposes a method for identifying these services and presents a generic petal diagram to represent the service functions of the SUWM system. Moreover, this paper presents a new method for defining these services in a specific territory. This method is based on the confrontation between a general representation and the objectives of the stakeholders in a given system in a given territory. The method is illustrated with a full-scale case study on th...

Improving resilience through vulnerability assessment and management

Abstract: The increasing complexity of infrastructure systems and the possibility of severe consequences due to interdependency and uncertain demands have led to an increased emphasis on resilience. Resilience, in simple terms, is the ability of a system to withstand adverse conditions and to recover quickly from these. Its interpretations and linkages to the related concepts of vulnerability and risk are examined. It is argued that vulnerability is an inherent characteristic of any system, hard or soft, and its identification and management is essential for improving the system's resilience. A systems approach to identify the vulnerable failure scenarios uses the concepts of form, connectivity and hierarchical modelling. Modelling of interactions with social systems and assessing their consequences requires dealing with uncertainty and it remains a challenge.

Improving community resilience to natural events

Abstract: Improving community resilience requires a way of thinking about the nature of a community. Two complementary aspects are proposed: the flows connecting the community with its surrounding environment and the resources the community needs for its ongoing life. The body of necessary resources is complex, with many interactions between its elements. A systems approach is required to understand the issues adequately. Community resilience is discussed in general terms together with strategies for improving it. The ideas are then illustrated and amplified by an extended case study addressing means of improving the resilience of a community on the West Coast of New Zealand to natural disasters. The case study is in two phases. The first relies on a mix of on-the-ground observations and constructed scenarios to provide recommendations for enhancing community resilience, while the second complements the first by developing a set of general lessons and issues to be addressed from observations of the Christchurch ear...

A dynamic sustainability Balanced Scorecard methodology as a navigator for exploring the dynamics and complexity of corporate sustainability strategy

Abstract: The majority of recent empirical research regarding corporate environmental literature seeks to identify the potential relationships between environmental management practices and the financial performance of the firms. In addition, another major part of the research concerns the effect of corporate social responsibility practices on corporate financial performance. The majority of these studies focus on the effect of either social or environmental aspects on firms’ economic performance through various statistical techniques in an ex post and static base (at the end of year – annually). To contribute to this literature, this article aims at developing a dynamic sustainability Balance Scorecard methodology to investigate the evolutionary trends of the relationships among environmental, social, and economic performance of firms. The main contribution is the development of an integrated mental model in order to improve managers’ and scholars’ comprehension of corporate sustainability performance. The propose...

Incorporating resilience through adaptability and flexibility

Abstract: The paper positions adaptable systems as a core concept in resilience. Through a control systems theory framework, it is shown how closed loop control selection leads to system recovery or the return to desired system states following changes in the external environment. The concepts advanced are illustrated on project performance, where system controls are adjusted in response to impacting events, in order to recover the project. The value of having adaptability and flexibility is demonstrated through economic arguments, exampled on a piece of infrastructure subjected to a changing climate.

Network structure, complexity, and adaptation in water resource systems

Abstract: Infrastructure systems are often complex. Many have both natural and built components. For such systems, including water resource networks, resilience is a common policy goal. In the formalised study of complex systems, the structure and function of networks can contribute directly to system resilience. One branch of complex systems studies, network science, describes how connectivity between individual components can explain some system-wide properties of growth and reliability. Water resource systems analysis has only begun to apply techniques from network theory and complexity science to assess adaptability and resilience. We present an analysis of connectivity in a network model of California's water infrastructure system using several network science techniques. Results indicate that nodes in California's water system are clustered but without scale-free properties. The network originates from a mixture of top-down (centralised) and bottom-up (dispersed interactions of parties) planning. This structu...

Risk and resilience: strategies for security

Abstract: Traditional approaches to security and safety are being challenged by ever-increasing complexity in today's socio-economic systems. New vulnerabilities are arising for many reasons: demographic shifts, trans-boundary networks, modern business practices, new systemic risks, and reliance on closely coupled infrastructure systems, among others. In such circumstances there needs to be greater allowance for uncertainty, and a different balance of proactive and reactive risk management. Decision-makers in both governments and the private sector require more comprehensive strategies that combine active management of specific risks with enhancement of generic resilience in society. Security will depend increasingly on community attributes such as social capital, informal communication networks, and organisational culture. As a general strategy for managing complex risks, this paper recommends a multilayered approach involving systems planning, risk management, resilience building, and adaptive responses.

Fuzzy approach for optimum replacement time of mixed infrastructures

Abstract: Investments in infrastructure assets represent a sizable portion in the governments’ public fund. Continuous maintenance, rehabilitation, and replacement are required to maintain the level of service of infrastructure assets. Knowing the replacement needs of infrastructures and the timing of replacement are challenging tasks. This paper presents a decision support tool that aids in deciding the best time to replace several types of infrastructure assets, that is, mixed infrastructure. The paper uses fuzzy logic to model uncertainties in order to identify the useful lifetime of each infrastructure asset. Infrastructure replacement decision is made based on least cost option(s). A fuzzy logic tool is applied in three steps: data fuzzification, fuzzy inference, and data defuzzification. The developments made in the fuzzy logic tool are presented. A numerical example is presented to demonstrate the practical features of the proposed tool.

Finding resilience through practical wisdom

Abstract: Delivering resilience will require innovative systems-thinking skills of practical wisdom that go beyond technique. Aristotle's notion of phronesis as practical wisdom, which was largely lost until contemporary thinking about virtue ethics, provides a basis for a modern interpretation. Resilience, risk, vulnerability, robustness and sustainability need to be set not just in the dominant paradigm of scientific/technical rationality but also within a reflective practice that nurtures practical wisdom and questions ‘why’ before ‘how’. Practical rigour, as part of practical wisdom, is the meeting of a need by setting clear objectives involving many values (some in ‘wicked’ conflict) and reaching those objectives in a demonstrably justifiable way. Seven elements in practical rigour are described. Two keys to delivering resilience are: (a) to allow professionals to publicly admit that we do not know when we genuinely do not know; (b) to integrate people, purpose and (old) process through collective practical wi...

Guiding principles for infrastructure climate change risk and adaptation studies

Abstract: As global climate mitigation actions increasingly appear to be unable to curb global emissions, there has been a corresponding increase in climate adaptation planning undertaken by governments and communities. Along with an increasing number of adaptation studies, there has been an increasing complexity of adaptation studies as practitioners attempt to plan the adaptation of whole communities, cities and in some cases nations. These studies are commonly underpinned by increasingly complex climate change vulnerability studies that also attempt to encompass concepts such as resilience and adaptive capacity. Owners and operators of infrastructure assets and networks also need to consider climate change. This need has been met by an increasing number of climate change risk and adaptation studies of major infrastructure. The approaches used for these assessments are commonly derived from assessments of whole communities and policy development studies, and apply terminology that is often inconsistent with estab...

Dam's risk identification under interval-valued intuitionistic fuzzy environment

Abstract: This paper uses both fuzzy analytic hierarchy process (FAHP) and the cross entropy of interval-valued intuitionistic fuzzy sets on risk identification of dams. The problem of risk identification can be transformed into a multi-criteria decision-making problem under fuzzy environment. Based on the weight of criteria calculated by the FAHP method and the interval-valued intuitionistic fuzzy information of risk aggregated by geometric average operator, the weight of each alternative can be obtained. The proposed method is used to identify the main risk factors of an earth–rock dam and to rank potential failure modes of the dam. The proposed method takes into account the interval unknown degree (hesitancy degree) in dam safety assessment and it is more effective and accurate in real conditions of dam operation.

Optimisation models to enhance resilience in evacuation planning

Abstract: We argue that the concepts of resilience in engineering science and robustness in mathematical optimisation are strongly related. Using evacuation planning as an example application, we demonstrate optimisation techniques to improve solution resilience. These include a direct modelling of the uncertainty for stochastic or robust optimisation as well as taking multiple objective functions into account.

Special Issue on Resilience

Abstract: This special issue – spanning the March and June 2015 issues of Civil Engineering and Environmental Systems (CEES) – is devoted to Resilience. Over the years, the Journal has featured a number of s...

Stochastic seismic analysis of Kömürhan Highway Bridge with varying material properties

Abstract: Stochastic seismic finite element analyses of the Komurhan Bridge, the material properties of which are described by random fields, are presented in this paper. The stochastic perturbation technique and Monte Carlo simulation (MCS) method are used in the analyses. A summary of MCS and perturbation-based stochastic finite element dynamic analysis formulation of the structural system is given. The Komurhan Bridge, located on the 51st km of Elazig-Malatya highway in the east of Turkey, was chosen as a numerical example. The Erzincan earthquake in 1992 was considered a ground motion, since it took place in the vicinity of the bridge. The material properties were considered to be random variables. During the stochastic analysis, displacements and internal forces of the bridge under consideration were obtained using the perturbation-based stochastic finite element method (SFEM), as well as the MCS method. The selected random variables were elastic modulus and mass density. The efficiency and accuracy of the pro...

Application of a new binary harmony search algorithm in highway rehabilitation decision-making problems: a case study in Iran

Abstract: Due to the importance of optimisation in highway rehabilitation projects and the shortcomings of mathematical programming in performing such a task at a quite reasonable runtime span, a new binary harmony search (BHS) is devised to accomplish the decision-making process of highway rehabilitation problems. A new formulation and a BHS are developed and applied to a case study problem consisting of 96 highway segments needing rehabilitation, a number of which should be selected to be rehabilitated at a fixed budget in order to maximise the total quality of the highway network with the minimum possible cost. The BHS provides the value 1 for the segments which must be reconstructed and 0 for the remaining. Pavement Condition Index is employed to assess the quality of the highway. Several sensitivity analyses were performed to examine the influence of different parameters on the output.

Reflective practice and technical rationality in construction project planning

Abstract: This study reviews relevant literature to identify the drawbacks of traditional planning algorithms related to technical rationality. It also evaluates the suitability of construction project strategies, to bring reflective practice into construction project planning by using an archival analysis approach. The archival analysis used qualitative data provided by the Chartered Institute of Building (CIOB), UK, for 66 construction projects that are recognised as being successfully delivered. The information was sorted and analysed via NVivo and content analysis, respectively. The findings show that the characteristics of reflective practice are predominant in the problems and strategic solutions mentioned in the CIOB qualitative information. This study emphasises that the two paradigms are not isolated, but associated through three distinct relationships. Recommendations are given for practitioners to use reflective practice, along with technical rationality to strategically solve problems encountered in con...

Is toughness a better metaphor than resilience

Abstract: Toughness is arguably a better metaphor than resilience to describe the characteristics of wider systems for which the term ‘resilience’ is currently employed. This argument is presented by describing the various features of a stress–strain curve, to which the two terms relate. In particular, it is the large energy-absorbing and strain capacities of the plastic region that make toughness a more apt metaphor. System toughness can be seen as having three aspects, namely robustness, redundancy and element toughness. Similarities are demonstrated between the analogical source of structural mechanics and two analogical targets, namely transportation and social systems. ‘Post-yield’ behaviour in such wider systems can be classified as to whether they are ductile or brittle; and as to whether they display strain hardening or strain softening.

The effect of structural properties and ground motion variables on the global response of structural systems

Abstract: The uncertainty in the seismic demand of a structure, corresponding to uncertainties in ground motion and in structural properties, needs to be properly characterised in a reliability analysis. In this study, the sensitivity of structural response to major uncertain variables is investigated using the variance-based method in order to determine which variables are most significant. The Sobol’ decomposition, based on a Monte Carlo simulation, is used to decompose the variance of the response into contributions from the individual ground motion and structural properties as input variables. The formulation of a dynamic structural response using the random-vibration theory, based only on the frequency information of the excitation, can provide an important basis for analytical sensitivity analysis of a structural response. The results show that the uncertainties in ground motion are more significant than uncertainties in structural properties for global structural response, especially peak roof displacement a...