Chloride Penetration in Circular Concrete Columns

Most of the diffusion models of chloride ions in reinforced concrete (RC) elements proposed in literature are related to an isotropic homogeneous semi-infinite medium. This assumption reduces the mathematical complexity, but it is correct only for plane RC elements. This work proposes a comparison between the diffusion model of chloride ions in RC circular columns and in RC slab elements. The durability of RC cylindric elements estimated with the circular model instead of the plane model is shown to be shorter. Finally, a guideline is formulated to properly use the standard and more simple plane model instead of the circular one to estimate the time to corrosion initiation of cylindrical RC elements

Toolkit for resilience assessment of critical infrastructures to earthquake induced soil liquefaction disasters

The critical infrastructure resilience depends on several factors that go beyond the physical reliability and capacity to repair the system after a disruption. The overall critical infrastructure resilience includes aspects related to the social and economic backbone governing its capacity to deliver its service. This contribution presents a theoretical toolkit to calculate the overall resilience of critical infrastructures developed within the European project LIQUEFACT for earthquakeinduced soil liquefaction disasters. The toolkit combine several aspects organized in three dimensions: organizational and management, the physical or technical system and operational capacity to deliver the service. The toolkit clearly defines also resilience aspects, such as preparedness, absorption, recovery and adaptation. For each dimension and aspect of the resilience several indicators are developed. A critical and technical explanation of each indicator is here proposed, as well a systematic methodology to combine them in the resilience toolkit. The novelty of this study is the systematic analysis of dimensions, aspects and indicators that made the proposed resilience toolkit original. The study is concluded with analyses of feasibility of the toolkit to natural disasters and applicability to localized disasters, such as earthquake-induced soil liquefaction events. Finally, the key factors of toolkit influencing a built asset model of critical infrastructures are identified

Facilities management and earthquake risk reduction: The TURNkey project

Reducing vulnerability and improving resilience of the existing built environment to disaster events is a complex multidisciplinary challenge in which facilities managers need to contribute an understanding of the impact that a disaster event could have on both their hard and soft facilities. Facilities managers also need to identify potential operational, physical and corporate adaptations/mitigations that can support continued business function during and after a disaster event. This paper describes work in progress to develop an earthquake forecasting, early warning and rapid response system that business and critical infrastructure organisations can use as part disaster risk reduction and business continuity planning. Focusing on theory and methods, the paper considers the different aspects of resilience from a facilities management perspective and presents findings from a participatory action research programme that developed a series of use-cases to explore the potential impact of earthquake forecasting, early warning and rapid response on an organisation's vulnerability and resilience to an earthquake; and identifying physical, operational and organisational mitigation interventions that can reduce an organisation's disaster risk. The paper concludes the need for facilities managers to understand the different aspects of resilience and to apply the most appropriate to their hard and soft facilities management system

Improving the resilience of existing built assets to earthquake induced liquefaction disaster events

LIQUEFACT was a EU H2020 funded project to investigate earthquake induced liquefaction potential across Europe and develop a series of tools to understand better the impacts that earthquake induced liquefaction disaster events have on the resilience of built assets and communities. A Resilience Assessment and Improvement Framework was developed to provide the theoretical underpinning for the LIQUEFACT project and to provide practical guidance on the assessment of built assets to Earthquake Induced Liquefaction Disaster events through the LIQUEFACT software tool and built asset management planning framework. This paper outlines the theoretical basis to the Resilience Assessment and Improvement Framework and built asset management planning framework and presents the results from a validation exercise through their application to a hypothetical healthcare scenario. The paper also describes the different stages of the research that led to the definition of the Resilience Assessment and Improvement Framework and built asset management planning framework. To this end the paper concludes that the Resilience Assessment and Improvement Framework and built asset management framework provide a longitudinal, holistic view of disaster vulnerability and resilience that can inform the selection of ground improvement mitigation actions to improve business continuity and resilience planning

Critical evaluation of the customization process of the UNDRR disaster resilience scorecard for cities to earthquake-induced soil liquefaction disasters events

As cities become larger and more densely populated the impacts of major earthquake events on city communities become more severe. Improving community resilience to earthquake events relies on the complex relationships that exist between different community stakeholder groups (citizens, businesses, community groups, emergency services, critical infrastructure providers, politicians etc.). This paper reports results from a major EU funded study (LIQUEFACT) that developed a tool for assessing community resilience to Earthquake Induced Liquefaction Disaster (EILD) events. The tool is based on a customised version of the UNDRR Disaster Resilience Scorecard for Cities. The paper reviews alternative approaches to measuring community resilience and describes the process used in the LIQUEFACT project to develop and validate the customised scorecard. The paper presents the results of a questionnaire survey to identify the best generic approach to measure community resilience and a series of semi-structured group interviews to define a range of specific metrics for assessing community resilience to EILD events; and the results of a validation workshop to assess the effectiveness and usability of the customised scorecard. The paper concludes that it is possible to develop a customised version of the UNDRR Scorecard at an appropriate level of granularity to support improved community resilience to earthquake induced soil liquefaction disaster events. The paper also presents key lessons that could assist those developing similar customised versions of the UNDRR scorecard for use in different geographical settings or against different disaster scenarios

Cost-benefit analysis of liquefaction mitigation strategies

This paper presents a cost-benefit model as part of the options appraisal process to evaluate alternative ground mitigation interventions to reduce vulnerability and/or improve resilience of built assets to earthquake induced liquefaction disaster (EILD) events. The paper presents a review of alternative approaches to cost-benefit analysis and develops forward looking (risk based) and backward looking (impact based) cost-benefit models that can be used by practitioners and policy makers to improve community resilience through better contingency and disaster management planning. The paper customises the models against EILD scenarios and identifies the cost and benefit attributes that need to be assessed if the models are to be effectively integrated into a resilience assessment and improvement framework for improved community resilience to EILD events

Cost Benefit Analysis to Appraise Technical Mitigation Options for Earthquake Induced Liquefaction Disaster Events

Purpose- Recent earthquake-induced liquefaction events and associated losses have increased researchers’ interest into liquefaction risk reduction interventions. To the best of the authors’ knowledge, there was no scholarly literature related to an economic appraisal of these risk reduction interventions. The purpose of this paper is to investigate the issues in applying cost–benefit analysis (CBA) principles to the evaluation of technical mitigations to reduce earthquake-induced liquefaction risk. Design/methodology/approach- CBA has been substantially used for risk mitigation option appraisal for a number of hazard threats. Previous literature in the form of systematic reviews, individual research and case studies, together with liquefaction risk and loss modelling literature, was used to develop a theoretical model of CBA for earthquake-induced liquefaction mitigation interventions. The model was tested using a scenario in a two-day workshop. Findings- Because liquefaction risk reduction techniques are relatively new, there is limited damage modelling and cost data available for use within CBAs. As such end users need to make significant assumptions when linking the results of technical investigations of damage to built-asset performance and probabilistic loss modelling resulting in many potential interventions being not cost-effective for low-impact disasters. This study questions whether a probabilistic approach should really be applied to localised rapid onset events like liquefaction, arguing that a deterministic approach for localised knowledge and context would be a better base for the cost-effectiveness mitigation interventions. Originality/value- This paper makes an original contribution to literature through a critical review of CBA approaches applied to disaster mitigation interventions. Further, this paper identifies challenges and limitations of applying probabilistic based CBA models to localised rapid onset disaster events where human losses are minimal and historic data is sparse; challenging researchers to develop new deterministic based approaches that use localised knowledge and context to evaluate the cost-effectiveness of mitigation interventions