Dept. of Civil and Environmental Engineering, University of Surrey, UK; Dept. of Civil Engineering, Aristotle University, Thessaloniki, Greece.
Dept. of Civil and Environmental Engineering, University of Surrey, UK.
Sci Total Environ. 2020 Apr 20;714:136854. doi: 10.1016/j.scitotenv.2020.136854. Epub 2020 Jan 22.
The exposure of critical infrastructure to natural and human-induced hazards has severe consequences on world economies and societies. Therefore, resilience assessment of infrastructure assets to extreme events and sequences of diverse hazards is of paramount importance for maintaining their functionality. Yet, the resilience assessment commonly assumes single hazards and ignores alternative approaches and decisions in the restoration strategy. It has now been established that infrastructure owners and operators consider different factors in their restoration strategies depending on the available resources and their priorities, the importance of the asset and the level of damage. Currently, no integrated framework that accounts for the nature and sequence of multiple hazards and their impacts, the different strategies of restoration, and hence the quantification of resilience in that respect exists and this is an acknowledged gap that needs urgently filling. This paper provides, for the first time in the literature, a classification of multiple hazard sequences considering their nature and impacts. Subsequently, a novel framework for the quantitative resilience assessment of critical infrastructure, subjected to multiple hazards is proposed, considering the vulnerability of the assets to hazard actions, and the rapidity of the damage recovery, including the temporal variability of the hazards. The study puts forward a well-informed asset resilience index, which accounts for the full, partial or no restoration of asset damage between the subsequent hazard occurrences. The proposed framework is then applied on a typical highway bridge, which is exposed to realistic multiple hazard scenarios, considering pragmatic restoration strategies. The case study concludes that there is a significant effect of the occurrence time of the second hazard on the resilience index and a considerable error when using simple superimposition of resilience indices from different hazards, even when they are independent in terms of occurrence. This potentially concerns all critical infrastructure assets and, hence, this paper provides useful insights for the resilience-based design and management of infrastructure throughout their lifetime, leading to cost savings and improved services. The paper concludes with a demonstration of the importance of the framework and how this can be utilised to estimate the resilience of networks to provide a quantification of the resilience at a regional and country scale.
关键基础设施面临自然和人为灾害的风险，会对世界经济和社会造成严重后果。因此，评估基础设施资产对极端事件和多种灾害序列的恢复力，对于维持其功能至关重要。然而，恢复力评估通常只考虑单一灾害，而忽略了恢复策略中的替代方法和决策。现在已经确定，基础设施所有者和运营商在其恢复策略中会根据可用资源及其优先级、资产的重要性和损坏程度考虑不同的因素。目前，还没有一个综合框架可以考虑多种灾害的性质和序列及其影响、不同的恢复策略，因此无法在这方面量化恢复力，这是一个公认的需要紧急填补的空白。本文首次在文献中提供了一种考虑多种灾害性质和影响的灾害序列分类。随后，提出了一种新的考虑多种灾害的关键基础设施定量恢复力评估框架，考虑了资产对灾害作用的脆弱性和损坏的快速恢复能力，包括灾害的时间变化性。该研究提出了一个明智的资产恢复力指数，该指数考虑了资产损坏在随后发生的灾害之间的完全、部分或无恢复情况。然后，该框架应用于典型的公路桥梁，该桥梁面临现实的多种灾害情景，并考虑了实际的恢复策略。案例研究得出的结论是，第二次灾害发生的时间对恢复力指数有显著影响，即使在不同灾害独立发生的情况下，简单叠加不同灾害的恢复力指数也会产生很大的误差。这可能涉及所有关键基础设施资产，因此，本文为基础设施的基于恢复力的设计和管理提供了有用的见解，可在整个生命周期内节省成本并提高服务质量。本文最后演示了该框架的重要性，以及如何利用该框架来估计网络的恢复力，以量化区域和国家层面的恢复力。
