Sonia Giovinazzi

Resilience of the Canterbury Hospital System to the 2011 Christchurch Earthquake

The paper analyzes the performance of a hospital system using a holistic and multidisciplinary approach. Data on impacts to the hospital system were collected using a standardized survey tool. A fault-tree analysis method is adopted to assess the functionality of critical hospital services based on three main contributing factors: staff, structure, and stuff. Damage to utility networks and to nonstructural components was found to have the most significant effect on hospital functionality. The functional curve is integrated over time to estimate the resilience of the regional acute-care hospital with and without the redistribution of its major services. The ability of the hospital network to offer redundancies in services after the earthquake increased the resilience of the Christchurch Hospital by 12%. The resilience method can be used to assess future performance of hospitals, and to quantify the effectiveness of seismic retrofits, hospital safety legislation, and new seismic preparedness strategies.

Post-earthquake assessment and management for infrastructure systems: learning from the Canterbury (New Zealand) and L’Aquila (Italy) earthquakes

Both the April 6, 2009 L’Aquila (Italy) earthquake, and the 2010–2011 Canterbury (New Zealand) earthquake sequence provided unprecedented opportunity to enhance the understanding on earthquake performance of infrastructure systems, and to analyse still-opened issues affecting the post-earthquake assessment and management of infrastructure. This paper provides a succinct and holistic overview on the physical and functional performances of the gas, water, waste water, road and electric networks (this one to a limited extent for the L’Aquila case-study), following the moment magnitude (Mw) 6.3 L’Aquila earthquake, and two main events of the Canterbury earthquake sequence, namely: the Mw 7.1 September 4, 2010 Darfield and the Mw 6.2 February 22, 2011 Christchurch earthquakes. A structured format, based on internationally recognised taxonomies and damage descriptors, is introduced to present the assets and to report on the earthquake-induced physical impacts for both above-ground and underground components. Functional impacts, interdependency issues and resilience attributes observed during the emergency management and recovery phases for the same infrastructure systems are furthermore discussed in the paper. It is envisaged that the data and overview on the seismic performance and management of infrastructure systems presented in the paper can be used to test the effectiveness of existing models and to inform the development of new models for seismic risk assessment and resilience analysis. Also, the structured framework presented within this paper can form the basis for defining specific and standardised survey tools for post-earthquake assessment of infrastructure systems.

Wastewater Network Restoration Following the Canterbury, NZ Earthquake Sequence: Turning Post-Earthquake Recovery into Resilience Enhancement

The Canterbury earthquake sequence, 2010-2011, seriously impaired the wastewater network across much of the Canterbury region, New Zealand, by both seismic shock and liquefaction impact. This paper provides a preliminary overview of how infrastructure resilience is highlighted and built into rehabilitation practices and decision-making processes adopted by asset owners to reinstate the wastewater system in Christchurch. The physical damage suffered by the Christchurch wastewater system is briefly presented. Secondly, the decision-making processes for reconstructing the affected sewer system conducted by rebuild delivery agency - Stronger Christchurch Infrastructure Rebuild Team (SCIRT) as agreed by its clients: Christchurch City Council (CCC), Canterbury Earthquake Recovery Authority (CERA) and New Zealand Transport Agency (NZTA) are discussed with particular attention to the aims of achieving and enhancing infrastructure resilience. Furthermore, the paper describes how local and international experts have engaged with SCIRT, CCC and CERA to provide know-how in support of development of new Infrastructure Technical Standards and Guidelines that will underpin new design and construction of wastewater systems, describing the decision-making process that has resulted in the resilient rehabilitation of the Christchurch wastewater network.

Seismic performance of buried electrical cables: evidence-based repair rates and fragility functions

The fragility of buried electrical cables is often neglected in earthquakes but significant damage to cables was observed during the 2010–2011 Canterbury earthquake sequence in New Zealand. This study estimates Poisson repair rates, similar to those in existence for pipelines, using damage data retrieved from part of the electric power distribution network in the city of Christchurch. The functions have been developed separately for four seismic hazard zones: no liquefaction, all liquefaction effects, liquefaction-induced settlement only, and liquefaction-induced lateral spread. In each zone six different intensity measures (IMs) are tested, including peak ground velocity as a measure of ground shaking and five metrics of permanent ground deformation: vertical differential, horizontal, maximum, vector mean and geometric mean. The analysis confirms that the vulnerability of buried cables is influenced more by liquefaction than by ground shaking, and that lateral spread causes more damage than settlement alone. In areas where lateral spreading is observed, the geometric mean permanent ground deformation is identified as the best performing IM across all zones when considering both variance explained and uncertainty. In areas where only settlement is observed, there is only a moderate correlation between repair rate and vertical differential permanent ground deformation but the estimated model error is relatively small and so the model may be acceptable. In general, repair rates in the zone where no liquefaction occurred are very low and it is possible that repairs present in this area result from misclassification of hazard observations, either in the raw data or due to the approximations of the geospatial analysis. Along with hazard intensity, insulation material is identified as a critical factor influencing cable fragility, with paper-insulated lead covered armoured cables experiencing considerably higher repair rates than cross-linked polyethylene cables. The analysis shows no trend between cable age and repair rates and the differences in repair rates between conducting materials is shown not to be significant. In addition to repair rate functions, an example of a fragility curve suite for cables is presented, which may be more useful for analysis of network connectivity where cable functionality is of more interest than the number of repairs. These functions are one of the first to be produced for the prediction of damage to buried cables.

Seismic Fragility Functions for Sewerage Pipelines

Fragility functions (or fragility curves when presented graphically) are a well established tool to assess seismic risk to infrastructures. Given a sustained level of ground motion intensity, seismic fragility functions of sewerage pipelines are used for predicting earthquake-induced physical damage to sewer pipes. However, existing fragility functions of sewerage pipelines refer to a limited number of pipe types and material categories. Therefore practitioners often draw upon fragility functions specifically defined for potable-water pressure pipelines available in the international literature, for foreseeing earthquake-induced failures on sewerage gravity and pressure pipelines. The discrepancies between existing fragility curves and the observed physical damage data collected after the Canterbury (NZ) Earthquake sequence in 2010-2011, evidence that the fragility functions defined for potable-water pipelines tend to underestimate the physical damage to sewerage gravity pipelines. This paper proposes fragility functions for sewer gravity and pressure pipelines, categorized by pipe materials and liquefaction zones. The proposed fragility functions are developed using maximum likelihood estimation by correlating peak ground velocity with damage ratio (defined as number of faults per km) for sewer gravity pipes and with repair rate, defined as number of repairs per km for sewerage pressurized pipelines.

The Effectiveness of Existing Methodologies for Predicting Electrical Substation Damage Due to Earthquakes in New Zealand

This paper tests the applicability of two existing international methodologies, HAZUS (USA) and SYNER-G (Europe), for predicting electrical substation damage. It compares observed damage from the September 2010 and February 2011 Canterbury earthquakes in New Zealand with damage/failure probabilities generated by the two methodologies based on observed ground accelerations. Only two substations were damaged in the September earthquake and only one in the February earthquake. For both methodologies, failure probabilities were calculated for each substation and a short Monte Carlo simulation exercise was run, in which the probabilities were used to generate 1,000 potential city-wide damage scenarios. Both simulations yielded results which over-predicted the collective level of damage, with probabilities of less than 1 in 1000 that the observed scenarios could occur. This indicates that neither method is appropriate and that new fragility functions should be developed for New Zealand for future seismic risk assessments.

Earthquake-altered flooding hazard induced by damage to storm water systems

Abstract Major earthquakes can cause extensive transformations to the land underlying cities, leading to decreased capacity in natural and built drainage systems and, as a consequence, to Increased Flooding Hazard (IFH). This phenomenon causes some areas, which previously were not exposed to flooding, to have the potential to flood, and already flood-prone areas to likely experience increased flood depth during the next rainfall events. This scenario occurred in Christchurch city, New Zealand, after the 2010–2011 Canterbury Earthquake Sequence (CES). The IFH was observed in many urban areas during a series of rainfall events occurred in the years after the CES. This paper proposes a method for analysing and assessing to what extent the earthquake-induced damage to storm water pipelines and the consequent impacts on the connectivity and capacity levels of the pipeline storm water network could contribute to the IFH. A probabilistic analysis, through a Monte Carlo simulation, is suggested for the proposed method so that the uncertainty affecting several key parameters can be accounted for. The proposed probabilistic method for IFH was implemented as an additional module within a recently developed open-source simulation tool, OOFIMS. Results from the added OOFIMS module are presented in terms of maps and cumulative distribution functions of increased flood height and flooded area, impact metrics that can be useful for emergency managers and infrastructure owners. The effectiveness of the proposed method to assess earthquake-altered flooding hazard and the relative OOFIMS-added module are tested using Christchurch as a case-study.

Critical success factors for post-disaster infrastructure recovery: Learning from the Canterbury (NZ) earthquake recovery

Purpose The purpose of this paper is to synthesise critical success factors (CSFs) for advancing post-disaster infrastructure recovery and underpinning recovery authorities in decision making when facing future disasters. Design/methodology/approach The seismic recovery after the Canterbury (NZ) earthquake sequence in 2010-2011 was selected as a case study for identifying CSFs for an efficient recovery of infrastructure post-disaster. A combination of research approaches, including archival study, observations and semi-structured interviews were conducted for collecting data and evidences by engaging with participants involved at various tiers in the post-disaster recovery and reconstruction. The CSFs are evaluated and analysed by tracking the decision-making process, examining resultant consequences and foreseeing onwards challenges. Findings Six salient CSFs for strengthening infrastructure recovery management after disasters are identified. Furthermore, the study shows how each of these CSFs have been incorporated into the decision-making process in support of the post-disaster recovery and what difficulties encountered in the recovery process when implementing. Practical implications The proposed CSFs provide a future reference and guidance to be drawn on by decision makers when project-managing post-disaster recovery operations. Originality/value The value of the paper is that it bridges the gap between managerial contexts and technical aspects of post-disaster recovery process in an effort to rapidly and efficiently rebuild municipal infrastructure.

Postearthquake Decision Making on Sewer Recovery and the Roles of Damage and Repair Data: Case Study of Christchurch, New Zealand

AbstractDecision making on the reinstatement of the Christchurch sewer system after the Canterbury (New Zealand) earthquake sequence in 2010–2011 relied strongly on damage data, in particular close...

Performance of the healthcare facilities during the 2016–2017 Central Italy seismic sequence

This paper presents an overview on the response of the healthcare system in the area mostly affected by the 2016 Central Italy earthquake based on specific surveys and information from local health authorities. The authors collected in the field information on the seismic response capacity of the healthcare system. They surveyed five hospital complexes from medium to small dimension whose maximum capacity was up to 50 beds. This type of hospitals are representative of those ones present in the small towns located along the Apennines mountain range, usually including few buildings (i.e. 3–5) constructed in different periods and with different structural types. In all the surveyed hospitals there were partially or totally unusable buildings causing severe limitations to the functionality of the healthcare services, forcing to move many patients to other hospitals and to stop outpatient treatment. This was due mainly to severe damage to non-structural components and, in some cases, to moderate damage to structural components. In the present paper, two hospital case studies, namely “Tolentino” and “San Severino” hospitals, both located in Marche region, are analysed and discussed in detail in order to better understand their performance to the earthquakes, by also estimating their seismic risk via simplified methods, including the WHO Safety Index and the Cosenza and Manfredi (in: Fajfar and Krawinkler (eds) Seismic design methodologies for the next generation of codes, Balkema, Rotterdam, 1997) damage index.