As the cost of lifeline disruption rises with the size and complexity of urban communities, increasing efforts are put into enhancing infrastructure resilience to natural disasters. Aiming to improve the understanding of water supply network seismic resilience, this paper examines in detail the initial performance and restoration of the water supply network following the 22 February 2011 M w 6.2 Christchurch, New Zealand earthquake. In addition, a method to optimize the recovery of such systems is developed in two phases: the prioritization of pipe inspection and prioritization of pipe repairs. The results inferred from the observed pipe repairs suggest that the recovery was carried out efficiently; however, applying the proposed methodology would have substantially improved the recovery of the system with a 30% reduction in the number of buildings deprived of water in the first two days. Assumptions and limitations of the modeling are also discussed and practical solutions given to apply this framework in real-time for post-earthquake restoration.

The ambitious scopes of recent earthquake ground motion studies are generating a need for more high-quality ground motion records. As the number of deployed sensors is rapidly growing through improved accessibility and cost (e.g., ground motion stations, low-cost accelerometers, smart phones), an exponentially increasing amount of data are being generated. Previously, quality-assured ground motion data sets for engineering applications were generated using both manual and automated quality screening methodologies. More recently, new techniques have emerged that potentially offer both improved classification accuracy and computational expediency. This work presents a machine learning–oriented method to facilitate and accelerate the quality classification of ground motion records from small magnitude earthquakes. Feedforward neural networks are selected for their ability to efficiently recognize patterns and are trained on two New Zealand data sets. An application to physics-based ground motion simulation validation indicates that the proposed approach delivers results that are comparable with manual quality selection. Robust automatic ground motion quality screening allows a significant increase in data set size for development, calibration, and validation of ground motion models.

This paper presents parametric fragility functions for buried pressurized water pipelines based on data collected following the 22 February and 13 June 2011 events in the Canterbury, New Zealand earthquake sequence. The fragility of buried pipelines is expressed as a repair rate and utilizes the peak ground velocity, pipe characteristics, and soil liquefaction susceptibility expressed by the cyclic resistance ratio. The model explicitly takes into account both within-model uncertainty (the misfit to the data) and between-model uncertainty based on unknown model parameters such that for each unknown parameter, the between-model uncertainty increases. The adopted framework enables a wide application of these fragility functions to analyze the seismic performance of pressurized water pipeline networks, irrespective of the available information on the analyzed system. Utilized in a retrospective analysis via Monte Carlo simulations, the proposed fragility functions yield good predictive results.

This paper presents parametric fragility functions for buried pressurized water pipelines based on data collected following the 22 February and 13 June 2011 events in the Canterbury Earthquake Sequence. The fragility of buried pipelines is expressed as a failure rate and utilizes the peak ground velocity, pipe characteristics and soil liquefaction susceptibility expressed by the cyclic resistance ratio. The model explicitly takes into account both within-model uncertainty (the misfit to the data) as well as between-model uncertainty, based on unknown model parameters, such that for each unknown parameter the between-model uncertainty increases. The adopted framework enables a wide application of these fragility functions to analyse the seismic performance of pressurized water pipeline networks, irrespective of the available information on the analysed system. The proposed fragility functions are utilized in Monte-Carlo simulations with the ground motion intensities recorded following the aforementioned earthquakes to compare predicted and observed damage to the Christchurch water network.

This paper presents parametric fragility functions for buried pressurized water pipelines 6 based on data collected following the 22 February and 13 June 2011 events in the 7 Canterbury, New Zealand earthquake sequence. The fragility of buried pipelines is 8 expressed as a repair rate and utilizes the peak ground velocity, pipe characteris9 tics and soil liquefaction susceptibility expressed by the cyclic resistance ratio. The 10 model explicitly takes into account both within-model uncertainty (the misfit to the 11 data) as well as between-model uncertainty, based on unknown model parameters, 12 such that for each unknown parameter the between-model uncertainty increases. 13 The adopted framework enables a wide application of these fragility functions to 14 analyse the seismic performance of pressurized water pipeline networks, irrespec15 tive of the available information on the analysed system. Utilized in a retrospective 16 analysis via Monte-Carlo simulations, the proposed fragility functions yield good 17 predictive results. 18

We present preliminary observations on three waters impacts from the Mw7.8 14th November 2016 Kaikōura Earthquake on wider metropolitan Wellington, urban and rural Marlborough, and in Kaikōura township. Three waters systems in these areas experienced widespread and significant transient ground deformation in response to seismic shaking, with localised permanent ground deformation via liquefaction and lateral spreading. In Wellington, potable water quality was impacted temporarily by increased turbidity, and significant water losses occurred due to damaged pipes at the port. The Seaview and Porirua wastewater treatment plants sustained damage to clarifier tanks from water seiching, and increased water infiltration to the wastewater system occurred. Most failure modes in urban Marlborough were similar to the 2010-2011 Canterbury Earthquake Sequence; however some rural water tanks experienced rotational and translational movements, highlighting importance of flexible pipe connections. In Kaikōura, damage to reservoirs and pipes led to loss of water supply and compromised firefighting capability. Wastewater damage led to environmental contamination, and necessitated restrictions on greywater entry into the system to minimise flows. Damage to these systems necessitated the importation of tankered and bottled water, boil water notices and chlorination of the system, and importation of portaloos and chemical toilets. Stormwater infrastructure such as road drainage channels was also damaged, which could compromise condition of underlying road materials. Good operational asset management practices (current and accurate information, renewals, appreciation of criticality, good system knowledge and practical contingency plans) helped improve system resilience, and having robust emergency management centres and accurate Geographic Information System data allowed effective response coordination. Minimal damage to the wider built environment facilitated system inspections. Note Future research will include detailed geospatial assessments of seismic demand on these systems and attendant modes of failure, levels of service restoration, and collaborative development of resilience measures.

The magnitude Mw7.8 ‘Kaikōura’ earthquake occurred shortly after midnight on 14 November 2016. This paper presents an overview of the geotechnical impacts on the South Island of New Zealand recorded during the post-event reconnaissance. Despite the large moment magnitude of this earthquake, relatively little liquefaction was observed across the South Island, with the only severe manifestation occurring in the young, loose alluvial deposits in the floodplains of the Wairau and Opaoa Rivers near Blenheim. The spatial extent and volume of liquefaction ejecta across South Island is significantly less than that observed in Christchurch during the 2010-2011 Canterbury Earthquake Sequence, and the impact of its occurrence to the built environment was largely negligible on account of the severe manifestations occurring away from the areas of major development. Large localised lateral displacements occurred in Kaikōura around Lyell Creek. The soft fine-grained material in the upper portions of the soil profile and the free face at the creek channel were responsible for the accumulation of displacement during the ground shaking. These movements had severely impacted the houses which were built close (within the zone of large displacement) to Lyell Creek. The wastewater treatment facility located just north of Kaikōura also suffered tears in the liners of the oxidation ponds and distortions in the aeration system due to ground movements. Ground failures on the Amuri and Emu Plains (within the Waiau Valley) were small considering the large peak accelerations (in excess of 1g) experienced in the area. Minor to moderate lateral spreading and ejecta was observed at some bridge crossings in the area. However, most of the structural damage sustained by the bridges was a result of the inertial loading, and the damage resulting from geotechnical issues were secondary.