This paper discusses the performance of road bridges during the 2010–2011 Canterbury earthquakes and focuses on the response of bridges in liquefying soils undergoing lateral spreading. A characteristic spreading-induced mechanism for short-span bridges with rigid superstructures is presented and explored using four well-documented case studies. A series of pseudo-static analyses are then used to investigate the observed response of the bridges and their pile foundations in particular. Deformations and damage to the piles are evaluated and correlated with the spreading displacements, and key factors controlling the pile response and the development of the spreading-induced damage mechanism are identified.

On 16 April 2016, a moment magnitude (Mw) 7.0 earthquake struck the Island of Kyushu, Japan. Two major foreshocks (Mw 6.2 and Mw 6.0) contributed to devastation in Kumamoto City, Mashiki Town and in the mountainous areas of the Mount Aso volcanic caldera. This report summarises geotechnical and geological aspects of the earthquakes that were observed during a field investigation conducted by the NZSEE Team in collaboration with Japanese engineers and researchers. Many houses and other buildings, roads, riverbanks, and an earth dam, either on or adjacent to the surface fault rupture or projected fault trace, were severely damaged as a result of both the strong ground shaking and permanent ground displacement. In the Mount Aso volcanic caldera, traces of medium to large scale landslides and rock falls were frequently observed. A number of landslides impacted homes and infrastructure, and were reported to have killed at least 10 people out of the 69 confirmed deaths associated with the earthquake. In a few suburbs of Kumamoto City and in Mashiki Town, localised liquefaction took place, causing lateral spreading, differential settlements of the ground and riverbanks, sinking and tilting of buildings, foundation failures, cracks on roads, and disruption of water and sewage pipe networks. The overall effects from liquefaction related hazards appeared relatively minor compared to the damage caused by shaking, landslides and surface fault rupture. Based on the field survey, key findings are highlighted and recommendations to NZ engineering practice are made in the report.

On 12 May 2008 at 2.28 pm Beijing Time, an Ms 8.0 earthquake occurred in the Wenchuan County of Sichuan province, China. The associated fault ruptured over 240 km on the ground surface. The resulting damage was very severe and widespread, with casualties of almost 70,000, another 18,000 missing and 370,000 injured. The New Zealand Society for Earthquake Engineering reconnaissance team observed the effects and the recovery from this massive earthquake. The team studied the damages caused to the natural and the built environment due to fault rupture, seismic shaking, huge landslides and rockfalls. Maximum shaking intensity of MM XI significantly exceeded design intensity of MM VII for the area. Earthquake induced landslides had a major and catastrophic impact on development and infrastructure in this earthquake. Site selection was demonstrated to be critical. Brittle or non-ductile and irregular buildings performed very poorly especially in a seismic overload situation. Well engineered structures and dams performed well. Lifeline facilities were severely damaged, which resulted in interruptions to key transportation routes, inhibited rescue and recovery operations.

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 Ward to Cheviot section of State Highway 1 is a key lifeline transport route that runs through the Kaikōura township.  It is a strategically important link in the national state highway network, connecting the North Island via the Wellington-Picton ferry to the city of Christchurch in the South Island.  Its strategic importance and vulnerable location between the mountainous Kaikōura range and the Pacific Ocean make it a critical transportation route in the national transport network.  The route has been a focus for understanding the resilience of transport networks from as far back as 2000, when this section was used as a pilot study in early research into transport resilience.  A further resilience assessment of this section was completed as part of a national state highway resilience study in mid-2016.  Subsequently, the Mw 7.8 Kaikōura earthquake struck the northeast of the South Island on 14 November 2016, triggering thousands of large landslides and causing severe disruption to the transport network.  The damage and disruption caused by the earthquake was comparable to that assessed in pre-earthquake studies of the resilience of the state highway.  Landslides and embankment failures caused the most damage and disruption to the transport infrastructure, with the Main North Line railway closed for over 9 months and State Highway 1 closed for over a year.  Post-earthquake landslides and debris flows triggered by storms caused additional damage and disruption during the recovery phase. Post-earthquake assessment of the corridor resilience was carried out to identify measures to enhance resilience as part of the recovery works.  These measures included realigning the road and rail away from the steep hillsides, engineered works to reduce the potential for slope failure, and engineered works to reduce the potential for inundation of the corridor.  The resilience assessments also enabled tactical and operational measures to be put in place to ensure safety while allowing the recovery operations to proceed in the context of enhanced risk associated with storm events and potential aftershocks.