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Images, UC QuakeStudies

A photograph of a member of the Wellington Emergency Management Office Emergency Response Team standing on the bank of the Avon River. In the background are the remains of the collapsed PGC Building. An excavator is on top of these remains, working to clear them away.

Images, UC QuakeStudies

A photograph of a member of the Wellington Emergency Management Office Emergency Response Team standing on the bank of the Avon River. In the background are the remains of the collapsed PGC Building. An excavator is on top of these remains, working to clear them away.

Research papers, University of Canterbury Library

The 4 September 2010 Darfield and 22 February 2011 Christchurch earthquakes caused significant damage to Christchurch and surrounding suburbs as a result of the widespread liquefaction and lateral spreading that occurred. Ground surveying-based field investigations were conducted following these two events in order to measure permanent ground displacements in areas significantly affected by lateral spreading. Data was analysed with respect to the distribution of lateral spreading vs. distance from the waterway, and the failure patterns observed. Two types of failure distribution patterns were observed, a typical distributed pattern and an atypical block failure. Differences in lateral spreading measurements along adjacent banks of the Avon River in the area of Dallington were also examined. The spreading patterns between the adjacent banks varied with the respective river geometry and/or geotechnical conditions at the banks.

Images, UC QuakeStudies

A photograph captioned by BeckerFraserPhotos, "A section of Avonside Drive shows how the infrastructure is no longer maintained to the same level, with regard to roading, sewage and water services. Even the grass on the banks of the River Avon is no longer mown as regularly".

Images, UC QuakeStudies

A digitally manipulated photograph of the badly twisted Medway Street footbridge. The photographer comments, "This bridge over the Avon River in Christchurch, New Zealand has been left in place since the first major earthquake back in September 2010. Graffiti artists or taggers are still leaving their marks on it even though it is nearly twisted at 90 degrees at one point".

Images, eqnz.chch.2010

Low tide on the Avon River at New Brighton/Bexley. Note the original bank and the rock wall slipage on right. The white additions were added in March and April 2011 to protect the properties behind from flooding. Ultimately this area was "red zoned" with all houses removed or to be removed and the ground left till a rehabilitation method can ...

Images, eqnz.chch.2010

With the land dropping about 1metre to 1.4metres after the earthquakes, a few roads besides the Avon and Heathcote Rivers are flooded with very high tides. Extra stop banks (on right) erected after the quakes have helped, but the road is now well below high water level. New Brighton Road, just short of New Brighton. The Pages Road bridge may b...

Research papers, The University of Auckland Library

The Darfield earthquake caused widespread damage in the Canterbury region of New Zealand, with the majority of damage resulting from liquefaction and lateral spreading. One of the worst hit locations was the small town of Kaiapoi north of Christchurch, an area that has experienced liquefaction during past events and has been identified as highly susceptible to liquefaction. The low lying town sits on the banks of the Kaiapoi River, once a branch of the Waimakariri, a large braided river transporting gravelly sediment. The Waimakariri has been extensively modified both by natural and human processes, consequently many areas in and around the town were once former river channels.

Images, UC QuakeStudies

A photograph captioned by BeckerFraserPhotos, "Rose and Richard in front of their house at 464 Avonside Drive. They decided to only move once, so are staying in Avonside Drive while Richard completes the build of their new home. Rose is keeping an eye on the neighbourhood during her daily walks along the river bank".

Videos, UC QuakeStudies

A video of the removal of the earthquake-damaged Medway Street bridge from the banks of the Avon River. The video shows members of the Stronger Christchurch Infrastructure Rebuild Team removing the bridge and preparing it for transport to the Ferrymead Heritage Park. It will remain at the park until a permanent home can be found for it as an earthquake memorial.

Audio, Radio New Zealand

Pike River Mine will be put up for sale soon, People allowed into another area of Christchurch cordon, Relative, friends of quake lost describe pain of waiting, Doubts swirl around Rugby World Cup in Christchurch and the ongoing questions surrounding the death of a New Zealander and other tourists in Thailand, Earthquake puts unprecedented pressure on Reserve Bank, Sovereign may not be last failure in struggling building sector, Space shuttle Discovery lands safely in Florida.

Images, eqnz.chch.2010

Further damage to the bank following the two quakes on 23/12/11. The sewer line broke here and was repaired (patched) by council staff on Christmas Eve. It is hard to beleve that this rock wall was level with the land here, before any of the quakes.

Research papers, University of Canterbury Library

Coastal and river environments are exposed to a number of natural hazards that have the potential to negatively affect both human and natural environments. The purpose of this research is to explain that significant vulnerabilities to seismic hazards exist within coastal and river environments and that coasts and rivers, past and present, have played as significant a role as seismic, engineering or socio-economic factors in determining the impacts and recovery patterns of a city following a seismic hazard event. An interdisciplinary approach was used to investigate the vulnerability of coastal and river areas in the city of Christchurch, New Zealand, following the Canterbury Earthquake Sequence, which began on the 4th of September 2010. This information was used to identify the characteristics of coasts and rivers that make them more susceptible to earthquake induced hazards including liquefaction, lateral spreading, flooding, landslides and rock falls. The findings of this research are applicable to similar coastal and river environments elsewhere in the world where seismic hazards are also of significant concern. An interdisciplinary approach was used to document and analyse the coastal and river related effects of the Canterbury earthquake sequence on Christchurch city in order to derive transferable lessons that can be used to design less vulnerable urban communities and help to predict seismic vulnerabilities in other New Zealand and international urban coastal and river environments for the future. Methods used to document past and present features and earthquake impacts on coasts and rivers in Christchurch included using maps derived from Geographical Information Systems (GIS), photographs, analysis of interviews from coastal, river and engineering experts, and analysis of secondary data on seismicity, liquefaction potential, geology, and planning statutes. The Canterbury earthquake sequence had a significant effect on Christchurch, particularly around rivers and the coast. This was due to the susceptibility of rivers to lateral spreading and the susceptibility of the eastern Christchurch and estuarine environments to liquefaction. The collapse of river banks and the extensive cracking, tilting and subsidence that accompanied liquefaction, lateral spreading and rock falls caused damage to homes, roads, bridges and lifelines. This consequently blocked transportation routes, interrupted electricity and water lines, and damaged structures built in their path. This study found that there are a number of physical features of coastal and river environments from the past and the present that have induced vulnerabilities to earthquake hazards. The types of sediments found beneath eastern Christchurch are unconsolidated fine sands, silts, peats and gravels. Together with the high water tables located beneath the city, these deposits made the area particularly susceptible to liquefaction and liquefaction-induced lateral spreading, when an earthquake of sufficient size shook the ground. It was both past and present coastal and river processes that deposited the types of sediments that are easily liquefied during an earthquake. Eastern Christchurch was once a coastal and marine environment 6000 years ago when the shoreline reached about 6 km inland of its present day location, which deposited fine sand and silts over this area. The region was also exposed to large braided rivers and smaller spring fed rivers, both of which have laid down further fine sediments over the following thousands of years. A significant finding of this study is the recognition that the Canterbury earthquake sequence has exacerbated existing coastal and river hazards and that assessments and monitoring of these changes will be an important component of Christchurch’s future resilience to natural hazards. In addition, patterns of recovery following the Canterbury earthquakes are highlighted to show that coasts and rivers are again vulnerable to earthquakes through their ability to recovery. This city’s capacity to incorporate resilience into the recovery efforts is also highlighted in this study. Coastal and river areas have underlying physical characteristics that make them increasingly vulnerable to the effects of earthquake hazards, which have not typically been perceived as a ‘coastal’ or ‘river’ hazard. These findings enhance scientific and management understanding of the effects that earthquakes can have on coastal and river environments, an area of research that has had modest consideration to date. This understanding is important from a coastal and river hazard management perspective as concerns for increased human development around coastlines and river margins, with a high seismic risk, continue to grow.

Audio, Radio New Zealand

A review of the week's news including: national earthquake memorial service announced, former defence chief to be new Governor General, Reserve Bank slashes official cash rate, Christchurch businesses say OCR cut alone won't save them, mounting concern over Christchurch World Cup prospects, government says 10,000 Christchurch homes will be demolished, alarm over possibility of mass demolition in CBD, international crews head home, petrol prices at three year high, Pike River mine receivers take control from police and boulder sold for thousands in aid of Christchurch

Audio, Radio New Zealand

Thousands of people in Christchurch and around the country paused at 12.51 on Monday afternoon to mark a decade since the February 22 magnitude 6.3 earthquake which claimed 185 lives. It was 10 years ago today when an ordinary Christchurch day turned to hell for so many. But in contrast to the harrowing scenes and sounds of that day, today a large peaceful crowd gathered at the Civic Memorial Service on the banks of the Avon River under large oak trees. Reporter Sally Murphy and cameraman Nate McKinnon were there.

Audio, Radio New Zealand

A 22-year-old self-employed dairy farmer hopes his success through winning a new Maori farming award will inspire other young troubled Maori to follow their dreams; The Chairperson of Nelson's first Maori language immersion school says there's been a shift in attitude among members of the public - who now understand the school won't be exclusive; The former National MP Sandra Goudie is calling for Waikato ratepayers to oppose two Maori seats that the Regional Council is introducing at next year's election; Liquefaction from the Christchurch earthquakes may have unearthed four taonga on the banks of the Heathcote river.

Audio, Radio New Zealand

The former National MP Sandra Goudie is calling for Waikato ratepayers to oppose two Maori seats that the Regional Council is introducing at next year's election; The Chairperson of Nelson's first Maori language immersion school says there's been a shift in attitude among members of the public - who now understand the school won't be exclusive; A 22-year-old self-employed dairy farmer hopes his success through winning a new Maori farming award will inspire other young troubled Maori to follow their dreams; Liquefaction from the Christchurch earthquakes may have unearthed four taonga on the banks of the Heathcote river.

Research papers, University of Canterbury Library

In the aftermath of the 2010-2011 Canterbury Earthquake Sequence (CES), the location of Christchurch-City on the coast of the Canterbury Region (New Zealand) has proven crucial in determining the types of- and chains of hazards that impact the city. Very rapidly, the land subsidence of up to 1 m (vertical), and the modifications of city’s waterways – bank sliding, longitudinal profile change, sedimentation and erosion, engineered stop-banks… - turned rainfall and high-tides into unprecedented floods, which spread across the eastern side of the city. Within this context, this contribution presents two modeling results of potential floods: (1) results of flood models and (2) the effects of further subsidence-linked flooding – indeed if another similar earthquake was to strike the city, what could be the scenarios of further subsidence and then flooding. The present research uses the pre- and post-CES LiDAR datasets, which have been used as the boundary layer for the modeling. On top of simple bathtub model of inundation, the river flood model was conducted using the 2-D hydrodynamic code NAYS-2D developed at the University of Hokkaido (Japan), using a depth-averaged resolution of the hydrodynamic equations. The results have shown that the area the most at risk of flooding are the recent Holocene sedimentary deposits, and especially the swamplands near the sea and in the proximity of waterways. As the CES drove horizontal and vertical displacement of the land-surface, the surface hydrology of the city has been deeply modified, increasing flood risks. However, it seems that scientists and managers haven’t fully learned from the CES, and no research has been looking at the potential future subsidence in further worsening subsidence-related floods. Consequently, the term “coastal quake”, coined by D. Hart is highly topical, and most especially because most of our modern cities and mega-cities are built on estuarine Holocene sediments.

Research papers, University of Canterbury Library

Spatial variations in river facies exerted a strong influence on the distribution of liquefaction features observed in Christchurch during the 2010-11 Canterbury Earthquake Sequence (CES). Liquefaction and liquefaction-induced ground deformation was primarily concentrated near modern waterways and areas underlain by Holocene fluvial deposits with shallow water tables (< 1 to 2 m). In southern Christchurch, spatial variations of liquefaction and subsidence were documented in the suburbs within inner meander loops of the Heathcote River. Newly acquired geospatial data, geotechnical reports and eye-witness discussions are compiled to provide a detailed account of the surficial effects of CES liquefaction and ground deformation adjacent to the Heathcote River. LiDAR data and aerial photography are used to produce a new series of original figures which reveal the locations of recurrent liquefaction and subsidence. To investigate why variable liquefaction patterns occurred, the distribution of surface ejecta and associated ground damage is compared with near-surface sedimentologic, topographic, and geomorphic variability to seek relationships between the near-surface properties and observed ground damages. The most severe liquefaction was concentrated within a topographic low in the suburb of St Martins, an inner meander loop of the Heathcote River, with liquefaction only minor or absent in the surrounding areas. Subsurface investigations at two sites in St Martins enable documentation of fluvial stratigraphy, the expressions of liquefaction, and identification of pre-CES liquefaction features. Excavation to water table depths (~1.5 m below the surface) across sand boils reveals multiple generations of CES liquefaction dikes and sills that cross-cut Holocene fluvial and anthropogenic stratigraphy. Based on in situ geotechnical tests (CPT) indicating sediment with a factor of safety < 1, the majority of surface ejecta was sourced from well-sorted fine to medium sand at < 5 m depth, with the most damaging liquefaction corresponding with the location of a low-lying sandy paleochannel, a remnant river channel from the Holocene migration of the meander in St Martins. In the adjacent suburb of Beckenham, where migration of the Heathcote River has been laterally confined by topography associated with the volcanic lithologies of Banks Peninsula, severe liquefaction was absent with only minor sand boils occurring closest to the modern river channel. Auger sampling across the suburb revealed thick (>1 m) clay-rich overbank and back swamp sediments that produced a stratigraphy which likely confined the units susceptible to liquefaction and prevented widespread ejection of liquefied material. This analysis suggests river migration promotes the formation and preservation of fluvial deposits prone to liquefaction. Trenching revealed the strongest CES earthquakes with large vertical accelerations favoured sill formation and severe subsidence at highly susceptible locations corresponding with an abandoned channel. Less vulnerable sites containing deeper and thinner sand bodies only liquefied in the strongest and most proximal earthquakes forming minor localised liquefaction features. Liquefaction was less prominent and severe subsidence was absent where lateral confinement of a Heathcote meander has promoted the formation of fluvial stratum resistant to liquefaction. Correlating CES liquefaction with geomorphic interpretations of Christchurch’s Heathcote River highlights methods in which the performance of liquefaction susceptibility models can be improved. These include developing a reliable proxy for estimating soil conditions in meandering fluvial systems by interpreting the geology and geomorphology, derived from LiDAR data and modern river morphology, to improve the methods of accounting for the susceptibility of an area. Combining geomorphic interpretations with geotechnical data can be applied elsewhere to identify regional liquefaction susceptibilities, improve existing liquefaction susceptibility datasets, and predict future earthquake damage.

Audio, Radio New Zealand

In this edition: The report into the collapse of the CTV building in the Christchurch earthquake a year ago is released, the Maori Council lodges claims with the Waitangi tribunal that could throw a spanner in the works of the Government's asset sales programme, the Earthquake Recovery Minister nearing the end of his tether with the Christchurch City Council, more from the Pike River Royal Commission, Radio Live could face a potential one hundred thousand dollar fine under the electoral act over John Key's hour long radio show in the run up to the 2011 election, banks lift their collective profits for the second half of 2011 by 25 percent and the winners are announced at the 2012 Halberg Awards.

Videos, NZ On Screen

This 1974 end of year special for music show Popco features cover songs performed in the studio and around Christchurch. Presenting and singing are Rob Guest (before musicals fame), Steve Gilpin (before he founded Mi-Sex) and Hayden Wood. Joining them are Space Waltz (in their glam rock glory), Annie Whittle (on the banks of the Avon), show regulars the Maggie Burke Dancers in Cathedral Square, Mark Williams (sparkling in green lurex), Bunny Walters and Claire Raine, Rockinghorse (featuring 'Nature' composer Wayne Mason), Drut (complete with flaming guitar) and Beaver (in the finale).

Audio, Radio New Zealand

Kim Hill talks to Sam Crofskey, the owner of C1 Espresso in the Christchurch CBD, which reopened in 2012 after the Canterbury earthquakes and will celebrate its twentieth anniversary this year. He spoke on the WORD Christchurch panel, How Are We Doing, Christchurch?, and this week launched Let's Take a Walk, a pop-up book for children about the quakes that he created with his wife Fleur and illustrator Hannah Beehre. He is joined by Joseph Hullen (Ngai Tuahuriri, Ngai Tahu), a hunter gatherer, fisherman, explorer, kaitiaki and storyteller who has spent a lifetime gathering traditional kai and listening to stories about his hapu. He is a whakapapa researcher for Te Runanga o Ngai Tahu, and is leading three sold-out walking tours during WORD Christchurch along the banks of the Otakaro (Avon River), uncovering the city's history.

Research Papers, Lincoln University

We examined the stratigraphy of alluvial fans formed at the steep range front of the Southern Alps at Te Taho, on the north bank of the Whataroa River in central West Coast, South Island, New Zealand. The range front coincides with the Alpine Fault, an Australian-Pacific plate boundary fault, which produces regular earthquakes. Our study of range front fans revealed aggradation at 100- to 300-year intervals. Radiocarbon ages and soil residence times (SRTs) estimated by a quantitative profile development index allowed us to elucidate the characteristics of four episodes of aggradation since 1000 CE. We postulate a repeating mode of fan behaviour (fan response cycle [FRC]) linked to earthquake cycles via earthquake-triggered landslides. FRCs are characterised by short response time (aggradation followed by incision) and a long phase when channels are entrenched and fan surfaces are stable (persistence time). Currently, the Te Taho and Whataroa River fans are in the latter phase. The four episodes of fan building we determined from an OxCal sequence model correlate to Alpine Fault earthquakes (or other subsidiary events) and support prior landscape evolution studies indicating ≥M7.5 earthquakes as the main driver of episodic sedimentation. Our findings are consistent with other historic non-earthquake events on the West Coast but indicate faster responses than other earthquake sites in New Zealand and elsewhere where rainfall and stream gradients (the basis for stream power) are lower. Judging from the thickness of fan deposits and the short response times, we conclude that pastoral farming (current land-use) on the fans and probably across much of the Whataroa River fan would be impossible for several decades after a major earthquake. The sustainability of regional tourism and agriculture is at risk, more so because of the vulnerability of the single through road in the region (State Highway 6).

Research papers, University of Canterbury Library

Liquefaction-induced lateral spreading in large seismic events often results in pervasive and costly damage to engineering structures and lifelines, making it a critical component of engineering design. However, the complex nature of this phenomenon leads to designing for such a hazard extremely challenging and there is a clear for an improved understanding and predicting liquefaction-induced lateral spreading. The 2010-2011 Canterbury (New Zealand) Earthquakes triggered severe liquefaction-induced lateral spreading along the streams and rivers of the Christchurch region, causing extensive damage to roads, bridges, lifelines, and structures in the vicinity. The unfortunate devastation induced from lateral spreading in these events also rendered the rare opportunity to gain an improved understanding of lateral spreading displacements specific to the Christchurch region. As part of this thesis, the method of ground surveying was employed following the 4 September 2010 Darfield (Mw 7.1) and 22 February 2011 Christchurch (Mw 6.2) earthquakes at 126 locations (19 repeated) throughout Christchurch and surrounding suburbs. The method involved measurements and then summation of crack widths along a specific alignment (transect) running approximately perpendicular to the waterway to indicate typically a maximum lateral displacement at the bank and reduction of the magnitude of displacements with distance from the river. Rigorous data processing and comparisons with alternative measurements of lateral spreading were performed to verify results from field observations and validate the method of ground surveying employed, as well as highlight the complex nature of lateral spreading displacements. The welldocumented field data was scrutinized to gain an understanding of typical magnitudes and distribution patterns (distribution of displacement with distance) of lateral spreading observed in the Christchurch area. Maximum displacements ranging from less than 10 cm to over 3.5 m were encountered at the sites surveyed and the area affected by spreading ranged from less than 20 m to over 200 m from the river. Despite the highly non-uniform displacements, four characteristic distribution patterns including large, distributed ground displacements, block-type movements, large and localized ground displacements, and areas of little to no displacements were identified. Available geotechnical, seismic, and topographic data were collated at the ground surveying sites for subsequent analysis of field measurements. Two widely-used empirical models (Zhang et al. (2004), Youd et al. (2002)) were scrutinized and applied to locations in the vicinity of field measurements for comparison with model predictions. The results indicated generally poor correlation (outside a factor of two) with empirical predictions at most locations and further validated the need for an improved, analysis- based method of predicting lateral displacements that considers the many factors involved on a site-specific basis. In addition, the development of appropriate model input parameters for the Youd et al. (2002) model led to a site-specific correlation of soil behavior type index, Ic, and fines content, FC, for sites along the Avon River in Christchurch that matched up well with existing Ic – FC relationships commonly used in current practice. Lastly, a rigorous analysis was performed for 25 selected locations of ground surveying measurements along the Avon River where ground slope conditions are mild (-1 to 2%) and channel heights range from about 2 – 4.5 m. The field data was divided into categories based on the observed distribution pattern of ground displacements including: large and distributed, moderate and distributed, small to negligible, and large and localized. A systematic approach was applied to determine potential critical layers contributing to the observed displacement patterns which led to the development of characteristic profiles for each category considered. The results of these analyses outline an alternative approach to the evaluation of lateral spreading in which a detailed geotechnical analysis is used to identify the potential for large spreading displacements and likely spatial distribution patterns of spreading. Key factors affecting the observed magnitude and distribution of spreading included the thickness of the critical layer, relative density, soil type and layer continuity. It was found that the large and distributed ground displacements were associated with a thick (1.5 – 2.5 m) deposit of loose, fine to silty sand (qc1 ~4-7 MPa, Ic 1.9-2.1, qc1n_cs ~50-70) that was continuous along the bank and with distance from the river. In contrast, small to negligible displacements were characterized by an absence of or relatively thin (< 1 m), discontinuous critical layer. Characteristic features of the moderate and distributed displacements were found to be somewhere between these two extremes. The localized and large displacements showed a characteristic critical layer similar to that observed in the large and distributed sites but that was not continuous and hence leading to the localized zone of displacement. The findings presented in this thesis illustrate the highly complex nature of lateral displacements that cannot be captured in simplified models but require a robust geotechnical analysis similar to that performed for this research.

Audio, Radio New Zealand

Questions to Ministers and lt;br / and gt; and lt;br / and gt; 1. Hon ANNETTE KING to the Prime Minister: Is he satisfied that all systems set up pursuant to commitments he has given to assist residents following the Christchurch earthquake are appropriate and working? and lt;br / and gt; and lt;br / and gt; 2. DAVID BENNETT to the Minister of Finance: What do this morning's Reserve Bank economic forecasts show? and lt;br / and gt; and lt;br / and gt; 3. Hon DAVID CUNLIFFE to the Minister of Finance: By what amount has the Reserve Bank lowered the official cash rate today, and what reason has the Bank given for this action? and lt;br / and gt; and lt;br / and gt; 4. GARETH HUGHES to the Minister of Finance: What will be the impact of the recent fuel price rise on the New Zealand economy, including impacts on GDP, consumer spending and the current account? and lt;br / and gt; and lt;br / and gt; 5. Hon DAVID PARKER to the Acting Minister for Economic Development: Has he been advised by the Prime Minister whether his appointment as Acting Minister for Economic Development is temporary or expected to carry on to the election? and lt;br / and gt; and lt;br / and gt; 6. KATRINA SHANKS to the Minister of Transport: What action is the Government taking to improve Wellington's train network? and lt;br / and gt; and lt;br / and gt; 7. Hon DAMIEN O'CONNOR to the Prime Minister: Can he assure the families of those killed in the Pike River Mine disaster that Government funding will be available for the recovery of bodies, given the mine is now in receiver's hands. and lt;br / and gt; and lt;br / and gt; 8. COLIN KING to the Minister of Civil Defence: Is the Government satisfied with the provision of replacement toilets for earthquake-affected Christchurch residents? and lt;br / and gt; and lt;br / and gt; 9. CAROL BEAUMONT to the Minister of Women's Affairs: Can she outline a significant improvement for women initiated by the current Government? and lt;br / and gt; and lt;br / and gt; 10. ALLAN PEACHEY to the Minister of Education: What provisions have been made to ensure continuity of early childhood education and schooling in the Christchurch region since the 22 February earthquake? and lt;br / and gt; and lt;br / and gt; 11. Hon TREVOR MALLARD to the Minister for Communications and Information Technology: What advice did he receive on any perceived conflict of interest before he took part in the Cabinet decision that led to the deferral of the requirement for MediaWorks to pay its frequency licence to the Crown? and lt;br / and gt; and lt;br / and gt; 12. KANWALJIT SINGH BAKSHI to the Minister of Internal Affairs: What reports has he received on the progress of urban search and rescue and firefighter teams working in Christchurch following the 22 February earthquake?

Research papers, University of Canterbury Library

The Canterbury earthquakes resulted in numerous changes to the waterways of Ōtautahi Christchurch. These included bank destabilisation, liquefaction effects, changes in bed levels, and associated effects on flow regimes and inundation levels. This study set out to determine if these effects had altered the location and pattern of sites utilised by īnanga (Galaxias maculatus) for spawning, which are typically restricted to very specific locations in upper estuarine areas. Extensive surveys were carried out in the Heathcote/Ōpāwaho and Avon/Ōtākaro catchments over the four peak months of the 2015 spawning season. New spawning sites were found in both rivers and analysis against pre-earthquake records identified that other significant changes have occurred. Major changes include the finding of many new spawning sites in the Heathcote/Ōpāwaho catchment. Sites now occur up to 1.5km further downstream than the previously reported limit and include the first records of spawning below the Woolston Cut. Spawning sites in the Avon/Ōtākaro catchment also occur in new locations. In the mainstem, sites now occur both upstream and downstream of all previously reported locations. A concentrated area of spawning was identified in Lake Kate Sheppard at a distinctly different location versus pre-quake records, and no spawning was found on the western shores. Spawning was also recorded for the first time in Anzac Creek, a nearby waterway connected to Lake Kate Sheppard via a series of culverts.

Research papers, University of Canterbury Library

The Mw 6.2 February 22nd 2011 Christchurch earthquake (and others in the 2010-2011 Canterbury sequence) provided a unique opportunity to study the devastating effects of earthquakes first-hand and learn from them for future engineering applications. All major events in the Canterbury earthquake sequence caused widespread liquefaction throughout Christchurch’s eastern suburbs, particularly extensive and severe during the February 22nd event. Along large stretches of the Avon River banks (and to a lesser extent along the Heathcote) significant lateral spreading occurred, affecting bridges and the infrastructure they support. The first stage of this research involved conducting detailed field reconnaissance to document liquefaction and lateral spreading-induced damage to several case study bridges along the Avon River. The case study bridges cover a range of ages and construction types but all are reinforced concrete structures which have relatively short, stiff decks. These factors combined led to a characteristic deformation mechanism involving deck-pinning and abutment back-rotation with consequent damage to the abutment piles and slumping of the approaches. The second stage of the research involved using pseudo-static analysis, a simplified seismic modelling tool, to analyse two of the bridges. An advantage of pseudo-static analysis over more complicated modelling methods is that it uses conventional geotechnical data in its inputs, such as SPT blowcount and CPT cone resistance and local friction. Pseudo-static analysis can also be applied without excessive computational power or specialised knowledge, yet it has been shown to capture the basic mechanisms of pile behaviour. Single pile and whole bridge models were constructed for each bridge, and both cyclic and lateral spreading phases of loading were investigated. Parametric studies were carried out which varied the values of key parameters to identify their influence on pile response, and computed displacements and damages were compared with observations made in the field. It was shown that pseudo-static analysis was able to capture the characteristic damage mechanisms observed in the field, however the treatment of key parameters affecting pile response is of primary importance. Recommendations were made concerning the treatment of these governing parameters controlling pile response. In this way the future application of pseudo-static analysis as a tool for analysing and designing bridge pile foundations in liquefying and laterally spreading soils is enhanced.