Following the 22 February 2011, MW 6.2 earthquake located on a fault beneath the Port Hills of Christchurch, fissuring of up to several hundred metres in length was observed in the loess and loess-colluvium of foot-slope positions in north-facing valleys of the Port Hills. The fissuring was observed in all major valleys, occurred at similar low altitudes, showing a contour-parallel orientation and often accompanied by both lateral compression/extension features and spring formation in the valley floor below. Fissuring locations studied in depth included Bowenvale Valley, Hillsborough Valley, Huntlywood Terrace–Lucas Lane, Bridle Path Road, and Maffeys Road–La Costa Lane. Investigations into loess soil, its properties and mannerisms, as well as international examples of its failure were undertaken, including study of the Loess Plateau of China, the Teton Dam, and palaeo-fissuring on Banks Peninsula. These investigations lead to the conclusion that loess has the propensity to fail, often due to the infiltration of water, the presence of which can lead to its instantaneous disaggregation. Literature study and laboratory analysis of Port Hills loess concluded that is has the ability to be stable in steep, sub-vertical escarpments, and often has a sub-vertically jointed internal structure and has a peak shear strength when dry. Values for cohesion, c (kPa) and the internal friction angle, ϕ (degrees) of Port Hills loess were established. The c values for the 40 Rapaki Road, 3 Glenview Terrace loess samples were 13.4 kPa and 19.7 kPa, respectively. The corresponding ϕ values were thought unusually high, at 42.0° and 43.4°.The analysed loess behaved very plastically, with little or no peak strength visible in the plots as the test went almost directly to residual strength. A geophysics resistivity survey showed an area of low resistivity which likely corresponds to a zone of saturated clayey loess/loess colluvium, indicating a high water table in the area. This is consistent with the appearances of local springs which are located towards the northern end of each distinct section of fissure trace and chemical analysis shows that they are sourced from the Port Hills volcanics. Port Hills fissuring may be sub-divided into three categories, Category A, Category B, and Category C, each characterised by distinctive features of the fissures. Category A includes fissures which display evidence of, spring formation, tunnel-gullying, and lateral spreading-like behaviour or quasi-toppling. These fissures are several metres down-slope of the loess-bedrock interface, and are in valleys containing a loess-colluvium fill. Category B fissures are in wider valleys than those in Category A, and the valleys contain estuarine silty sediments which liquefied during the earthquake. Category C fissures occurred at higher elevations than the fissures in the preceding categories, being almost coincident with bedrock outcropping. It is believed that the mechanism responsible for causing the fissuring is a complex combination of three mechanisms: the trampoline effect, bedrock fracturing, and lateral spreading. These three mechanisms can be applied in varying degrees to each of the fissuring sites in categories A, B, and C, in order to provide explanation for the observations made at each. Toppling failure can describe the soil movement as a consequence of the a three causative mechanisms, and provides insight into the movement of the loess. Intra-loess water coursing and tunnel gullying is thought to have encouraged and exacerbated the fissuring, while not being the driving force per se. Incipient landsliding is considered to be the least likely of the possible fissuring interpretations.
This paper discusses the seismic performance of the standard RC office building in Christchurch that is given as a structural design example in NZS3101, the concrete structures seismic standard in New Zealand. Firstly the push-over analysis was carried out to evaluate the lateral load carrying capacity of the RC building and then to compare that carrying capacity with the Japanese standard law. The estimated figures showed that the carrying capacity of the New Zealand standard RC office building of NZS3101:2006 was about one third of Japanese demanded carrying capacity. Secondly, time history analysis of the multi-mass system was performed to estimate the maximum response story drift angle using recorded ground motions. Finally, a three-dimensional analysis was carried out to estimate the response of the building to the 22nd February, 2011 Canterbury earthquake. The following outcomes were obtained. 1) The fundamental period of the example RC building is more than twice that of Japanese simplified calculation, 2) The example building’s maximum storey drift angle reached 2.5% under the recorded ground motions. The main purpose of this work is to provide background information of seismic design practice for the reconstruction of Christchurch.
A damaged brick building on Tuam Street. Bricks have fallen from the wall exposing the interior, where a wooden structure can be seen to have collapsed. The photographer comments, "This is the damage caused by the numerous earthquakes in Christchurch, New Zealand. It closely resembles a face and the round blob in the square hole at the top of the nose is a pigeon".
A video about several retail stores in Westfield Riccarton giving Christchurch women makeovers after the 22 February 2011 earthquake. Twenty-one women who were affected by the earthquakes or contributed to the recovery effort, were given a $1000 makeover by Blue Illusion, Rodney Wayne, Life Pharmacy, All About You, and Coffee Culture. The video includes an interview with Jude Kahui from Blue Illusion, who organised the makeovers. It also includes an interview with Shirley Quinn, one of the makeover recipients, as she receives her makeover.
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".
A residential street in New Brighton. Liquefaction still lines the street, and lampposts are leaning in different directions. The photographer comments, "This is the New Brighton red zone, which is parallel to the Avon River. The area suffered serious liquefaction during the numerous earthquakes/aftershocks and the land is being bought by the government. Although the houses do not look too bad in the background they have suffered badly. On the day I took this picture the council had just hours before cut the grass, which made the area look less abandoned".
A digitally manipulated photograph of the foyer of the Christchurch Art Gallery. The photographer comments, "The Christchurch art gallery has been closed to the public since the February 2011 earthquake and its reopening seems to be in the distant future. I want to convey the feeling that if art is not looked at darkness starts to overcome it and the paint starts to peel off".
The Avon and Heathcote Rivers, located in the city of Christchurch, New Zealand, are lowland spring-fed rivers linked with the Christchurch Groundwater System. At present, the flow paths and recharge sources to the Christchurch Groundwater System are not fully understood. Study of both the Avon and Heathcote Rivers can provide greater insight into this system. In addition, during the period 2010-2012, Christchurch has experienced large amounts of seismic activity, including a devastating Mw 6.2 aftershock on February 22nd, 2011, which caused widespread damage and loss of life. Associated with these earthquakes was the release of large amounts of water through liquefaction and temporary springs throughout the city. This provided a unique opportunity to study groundwater surface water interactions following a large scale seismic event. Presented herein is the first major geochemical study on the Avon and Heathcote Rivers and the hydrological impact of the February 22, 2011 Christchurch Earthquake. The Avon, Heathcote, and Waimakariri Rivers were sampled in quarterly periods starting in July 2011 and analyzed for stable Isotopes δ¹⁸O, δD, and δ¹³C and major anion composition. In addition, post -earthquake samples were collected over the days immediately following the February 22, 2011 earthquake and analyzed for stable isotopes δ¹⁸O and δD and major anion composition. A variety of analytical methods were used identify the source of the waters in the Avon-Heathcote System and evaluate the effectiveness of stable isotopes as geochemical tracers in the Christchurch Groundwater System. The results of this thesis found that the waters from the Avon and Heathcote Rivers are geochemically the same, originating from groundwater, and exhibit a strong tidal influence within 5km of the Avon-Heathcote Estuary. The surface waters released following the February 22nd, 2011 earthquake were indistinguishable from quarterly samples taken from the Avon and Heathcote Rivers when comparing stable isotopic composition. The anion data suggests the waters released following the February 22nd, 2011 Christchurch Earthquake were sourced primarily from shallow groundwater, and also suggests a presence of urban sewage at some sites. Attempts to estimate recharge sources for the Avon-Heathcote Rivers using published models for the Christchurch Groundwater System yielded results that were not consistent between models. In evaluating the use of geochemical constituents as tracers in the Christchurch Groundwater System, no one isotope could provide a clear resolution, but when used in conjunction, δ¹⁸O, δ¹³C, and DIC, seem to be the most effective tracers. Sample sizes for δ¹³C were too small for a robust evaluation. Variability on the Waimakariri River appears to be greater than previously estimated, which could have significant impacts on geochemical models for the Christchurch Groundwater System. This research demonstrates the value of using multiple geochemical constituents to enrich our understanding of the groundwater surfaces-water interactions and the Christchurch Groundwater System as a whole.
A video about people buying marmite from the Fresh Choice supermarket in Merivale. The supermarket has a secret stash of marmite which they have made available to customers in exchange for a bank note. The bank notes will be donated to the Christchurch Women's Refuge. Marmite went missing from supermarket shelves across the country after the 22 February 2011 earthquake damaged the factory in Christchurch.
Workers operate a drilling rig, sampling soil as part of EQC's geotechnical investigation of TC3 land. The photographer comments, "The work of getting 'soil' samples from all the areas marked as green/blue zones in Christchurch. These areas may be susceptible to liquefaction if a major earthquake occurs. The soil samples were a failure as all they found was sand".
A building on St Asaph Street has been demolished, exposing the interior structure of the adjoining building. The photographer comments, "The building that this one was part of has been demolished and the join looks very much like the exterior walls of an Anglo-Saxon house. It has been exposed due to the demolition of damaged buildings after the Christchurch earthquake".
The 4 September, 22 February, and 13 June earthquakes experienced in Canterbury, New Zealand would have been significant events individually. Together they present a complex and unprecedented challenge for Canterbury and New Zealand. The repetitive and protracted nature of these events has caused widespread building and infrastructure damage, strained organisations’ financial and human resources and challenged insurer and investor confidence. The impact of the earthquakes was even more damaging coming in the wake of the worst worldwide recession since the great depression of the 1930s. However, where there is disruption there is also opportunity. Businesses and other organisations will drive the physical, economic and social recovery of Canterbury, which will be a dynamic and long-term undertaking. Ongoing monitoring of the impacts, challenges and developments during the recovery is critical to maintaining momentum and making effective mid-course adjustments. This report provides a synthesis of research carried out by the Resilient Organisations (ResOrgs) Research Programme1 at the University of Canterbury and Recover Canterbury in collaboration with Opus Central Laboratories (part of Opus International Consultants). The report includes discussions on the general state of the economy as well as data from three surveys (two conducted by ResOrgs and one by Recover Canterbury) on business impacts of the earthquakes, population movements and related economic recovery issues. This research and report offers two primary benefits:
As part of the ‘Project Masonry’ Recovery Project funded by the New Zealand Natural Hazards Research Platform, commencing in March 2011, an international team of researchers was deployed to document and interpret the observed earthquake damage to masonry buildings and to churches as a result of the 22nd February 2011 Christchurch earthquake. The study focused on investigating commonly encountered failure patterns and collapse mechanisms. A brief summary of activities undertaken is presented, detailing the observations that were made on the performance of and the deficiencies that contributed to the damage to approximately 650 inspected unreinforced clay brick masonry (URM) buildings, to 90 unreinforced stone masonry buildings, to 342 reinforced concrete masonry (RCM) buildings, to 112 churches in the Canterbury region, and to just under 1100 residential dwellings having external masonry veneer cladding. Also, details are provided of retrofit techniques that were implemented within relevant Christchurch URM buildings prior to the 22nd February earthquake. In addition to presenting a summary of Project Masonry, the broader research activity at the University of Auckland pertaining to the seismic assessment and improvement of unreinforced masonry buildings is outlined. The purpose of this outline is to provide an overview and bibliography of published literature and to communicate on-going research activity that has not yet been reported in a complete form. http://sesoc.org.nz/conference/programme.pdf
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.
The northern side of the Christ Church Cathedral with the cafe and store in the foreground. Shipping containers have been placed around the eastern side of the Cathedral to protect the road from falling debris. Wire fencing has also been placed around the building as a cordon. To the right, the damaged and party deconstructed tower can be seen with the missing spire which fell during the 22 February 2011 earthquake.
A video about the Christchurch City Council housing complex on Conference Street in the Christchurch central city. The housing complex was unoccupied after the 22 February 2011 earthquake despite the housing shortage. Christchurch City Council said that the vacant units could not be lived in because of structural damage or damage to services. However, the building has been checked by structural engineers and many of the rooms have been deemed safe to occupy.
A video of a tour of the historic Canterbury Club building on Cambridge Terrace. The club will reopen on 9 June 2012, after an intensive rebuild and restoration process which has fixed the damage from the 22 February 2011 earthquake. The video also includes an interview with Dr Brent Stanley, the Canterbury Club President. Stanley talks about the strengthening work that was done in 2009, as well as the history of the club.
Our Christchurch correspondent, Katy Gosset takes us on a musical journey with the help of one of the city's longest serving pianists. For 23 years Peter Lewis played the piano in the Crowne Plaza Hotel before being made redundant by the February 2011 earthquake. Peter has since struggled to find a way to share his music with others. Today Katy seeks out some city pianos and takes him on a mystery tour to rediscover the pleasure of playing.
The Christchurch earthquake sequence has been on-going since September 4th 2010. The largest two earthquakes, magnitude (M) 7.1 on September 4th and the M 6.3 on February 22nd 2011 caused immediate and significant damage to the city of Christchurch. As a consequence of the earthquakes, the tourism sector in the Canterbury region has been heavily impacted, with broader impacts being felt throughout the South Island. Resilient Organisations and the University of Canterbury began a series of quantitative investigations into the recovery and response of key business sectors to the earthquakes. The purpose of this study was to build on this work by exploring the outcomes of the earthquakes on the tourism sector, a critical economic driver in the region. Two postal surveys were sent to 719 tourism business managers; the first to businesses in the ‘Impact Zone’ defined as areas that experienced Modified Mercalli intensities greater than 6. The second survey was sent to the remaining businesses throughout the Canterbury region (‘Rest of Canterbury’). Response rates were 46% response for the Impact Zone, and 29% for the Rest of Canterbury. Key findings:
Though there is a broad consensus that communities play a key role in disaster response and recovery, most of the existing work in this area focuses on the activities of donor agencies, formal civil defence authorities, and local/central government. Consequently, there is a paucity of research addressing the on-going actions and activities undertaken by communities and ‘emergent groups’ , particularly as they develop after the immediate civil defence or ‘response’ phase is over. In an attempt to address this gap, this inventory of community-led recovery initiatives was undertaken approximately one year after the most devastating February 2011 earthquake. It is part of on-going project at Lincoln University documenting – and seeking a better understanding of - various emergent communities’ roles in recovery, their challenges, and strategies for overcoming them. This larger project also seeks to better understand how collaborative work between informal and formal recovery efforts might be facilitated at different stages of the process. This inventory was conducted over the December 2011 – February 2012 period and builds on Landcare Research’s Christchurch Earthquake Activity Inventory which was a similar snapshot taken in April 2011. The intention behind conducting this updated inventory is to gain a longitudinal perspective of how community-led recovery activities evolve over time. Each entry is ordered alphabetically and contact details have been provided where possible. A series of keywords have also been assigned that describe the main attributes of each activity to assist searches within this document.This inventory was supported by the Lincoln University Research Fund and the Royal Society Marsden Fund.
A video about the reopening of the city branch of the Punting on the Avon route, which has been closed since the 22 February 2011 earthquake. The video includes an interview with Mayor Bob Parker about tourism in Christchurch. He mentions that Australia has updated its travel advisory on Christchurch to say that it is as safe as the other cities in New Zealand. The video also includes footage of Parker poling a punt.
The devastating earthquakes of September 2010 and February 2011 have without question upset the Christchurch City way of life for all. Families and businesses, as well as the natural and built environments have been directly affected, and our social landscapes have since evolved to accommodate the visible changes. Though not perhaps seen as a priority, the Christchurch nightlife has been profoundly altered by the quakes and the once popular CBD clubbing scene has ceased to exist. The concern highlighted in this article is the way in which this has put pressure on suburban bars and the the implications of this for local residents.
A video of an interview with Jenny Beecroft and Warren Beecroft about the housing shortage in Christchurch. Jenny's daughter Selena Beecroft had to move into Jenny's house with her two sons after the 22 February 2011 earthquake damaged her rental property. Selena has epilepsy and can only move into a rental property in walking distance of her work and her children's school. The family is one of many living in difficult situations despite the government's claim that there is no housing crisis in Christchurch.
Large cracks run through the brick cladding of this house in Wainoni. The photographer comments, "During the numerous earthquakes in Christchurch the land which ran alongside the Avon river on Avonside Drive slumped towards the waterway. Houses which were wooden framed and had an external brick veneer started to sink into the liquefied soil. This caused the brick walls to crack, but the houses' occupants though shook up were saved by the wooden framework from the houses collapsing on them".
On the second day of teaching for 2011, the University of Canterbury (UC) faced the most significant crisis of its 138-year history. After being shaken severely by a magnitude 7.1 earthquake on 4 September 2010, UC felt it was well along the pathway to getting back to ‘normal’. That all changed at 12:51pm on 22 February 2011, when Christchurch city was hit by an even more devastating event. A magnitude 6.3 (Modified Mercalli intensity ten – MM X) earthquake, just 13km south-east of the Christchurch city centre, caused vertical peak ground accelerations amongst the highest ever recorded in an urban environment, in some places more than twice the acceleration due to gravity. The earthquake caused immediate evacuation of the UC campus and resulted in significant damage to many buildings. Thankfully there were no serious injuries or fatalities on campus, but 185 people died in the city and many more suffered serious injuries. At the time of writing, eighteen months after the first earthquake in September, Christchurch is still experiencing regular earthquakes. Seismologists warn that the region may experience heightened seismicity for a decade or more. While writing this report we have talked with many different people from across the University. People’s experiences are different and we have not managed to talk with everyone, but we hope that by drawing together many different perspectives from across the campus that this report will serve two purposes; to retain our institutional memory of what we have learnt over the past eighteen months, and also to share our learnings with other organisations in New Zealand and around the world who, we hope, will benefit from learning about our experience.
Digitally manipulated image of graffiti on a brick building on St Asaph Street. The graffiti depicts a sticking plaster over a broken section of the wall, with the words "I'll kiss it better". The photographer comments, "After the 22 February 2011 earthquake in Christchurch band aid plasters starting to appear in different parts of the city on damaged buildings. A year later most can still be seen. This one was once a whole plaster, but it has slowly broken up where it crossed the gap. The red bricks seen to symbolise the terrible wounds caused to the City and it's people".
This paper shows an understanding of the availability of resources in post-disaster reconstruction and recovery in Christchurch, New Zealand following its September 4, 2010 and February 22, 2011 earthquakes. Overseas experience in recovery demonstrates how delays and additional costs may incur if the availability of resources is not aligned with the reconstruction needs. In the case of reconstruction following Christchurch earthquakes, access to normal resource levels will be insufficient. An on-line questionnaire survey, combined with in-depth interviews was used to collect data from the construction professionals that had been participated in the post-earthquake reconstruction. The study identified the resources that are subject to short supply and resourcing challenges that are currently faced by the construction industry. There was a varied degree of impacts felt by the surveyed organisations from resource shortages. Resource pressures were primarily concentrated on human resources associated with structural, architectural and land issues. The challenges that may continue playing out in the longer-term reconstruction of Christchurch include limited capacity of the construction industry, competition for skills among residential, infrastructure and commercial sectors, and uncertainties with respect to decision making. Findings provide implications informing the ongoing recovery and rebuild in New Zealand. http://www.iiirr.ucalgary.ca/Conference-2012
The magnitude Mw 6.2 earthquake of February 22nd 2011 that struck beneath the city of Christchurch, New Zealand, caused widespread damage and was particularly destructive to the Central Business District (CBD). The shaking caused major damage, including collapses of structures, and initiated ground failure in the form of soil liquefaction and consequent effects such as sand boils, surface flooding, large differential settlements of buildings and lateral spreading of ground towards rivers were observed. A research project underway at the University of Canterbury to characterise the engineering behaviour of the soils in the region was influenced by this event to focus on the performance of the highly variable ground conditions in the CBD. This paper outlines the methodology of this research to characterise the key soil horizons that underlie the CBD that influenced the performance of important structures during the recent earthquakes, and will influence the performance of the rebuilt city centre under future events. The methodology follows post-earthquake reconnaissance in the central city, a desk study on ground conditions, site selection, mobilisation of a post-earthquake ground investigation incorporating the cone penetration test (CPT), borehole drilling, shear wave velocity profiling and Gel-push sampling followed by a programme of laboratory testing including monotonic and cyclic testing of the soils obtained in the investigation. The research is timely and aims to inform the impending rebuild, with appropriate information on the soils response to dynamic loading, and the influence this has on the performance of structures with various foundation forms.
During the Christchurch earthquake of February 2011, several midrise buildings of Reinforced Concrete Masonry (RCM) construction achieved performance levels in the range of life safety to near collapse levels. These buildings were subjected to seismic demands higher than the building code requirements of the time and higher than the current New Zealand Loadings Standard (NZS-1170.5:2004). Structural damage to these buildings has been documented and is currently being studied to establish lessons to be learned from their performance and how to incorporate these lessons into future RCM design and construction practices. This paper presents a case study of a six story RCM building deemed to have reached the near collapse performance level. The RCM walls on the 2nd floor failed due to toe crushing reducing the building’s lateral resistance in the east-west direction. A nonlinear dynamic analysis on a 3D model was conducted to simulate the development of the governing failure mechanism. Preliminary analysis results show that the damaged walls were initially under large compression forces from gravity loads which caused increase in their lateral strength and reduced their ductility. After toe crushing failure developed, axial instability of the model was prevented by a redistribution of gravity loads.
A digitally manipulated image of printer's type, spelling out "Safe Dust". The photographer comments, "After the September 2010 Christchurch earthquake liquefaction poured out of the ground mostly in the East of Christchurch. This silt, which was a form of sand was declared safe and would not harm gardens if it was spread around in moderation. After the February 2011 quake as a result of even more liquefaction and the sewers being ruptured, the liquefaction was declared as toxic. People clearing it up should wear a mask, boots and gloves especially when it had dried up and become dusty. This just so happens to be the words found on an old printing press".