Road damage and liquefaction in a residential street. The photographer comments, "A great gouge in the road caused by liquefaction undermining the road surface and a car driving over it. This was the earthquake in Christchurch, New Zealand on 22 February 2011".
A photograph of Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, sitting among the damaged parts of the Townsend Telescope. The telescope was damaged during the 22 February 2011 earthquake, when the Observatory tower at the Christchurch Arts Centre collapsed. Kershaw has been given the task of restoring the telescope. In this photograph he is holding the telescope's clock drive.
A photograph of Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, sitting among the damaged parts of the Townsend Telescope. The telescope was damaged during the 22 February 2011 earthquake, when the Observatory tower at the Christchurch Arts Centre collapsed. Kershaw has been given the task of restoring the telescope. In this photograph he is holding the telescope's clock drive.
A photograph of Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, sitting among the damaged parts of the Townsend Telescope. The telescope was damaged during the 22 February 2011 earthquake, when the Observatory tower at the Christchurch Arts Centre collapsed. Kershaw has been given the task of restoring the telescope. In this photograph he is holding the telescope's clock drive.
A photograph of Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, sitting among the damaged parts of the Townsend Telescope. The telescope was damaged during the 22 February 2011 earthquake, when the Observatory tower at the Christchurch Arts Centre collapsed. Kershaw has been given the task of restoring the telescope. In this photograph he is holding the telescope's clock drive.
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.
Glass panels with brass surrounds, stacked inside a building. The photographer comments, "These were brass dividers that were brought inside the building two years ago after the Christchurch earthquake. They have been sitting there abandoned in a restaurant that will be either repaired and reopened at a later date or demolished like the many others of its kind".
The urban environment influences the way people live and shape their everyday lives, and microclimate sensitive design can enhance the use of urban streets and public spaces. Innovative approaches to urban microclimate design will become more important as the world’s population becomes ever more urban, and climate change generates more variability and extremes in urban microclimatic conditions. However, established methods of investigation based upon conventions drawn from building services research and framed by physiological concepts of thermal comfort may fail to capture the social dynamics of urban activity and their interrelationship with microclimate. This research investigates the relationship between microclimate and urban culture in Christchurch, New Zealand, based upon the concept of urban comfort. Urban comfort is defined as the socio-cultural (therefore collective) adaptation to microclimate due to satisfaction with the urban environment. It involves consideration of a combination of human thermal comfort requirements and adaptive comfort circumstances, preferences and strategies. A main methodological challenge was to investigate urban comfort in a city undergoing rapid physical change following a series of major earthquakes (2010-2011), and that also has a strongly seasonal climate which accentuates microclimatic variability. The field investigation had to be suitable for rapidly changing settings as buildings were demolished and rebuilt, and be able to capture data relevant to a cycle of seasons. These local circumstances meant that Christchurch was valuable as an example of a city facing rapid and unpredictable change. An interpretive, integrative, and adaptive research strategy that combined qualitative social science methods with biophysical measures was adopted. The results are based upon participant observation, 86 in-depth interviews with Christchurch residents, and microclimate data measurements. The interviews were carried out in a variety of urban settings including established urban settings (places sustaining relatively little damage) and emerging urban settings (those requiring rebuilding) during 2011-2013. Results of this research show that urban comfort depends on adaptive strategies which in turn depend on culture. Adaptive strategies identified through the data analysis show a strong connection between natural and built landscapes, combined with the regional outdoor culture, the Garden City identity and the connections between rural and urban landscapes. The results also highlight that thermal comfort is an important but insufficient indicator of good microclimate design, as social and cultural values are important influences on climate experience and adaptation. Interpretive research is needed to fully understand urban comfort and to provide urban microclimate design solutions to enhance the use of public open spaces in cities undergoing change.
One landscape colour digital photograph taken on 11 May 2011 showing part of the window of Lyttelton Sea Foods on London Street. A handwritten sign taped to the window apologises for the shop's closure. The Restricted Use (yellow) placard is also taped to the window. With many of the commercial buildings in Lyttelton damaged or demolished, busi...
One landscape colour digital photograph taken on 13 May 2011 showing the damage to the Gaol Steps between Oxford and St Davids Streets and the upper playground of Lyttelton Main School. The Gaol Steps are a pedestrian link between Oxford and St Davids Streets. In October 2013 these steps were closed and barricaded with temporary fencing because...
Gerry Brownlee is the Canterbury Earthquake Recovery Minister. Hugo Kristinsson is a South Brighton resident who stood for mayor last year on the issue of flood risk and land damage. David Stringer is the spokesperson for the community lobby group Insurance Watch - which has been seeking answers from the council since 2011 about the flood risk to the city. Nine to Noon speaks with all three about the recent flooding in Christchurch.
Photograph captioned by Fairfax, "Members of the Red Cross civil defence response team and South Canterbury Police have been in Christchurch helping with the earthquake clean up. Welfare checks required the team to walk along River Road checking on householders. Pictured looking at a damaged bridge on River Road near Tai Tapu are (from left) Andy Todd, Anna Munro and Ken Weavers".
Businesses in the Christchurch suburb of New Brighton are demanding urgent action to pull the area out of an economic slump. The seaside town has struggled since the Canterbury Earthquakes, with thousands of people - and customers - leaving the area due to land damage under their homes.
It's no longer politics as usual in Christchurch following a series of devastating earthquakes. Not everyone in the city and its surrounding areas is happy with last week's offer to buy out those households on land which has suffered the worst damage. Our political editor Brent Edwards investigates.
For the first time in November 2011, Christchurch residents finally had the opportunity to see the earthquake-damaged city centre on the Red Zone bus tours organised by CERA. The podium which formerly held the Godley statue. Behind is the Regent Theatre dome which has been removed from the building.
Six years on from the Christchurch earthquakes, one in five residents of the city say the disaster is still taking its toll. The latest wellbeing survey by the Canterbury DHB found people living in north-east and east Christchurch were the most likely to be suffering from issues such as anxiety, from ongoing aftershocks, being in a damaged environment, and surrounded by construction.
The Canterbury earthquake sequence in New Zealand’s South Island induced widespread liquefaction phenomena across the Christchurch urban area on four occasions (4 Sept 2010; 22 Feb; 13 June; 23 Dec 2011), that resulted in widespread ejection of silt and fine sand. This impacted transport networks as well as infiltrated and contaminated the damaged storm water system, making rapid clean-up an immediate post-earthquake priority. In some places the ejecta was contaminated by raw sewage and was readily remobilised in dry windy conditions, creating a long-term health risk to the population. Thousands of residential properties were inundated with liquefaction ejecta, however residents typically lacked the capacity (time or resources) to clean-up without external assistance. The liquefaction silt clean-up response was co-ordinated by the Christchurch City Council and executed by a network of contractors and volunteer groups, including the ‘Farmy-Army’ and the ‘Student-Army’. The duration of clean-up time of residential properties and the road network was approximately 2 months for each of the 3 main liquefaction inducing earthquakes; despite each event producing different volumes of ejecta. Preliminary cost estimates indicate total clean-up costs will be over NZ$25 million. Over 500,000 tonnes of ejecta has been stockpiled at Burwood landfill since the beginning of the Canterbury earthquakes sequence. The liquefaction clean-up experience in Christchurch following the 2010-2011 earthquake sequence has emerged as a valuable case study to support further analysis and research on the coordination, management and costs of large volume deposition of fine grained sediment in urban areas.
By closely examining the performance of a 22-storey steel framed building in Christchurch subject to various earthquakes over the past seven years, it is shown that a number of lessons can be learnt regarding the cost-effective consideration of non-structural elements. The first point in this work is that non-structural elements significantly affected the costs associated with repairing steel eccentrically braced frame (EBF) links. The decommissioning or rerouting of non-structural elements in the vicinity of damaged links in the case study building attributed to approximately half the total cost of their repair. Such costs could be significantly reduced if the original positioning of non-structural elements took account of the potential need to repair the EBF links. The second point highlighted is the role that pre-cast cladding apparently played on the distribution and type of damage in the building. Loss estimates obtained following the FEMA P-58 framework vary considerably when cladding is or isnt modelled, both because of changes to drift demands up the height of the building and because certain types of subsequent damage are likely to be cheaper to repair than others. Finally, costly repairs to non-structural partition walls were required not only after the moment magnitude 7.1 earthquake in 2010 but also in multiple aftershocks in the years that followed. Repair costs associated with aftershock events exceeded those from the main event, emphasizing the need to consider aftershocks within modern performance-based earthquake engineering and also the opportunity that exists to make more cost-effective repair strategies following damaging earthquakes.
Following the Mw 6.2 Christchurch Earthquake on 22 February 2011, extensive ground cracking in loessial soils was reported in some areas of the Port Hills, southeast of central Christchurch. This study was undertaken to investigate the mechanisms of earthquake-induced ground damage on the eastern side of the Hillsborough Valley. A zone of extensional cracking up to 40m wide and 600m long was identified along the eastern foot-slope, accompanied by compression features and spring formation at the toe of the slope. An engineering geological and geomorphological model was developed for the eastern Hillsborough Valley that incorporates geotechnical investigation data sourced from the Canterbury Geotechnical Database (CGD), the findings of trenching and seismic refraction surveying carried out for this research, and interpretation of historical aerial photographs. The thickness and extent of a buried peat swamp at the base of the slope was mapped, and found to coincide with significant compression features. Ground cracking was found to have occurred entirely within loess-colluvium and to follow the apices of pre-1920s tunnel-gully fan debris at the southern end of the valley. The ground-cracking on the eastern side of the Hillsborough Valley is interpreted to have formed through tensile failure of the loess-colluvium. Testing was carried out to determine the tensile strength of Port Hills loess colluvium as a function of water content and density, in order to better understand the occurrence and distribution of the observed ground cracking. A comprehensive review of the soil tensile strength testing literature was undertaken, from which a test methodology was developed. Results show remoulded loess-colluvium to possess tensile strength of 7 - 28 kPa across the range of tested moisture contents (10-15%) and dry densities (1650-1900kg/m3). A positive linear relationship was observed between tensile strength and dry density, and a negative linear relationship between moisture content and tensile strength. The observed ground damage and available geotechnical information (inclinometer and piezometer records provided by the Earthquake Commission) were together used to interpret the mechanism(s) of slope movement that occurred in the eastern Hillsborough Valley. The observed ground damage is characteristic of translational movement, but without the development of lateral release scarps, or a basal sliding surface - which was not located during drilling. It is hypothesised that shear displacement has been accommodated by multiple slip surfaces of limited extent within the upper 10m of the slope. Movement has likely occurred within near-saturated colluvial units that have lost strength during earthquake shaking. The eastern Hillsborough Valley is considered to be an ‘incipient translational slide’, as both the patterns of damage and shearing are consistent with the early stages of such slide development. Sliding block analysis was utilised to understand how the eastern Hillsborough Valley may perform in a future large magnitude earthquake. Known cumulative displacements of ~0.3m for eastern Hillsborough Valley during the 2010-2011 Canterbury Earthquake Sequence were compared with modelled slope displacements to back-analyse a lower-bound yield acceleration of 0.2 - 0.25g. Synthetic broadband modelling for future Alpine and Hope Fault earthquakes indicates PGAs of approximately 0.08g for soil sites in the Christchurch area, as such, slope movement is unlikely to be reactivated by an Alpine Fault or Hope Fault earthquake. This does not take into account the possible role of strength loss due to excess pore pressure that may occur during these future events.
The paper proposes a simple method for quick post-earthquake assessment of damage and condition of a stock of bridges in a transportation network using seismic data recorded by a strong motion array. The first part of the paper is concerned with using existing free field strong motion recorders to predict peak ground acceleration (PGA) at an arbitrary bridge site. Two methods are developed using artificial neural networks (a single network and a committee of neural networks) considering influential parameters, such as seismic magnitude, hypocentral depth and epicentral distance. The efficiency of the proposed method is explored using actual strong motion records from the devastating 2010 Darfield and 2011 Christchurch earthquakes in New Zealand. In the second part, two simple ideas are outlined how to infer the likely damage to a bridge using either the predicted PGA and seismic design spectrum, or a broader set of seismic metrics, structural parameters and damage indices.
Rapid, reliable information on earthquake-affected structures' current damage/health conditions and predicting what would happen to these structures under future seismic events play a vital role in accelerating post-event evaluations, leading to optimized on-time decisions. Such rapid and informative post-event evaluations are crucial for earthquake-prone areas, where each earthquake can potentially trigger a series of significant aftershocks, endangering the community's health and wealth by further damaging the already-affected structures. Such reliable post-earthquake evaluations can provide information to decide whether an affected structure is safe to stay in operation, thus saving many lives. Furthermore, they can lead to more optimal recovery plans, thus saving costs and time. The inherent deficiency of visual-based post-earthquake evaluations and the importance of structural health monitoring (SHM) methods and SHM instrumentation have been highlighted within this thesis, using two earthquake-affected structures in New Zealand: 1) the Canterbury Television (CTV) building, Christchurch; 2) the Bank of New Zealand (BNZ) building, Wellington. For the first time, this thesis verifies the theoretically- and experimentally validated hysteresis loop analysis (HLA) SHM method for the real-world instrumented structure of the BNZ building, which was damaged severely due to three earthquakes. Results indicate the HLA-SHM method can accurately estimate elastic stiffness degradation for this reinforced concrete (RC) pinched structure across the three earthquakes, which remained unseen until after the third seismic event. Furthermore, the HLA results help investigate the pinching effects on the BNZ building's seismic response. This thesis introduces a novel digital clone modelling method based on the robust and accurate SHM results delivered by the HLA method for physical parameters of the monitored structure and basis functions predicting the changes of these physical parameters due to future earthquake excitations. Contrary to artificial intelligence (AI) based predictive methods with black-box designs, the proposed predictive method is entirely mechanics-based with an explicitly-understandable design, making them more trusted and explicable to stakeholders engaging in post-earthquake evaluations, such as building owners and insurance firms. The proposed digital clone modelling framework is validated using the BNZ building and an experimental RC test structure damaged severely due to three successive shake-table excitations. In both structures, structural damage intensifies the pinching effects in hysteresis responses. Results show the basis functions identified from the HLA-SHM results for both structures under Event 1 can online estimate structural damage due to subsequent Events 2-3 from the measured structural responses, making them valuable tool for rapid warning systems. Moreover, the digital twins derived for these two structures under Event 1 can successfully predict structural responses and damage under Events 2-3, which can be integrated with the incremental dynamic analysis (IDA) method to assess structural collapse and its financial risks. Furthermore, it enables multi-step IDA to evaluate earthquake series' impacts on structures. Overall, this thesis develops an efficient method for providing reliable information on earthquake-affected structures' current and future status during or immediately after an earthquake, considerably guaranteeing safety. Significant validation is implemented against both experimental and real data of RC structures, which thus clearly indicate the accurate predictive performance of this HLA-based method.
The old (or is that the new) Inland Revenue Department (IRD) building on the corner of Madras and Cashel Streets in central Christchurch. Built in 2006/07 on the site of the former Farmers department store (itself badly damaged by fire), it was just a few years old when the earthquake of February 2011 struck, and subsequent quakes (all through 2...
Reinforced concrete buildings that satisfied modern seismic design criteria generally behaved as expected during the recent Canterbury and Kaikoura earthquakes in New Zealand, forming plastic hinges in intended locations. While this meant that life-safety performance objectives were met, widespread demolition and heavy economic losses took place in the aftermath of the earthquakes.The Christchurch central business district was particularly hard hit, with over 60% of the multistorey reinforced concrete buildings being demolished. A lack of knowledge on the post-earthquake residual capacity of reinforced concrete buildings was a contributing factor to the mass demolition.Many aspects related to the assessment of earthquake-damaged reinforced concrete buildings require further research. This thesis focusses on improving the state of knowledge on the post earthquakeresidual capacity and reparability of moderately damaged plastic hinges, with an emphasis on plastic hinges typical of modern moment frame structures. The repair method focussed on is epoxy injection of cracks and patching of spalled concrete. A targeted test program on seventeen nominally identical large-scale ductile reinforced concrete beams, three of which were repaired by epoxy injection following initial damaging loadings, was conducted to support these objectives. Test variables included the loading protocol, the loading rate, and the level of restraint to axial elongation.The information that can be gleaned from post-earthquake damage surveys is investigated. It is shown that residual crack widths are dependent on residual deformations, and are not necessarily indicative of the maximum rotation demands or the plastic hinge residual capacity. The implications of various other types of damage typical of beam and column plastic hinges are also discussed.Experimental data are used to demonstrate that the strength and deformation capacity of plastic hinges with modern seismic detailing are often unreduced as a result of moderate earthquake induced damage, albeit with certain exceptions. Special attention is given to the effects of prior yielding of the longitudinal reinforcement, accounting for the low-cycle fatigue and strain ageing phenomena. A material-level testing program on the low-cycle fatigue behaviour of grade 300E reinforcing steel was conducted to supplement the data available in the literature.A reduction in stiffness, relative to the initial secant stiffness to yield, occurs due to moderate plastic hinging damage. This reduction in stiffness is shown to be correlated with the ductility demand,and a proposed model gives a conservative lower-bound estimate of the residual stiffness following an arbitrary earthquake-type loading. Repair by epoxy injection is shown to be effective in restoring the majority of stiffness to plastic hinges in beams. Epoxy injection is also shown to have implications for the residual strength and elongation characteristics of repaired plastic hinges.
The Forsyth Barr building has stood silent and empty (except the occasional intruder and pigeons) since the February 2011 earthquake. It was sold "as is" and I understand that it is now going to be fitted out as a hotel. This is the building that had severe stairwell damage during the quake necessitating people being lowered via ropes etc on t...
A photograph of the earthquake-damaged Canterbury Provincial Chambers on Durham Street. The roof and upper walls of the Stone Chamber have collapsed, the masonry falling onto the footpath below. The building has been cordoned off with wire fencing.
A photograph of the earthquake-damaged Canterbury Provincial Chambers on Durham Street. The roof and upper walls of the Stone Chamber have collapsed, the masonry falling onto the footpath below. The building has been cordoned off with wire fencing.
Some of Christchurch's earthquake damaged red-zone land is another step closer to having some long term decisions made about its future. Today the Minister of Greater Christchurch Regeneration, Megan Woods, formally handed over ownership of 70 hectares of land to the Christchurch City Council. The land gifted to the council is in the coastal suburbs of Southshore, South Brighton and Brooklands, where residents have been waiting almost a decade to find out what the future holds for their area. Rachel Graham reports
From the time it opened in the 1920s, the Winter Garden ballroom was the place to go for debutante balls and big-band concerts in Christchurch. Queen Elizabeth II even dined there during her visit in 1954. But this special part of Christchurch's history is over and the Armagh Street building has been placed on the urgent demolition list because of earthquake damage. Tiny Kirk is the chairman of the Trade Union Centre which has owned the building since 1984.
The earthquake sequence has resulted in significant physical and reputational damage to the Canterbury tourism industry. Eighteen months after the earthquakes inbound tourism data is still below pre-earthquake levels, with Canterbury operators reporting that the industry has not bounced back to where it was before September 2010. Outcomes of the earthquakes on business performance highlight there were winners and losers in the aftermath. Recovery of inbound tourism markets is closely tied to the timeframe to rebuild the CBD of Christchurch. Reinstating critical tourism infrastructure will drive future tourism investment, and allow tourism businesses to regenerate and thrive into the future. A blueprint for rebuilding the CBD of Christchurch was released by the Christchurch City Council in July 2012, and has been well received by tourism stakeholders in the region. The challenge now is for city officials to fund the development projects outlined in the blueprint, and to rebuild the CBD as quickly as possible in order to help regenerate the tourism industry in Christchurch, Canterbury and the rest of the South Island
Businesses in the Christchurch suburb of New Brighton say something needs to be done urgently to pull the area out of an economic slump. The seaside town has struggled since the Canterbury Earthquakes, with thousands of people - and customers - leaving the area due to land damage under their homes. And they're pointing the fingers at city leaders like the Christchurch City Council and its rebuild agency, Development Christchurch. Logan Church spoke to New Brighton business owner Nigel Gilmore.