A city’s planted trees, the great majority of which are in private gardens, play a fundamental role in shaping a city’s wild ecology, ecosystem functioning, and ecosystem services. However, studying tree diversity across a city’s many thousands of separate private gardens is logistically challenging. After the disastrous 2010–2011 earthquakes in Christchurch, New Zealand, over 7,000 homes were abandoned and a botanical survey of these gardens was contracted by the Government’s Canterbury Earthquake Recovery Authority (CERA) prior to buildings being demolished. This unprecedented access to private gardens across the 443.9 hectares ‘Residential Red Zone’ area of eastern Christchurch is a unique opportunity to explore the composition of trees in private gardens across a large area of a New Zealand city. We analysed these survey data to describe the effects of housing age, socio-economics, human population density, and general soil quality, on tree abundance, species richness, and the proportion of indigenous and exotic species. We found that while most of the tree species were exotic, about half of the individual trees were local native species. There is an increasing realisation of the native tree species values among Christchurch citizens and gardens in more recent areas of housing had a higher proportion of smaller/younger native trees. However, the same sites had proportionately more exotic trees, by species and individuals, amongst their larger planted trees than older areas of housing. The majority of the species, and individuals, of the larger (≥10 cm DBH) trees planted in gardens still tend to be exotic species. In newer suburbs, gardens in wealthy areas had more native trees than gardens from poorer areas, while in older suburbs, poorer areas had more native big trees than wealthy areas. In combination, these describe, in detail unparalleled for at least in New Zealand, how the tree infrastructure of the city varies in space and time. This lays the groundwork for better understanding of how wildlife distribution and abundance, wild plant regeneration, and ecosystem services, are affected by the city’s trees.
A video made by Julian Vares about FESTA - the Festival of Transitional Architecture. The video includes explanations from FESTA director Jessica Halliday and key collaborators about what FESTA is about, and the important role it plays in the rebuild and recovery of Christchurch. It also includes a compilation of footage from the first three FESTA events of 2012, 2013 and 2014. This footage was shot by Rick Harvie (Belmont Productions), Peter Young (Fisheye Films), Ed Lust and John Chrisstoffels.
Photograph captioned by BeckerFraserPhotos, "Aerial view of the centre of the city, with the cathedral in the centre, and the art gallery in the foreground".
A sign for a community briefing to be held at Oxford Street grass area at Lyttelton Main School on Sunday 17 April 2.30pm. These signs were put up in all locations in Christchurch for each community briefing. The first series (6 March to 12 March) were held in 12 locations, second series (21 March to 26 March) in 10 locations and the third series (16 April to 18 April) in 8 locations.
A photograph of the earthquake-damaged to a house in Christchurch. The far wall has collapsed and many of the concrete blocks have spilled into the garden in front. Emergency tape has been draped in front of the wall as a cordon. A red sticker has also been stuck on the furthest window, indicating that the house is unsafe to enter.
A photograph of a portaloo outside a residential property in Christchurch. After the 22 February 2011 earthquake, many houses had no running water and were forced to use chemical toilets or portaloos placed along the street. There is flooding and liquefaction on the street in the foreground. Liquefaction silt has been piled on the side of the road and a road cone placed in front.
Photograph captioned by BeckerFraserPhotos, "The intersection of Colombo and Gloucester Streets, looking south down Colombo Street towards Cathedral Square. The soldiers are staffing the cordon as this is the main way through from one half of the central city red zone to the other half, which is now bisected by Gloucester Street".
An aerial photograph of Cathedral Square. Captions added by BeckerFraserPhotos identify the demolition sites of key buildings.
An aerial photograph of the Christchurch central city. The photograph has been captioned by BeckerFraserPhotos, "The central city, with the Majestic Theatre in the centre of the photograph. Lichfield Street runs from bottom left diagonally up the photograph to the top right. The City Council building is prominent in the bottom left corner and Latimer Square in the top left corner".
An aerial photograph of the Christchurch CBD. The photograph has been captioned by BeckerFraserPhotos, "This photograph shows the many tall CBD buildings, with the Hotel Grand Chancellor under demolition in the centre of the photograph. The street in the foreground running up the photograph from left to right is Lichfield Street with the old Bus Exchange clearly visible".
Well-validated liquefaction constitutive models are increasingly important as non-linear time history analyses become relatively more common in industry for key projects. Previous validation efforts of PM4Sand, a plasticity model specifically for liquefaction, have generally focused on centrifuge tests; however, pore pressure transducers installed at several free-field sites during the Canterbury Earthquake Sequence (CES) in Christchurch, New Zealand provide a relatively unique dataset to validate against. This study presents effective stress site response analyses performed in the finite difference software FLAC to examine the capability of PM4Sand to capture the generation of excess pore pressures during earthquakes. The characterization of the subsurface is primarily based on extensive cone penetration tests (CPT) carried out in Christchurch. Correlations based on penetration resistances are used to estimate soil parameters, such as relative density and shear wave velocity, which affect liquefaction behaviour. The resulting free-field FLAC model is used to estimate time histories of excess pore pressure, which are compared with records during several earthquakes in the CES to assess the suitability of PM4Sand.
Eccentrically Braced Frames (EBFs) are a widely used seismic resisting structural steel system. Since their inception in the late 1970s, they have been a viable option with an available stiffness that is between simple braced systems and moment resisting systems. A similar concept, the linked column frame (LCF), uses shear links between two closely spaced columns. In both cases, the key component is the active link or the shear link, and this component is the objective of this study. The performance of high rise EBF buildings in the 2010 and 2011 Christchurch earthquakes was beyond that which was expected, especially considering the very high accelerations recorded. As the concrete high-rises were torn down, two EBF buildings remained standing and only required some structural repair. These events prompted a renewed interest in bolted shear links, as well as their performance. While some research into replaceable shear links had already been done (Mansour, 2011), the objectives of this study were to improve on the shear link itself, with the consideration that links built in the future are likely to be bolted. The main components of this study were to: 1. Reduce or eliminate the requirements for intermediate web stiffeners, as they were suspected of being detrimental to performance. Furthermore, any reduction in stiffening requirements is a direct fabrication cost saving. Links with low web aspect ratios were found to achieve exceptional ductilities when no stiffeners were included, prompting new design equations. 2. Ensure that the stresses in the ends of links are adequately transferred into the endplates without causing fractures. Although most of the experimental links had web doubler plates included, four had varied lengths of such doubler plates from 0.0 in. to 8.0 in. The link without any doubler plates performed to a similar level to its peers, and thus it is likely that links with quality end details may not need web doubler plates at all. 3. Evaluate the performance of a link with double sided stiffeners without the use of web welds, as opposed to conventional single sided, welded stiffeners. This link performed well, and web-weld-less double sided stiffeners may be an economical alternative to conventional stiffeners for deeper sections of links. 4. Evaluate the performance of a link with thin endplates that are made efficient with the use of gusset plates. This link performed to an acceptable level and provides evidence for a cost effective alternative to thick endplates, especially considering the high overstrength end moments in links, typically requiring 16-bolt connections. 5. Examine the potential use of an alternative EBF arrangement where the collector beam is over sized, and the link section is formed by cutting out parts of the beam's web. After running a series of finite element models each with a unique variation, a number of approximate design rules were derived such that future research could develop this idea further experimentally. 6. Ensure that during testing, the secondary elements (members that are not the shear link), do not yield and are not close to yielding. None of the instrumented elements experienced any unexpected yielding, however the concerns for high stresses in the collector beam panel zone during design were warranted. The use of an existing New Zealand design equation is recommended as an extra check for design codes worldwide. The above objectives were mainly conducted experimentally, except: the data set for item 1 was greatly expanded through the use of a calibrated numerical model which was then used in an extensive parametric study; item 5 was purely finite element based; and, a small parametric study was included for item 3 in an attempt to expand on the trends found there.
A photograph of the earthquake damage to the Cycle Trading store on Manchester Street. The gable of the store has collapsed, and bricks and other rubble have fallen onto the footpath in front. A car parked on the street has been crushed by the fallen rubble. The word "Clear" has been spray-painted on the front of the car. Wire fencing has been placed around the building as a cordon.
Successful urban regeneration projects generate benefits that are realised over a much longer timeframe than normal market developments and benefits well beyond those that can be uplifted by a market developer. Consequently there is substantial evidence in the literature that successful place-making and urban regeneration projects are usually public-private partnerships and involve a funder, usually local or central government, willing to contribute ‘patient’ capital. Following the 2010 and 2011 earthquakes that devastated the centre of Christchurch, there was an urgent need to rebuild and revitalise the heart of the city, and increasing the number of people living in or near the city centre was seen as a key ingredient of that. In October 2010, an international competition was launched to design and build an Urban Village, a project intended to stimulate renewed residential development in the city. The competition attracted 58 entrants from around world, and in October 2013 the winning team was chosen from four finalists. However the team failed to secure sufficient finance, and in November 2015 the Government announced that the development would not proceed. The Government was unwilling or unable to recognise that an insistence on a pure market approach would not deliver the innovative sustainable village asked for in the competition brief, and failed to factor in the opportunity cost to government, local government, local businesses and the wider Christchurch community of delaying by many years the residential development of the eastern side of the city. As a result, the early vision of the vitality that a thriving residential neighbourhood would bring to the city has not yet been realised.
A photograph of Celia Wade-Brown, Mayor of Wellington, speaking at a graduation ceremony for more than 40 new civil defence volunteers in the Wellington Town Hall. Members of the Wellington Emergency Management Office team were presented certificates of appreciation during this event. The certificates were presented to the members to honour their involvement in the emergency response to the 22 February 2011 earthquakes in Christchurch.
A photograph of street art on the wall of a building on Colombo Street. The artwork is by Otis Frizzell and depicts police officer Constable Nao Yoshimizu comforting the grieving relative of an earthquake victim. Constable Yoshimizu acted as liaison officer for the families of Japanese victims of the earthquake. The mural was commissioned by the New Zealand Police as a recruitment advertisement.
The "Tree of Hope" at the River of Flowers event held in Riccarton Bush, commemorating the second anniversary of the 22 February earthquake. The photographer comments, "Luggage labels and pens were supplied, and people were encouraged to write a message of hope for Christchurch and tie it to the tree. Although the turn-out this year was just as big as last year's, there were not as many messages tied to the tree - perhaps we're all feeling less hopeful this year".
A photograph of the earthquake damage to the Cathedral of the Blessed Sacrament on Barbadoes Street. The tower on the right has crumbled and the masonry has fallen to the pavement below. A car has been crushed by the fallen rubble. The dome of the left tower has collapsed and the cross at the top of the building is on a lean.
A photograph of the earthquake-damaged buildings and rubble on Colombo Street near the intersection of St Asaph Street. The walls of the top storey of the buildings to the left have crumbled, and bricks and other rubble have fallen onto the footpath and road below. Wire fencing and police tape have been placed across the street as a cordon.
People write messages for the "Tree of Hope" at the River of Flowers event held in Riccarton Bush, commemorating the second anniversary of the 22 February earthquake. The photographer comments, "Luggage labels and pens were supplied, and people were encouraged to write a message of hope for Christchurch and tie it to the tree. Although the turn-out this year was just as big as last year's, there were not as many messages tied to the tree - perhaps we're all feeling less hopeful this year".
A photograph of a map used by emergency management personnel to inspect buildings after the 22 February 2011 earthquake. The map is of central Christchurch. Almost all of the blocks outside four streets (Moorhouse Avenue, Oxford Terrace, Kilmore Street, and Barbadoes Street) have been highlighted in yellow. Latimer Square has also been highlighted. A message written at the top of the map reads, "Query pile checked by dogs".
An aerial photograph of Hereford Street and Cathedral Square. The photograph has been captioned by BeckerFraserPhotos, "Hereford Street running across the foreground of this photograph, with Cathedral Square above. The IBIS Hotel and the ANZ Bank are staying, while the BNZ is currently being soft-stripped. Christ Church Cathedral officially has a status of 'partial demolish'".
Knowing how to rapidly rebuild disaster-damaged infrastructure, while deciding appropriate recovery strategies and catering for future investment is a matter of core interest to government decision makers, utility providers, and business sectors. The purpose of this research is to explore the effects of decisions and outcomes for physical reconstruction on the overall recovery process of horizontal infrastructure in New Zealand using the Canterbury and Kaikoura earthquakes as cases. A mixed approach including a systematic review, questionnaire survey and semi-structured interviews is used to capture perspectives of those involved in reconstruction process and gain insights into the effect of critical elements on infrastructure downtime. Findings from this research will contribute towards advancements of a systems dynamics model considering critical decision-making variables across phases of the reconstruction process to assess how these variables affect the rebuild process and the corresponding downtime. This project will improve the ability to explore alternative resilience improvement pathways and test the efficacy of alternative means for facilitating a faster and better reconstruction process.
This research investigates the validation of simulated ground motions on complex structural systems. In this study, the seismic responses of two buildings are compared when they are subjected to as-recorded ground motions and simulated ones. The buildings have been designed based on New Zealand codes and physically constructed in Christchurch, New Zealand. The recorded ground motions are selected from 40 stations database of the historical 22 Feb. 2011 Christchurch earthquake. The Graves and Pitarka (2015) methodology is used to generate the simulated ground motions. The geometric mean of maximum inter-story drift and peak floor acceleration are selected as the main seismic responses. Also, the variation of these parameters due to record to record variability are investigated. Moreover, statistical hypothesis testing is used to investigate the similarity of results between observed and simulated ground motions. The results indicate a general agreement between the peak floor acceleration calculated by simulated and recorded ground motions for two buildings. While according to the hypothesis tests result, the difference in drift can be significant for the building with a shorter period. The results will help engineers and researchers to use or revise the procedure by using simulated ground motions for obtaining seismic responses.
A photograph of Fred Mecoy, the Wellington City Council's Emergency Preparedness Manager, speaking at a graduation ceremony for more than 40 new civil defence volunteers in the Wellington Town Hall. Members of the Wellington Emergency Management Office team were presented certificates of appreciation during this event. The certificates were presented to the members to honour their involvement in the emergency response to the 22 February 2011 earthquakes in Christchurch.
Background Liquefaction induced land damage has been identified in more than 13 notable New Zealand earthquakes within the past 150 years, as presented on the timeline below. Following the 2010-2011 Canterbury Earthquake Sequence (CES), the consequences of liquefaction were witnessed first-hand in the city of Christchurch and as a result the demand for understanding this phenomenon was heightened. Government, local councils, insurers and many other stakeholders are now looking to research and understand their exposure to this natural hazard.
A photograph of a Wellington Emergency Management Office Emergency Response Team member talking to a member of the Professional Building Services on Gloucester Street. In the background is the Press House building with many cracks in the façade. Bits of bricks and other debris are scattered across the footpath. Some of the windows above the facade have broken. USAR codes have been spray-painted on one of the bottom-storey windows.
A photograph of the earthquake damage to the Country Theme store on the corner of Manchester and St Asaph Streets. Sections of the second storey walls have crumbled, and the bricks have fallen onto the footpath below. Wire fences have been placed around the building as a cordon. Red stickers on the front door and the wire fence indicate that the building is not safe to enter.
A photograph of a make-shift toilet in the Christchurch Art Gallery. A sign behind it reads, "Portaloos Department. We know that 80,000 people need loos. We have 900-1800 available or coming, We don't need to be told people need loos. Thank you. We're number one with your number twos!". Signs below this read, "Toilet Occupied", "Toilet Vacant" and, "In Tray". The Art Gallery was used as the temporary headquarters for Civil Defence after the 22 February 2011 earthquake.
Yes, it was a joke. The tours, that is, not the yard filled with earthquake-caused sand volcanos. They were very real. You can see one covering the driveway in this photo. The signs read as follows. "Tours run 1/2 hourly. $5.25 admission. Eftpos unavailable." "If you think this is bad... you should see the back!"