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Images, eqnz.chch.2010

20160703_144759_GT-S7275T-04 New sea wall at Redcliffs (185/366) I went for a drive in my second car mainly to charge the battery up and forgot to take my camera gear so only had my phone. This is the new rock wall to replace the severely damaged previous one (in the February 2011 earthquake). Work is still underway on the car parking and p...

Research papers, University of Canterbury Library

Bulk rock strength is greatly dependent on fracture density, so that reductions in rock strength associated with faulting and fracturing should be reflected by reduced shear coupling and hence S-wave velocity. This study is carried out along the Canterbury rangefront and in Otago. Both lie within the broader plate boundary deformation zone in the South Island of New Zealand. Therefore built structures are often, , located in areas where there are undetected or poorly defined faults with associated rock strength reduction. Where structures are sited near to, or across, such faults or fault-zones, they may sustain both shaking and ground deformation damage during an earthquake. Within this zone, management of seismic hazards needs to be based on accurate identification of the potential fault damage zone including the likely width of off-plane deformation. Lateral S-wave velocity variability provides one method of imaging and locating damage zones and off-plane deformation. This research demonstrates the utility of Multi-Channel Analysis of Surface Waves (MASW) to aid land-use planning in such fault-prone settings. Fundamentally, MASW uses surface wave dispersive characteristics to model a near surface profile of S-wave velocity variability as a proxy for bulk rock strength. The technique can aid fault-zone planning not only by locating and defining the extent of fault-zones, but also by defining within-zone variability that is readily correlated with measurable rock properties applicable to both foundation design and the distribution of surface deformation. The calibration sites presented here have well defined field relationships and known fault-zone exposure close to potential MASW survey sites. They were selected to represent a range of progressively softer lithologies from intact and fractured Torlesse Group basement hard rock (Dalethorpe) through softer Tertiary cover sediments (Boby’s Creek) and Quaternary gravels. This facilitated initial calibration of fracture intensity at a high-velocity-contrast site followed by exploration of the limits of shear zone resolution at lower velocity contrasts. Site models were constructed in AutoCAD in order to demonstrate spatial correlations between S-wave velocity and fault zone features. Site geology was incorporated in the models, along with geomorphology, river profiles, scanline locations and crosshole velocity measurement locations. Spatial data were recorded using a total-station survey. The interpreted MASW survey results are presented as two dimensional snapshot cross-sections of the three dimensional calibration-site models. These show strong correlations between MASW survey velocities and site geology, geomorphology, fluvial profiles and geotechnical parameters and observations. Correlations are particularly pronounced where high velocity contrasts exist, whilst weaker correlations are demonstrated in softer lithologies. Geomorphic correlations suggest that off-plane deformation can be imaged and interpreted in the presence of suitable topographic survey data. A promising new approach to in situ and laboratory soft-rock material and mass characterisation is also presented using a Ramset nail gun. Geotechnical investigations typically involve outcrop and laboratory scale determination of rock mass and material properties such as fracture density and unconfined compressive strength (UCS). This multi-scale approach is espoused by this study, with geotechnical and S-wave velocity data presented at multiple scales, from survey scale sonic velocity measurements, through outcrop scale scanline and crosshole sonic velocity measurements to laboratory scale property determination and sonic velocity measurements. S-wave velocities invariably increased with decreasing scale. These scaling relationships and strategies for dealing with them are investigated and presented. Finally, the MASW technique is applied to a concealed fault on the Taieri Ridge in Macraes Flat, Central Otago. Here, high velocity Otago Schist is faulted against low velocity sheared Tertiary and Quaternary sediments. This site highlights the structural sensitivity of the technique by apparently constraining the location of the principal fault, which had been ambiguous after standard processing of the seismic reflection data. Processing of the Taieri Ridge dataset has further led to the proposal of a novel surface wave imaging technique termed Swept Frequency Imaging (SFI). This inchoate technique apparently images the detailed structure of the fault-zone, and is in agreement with the conventionally-determined fault location and an existing partial trench. Overall, the results are promising and are expected to be supported by further trenching in the near future.

Videos, UC QuakeStudies

A video of an interview with Terry Huggins about a boulder crashing into the side of his neighbour's house in Sumner. The boulder came lose from the cliffs above and smashed through the deck of the house into one of the supporting poles. It is the third large boulder to hit the house, with one also lodged in a bedroom.

Images, UC QuakeStudies

A damaged house teetering on the edge of the cliff in Sumner. Below, shipping containers along the edge of Peacock's Gallop protect the road from further rockfall. The photographer comments, "About four meters of the rock face collapsed on June 13 undermining several houses along the cliff top".

Images, UC QuakeStudies

A digital copy of a painting by Hamish Allan. The painting is titled, 'Garden City III, Tunnel control' and was painted in 2013. The original painting is acrylic on linen and measures 400 by 400mm.

Videos, UC QuakeStudies

A video of an interview with Mark Forster, Operations Manager of the Christchurch Gondola, about the revamp of the gondola. The attraction has been closed since 22 February 2011 while the café and restaurant is being renovated and the rock fall from the hill above mitigated.

Research papers, University of Canterbury Library

Slender precast concrete wall panels are currently in vogue for the construction of tall single storey warehouse type buildings. Often their height to thickness ratio exceed the present New Zealand design code (NZS 3101) limitations of 30:1. Their real performance under earthquake attack is unknown. Therefore, this study seeks to assess the dynamic performance of slender precast concrete wall panels with different base connection details. Three base connections (two fixed base and one rocking) from two wall specimens with height to thickness ratios of 60:1 were tested under dynamic loading. The two fixed based walls had longitudinal steel volumes of 1.27% to 0.54% and were tested on the University of Canterbury shaking table to investigate their proneness to out-of-plane buckling. Based on an EUler-type theoretical formula derived as part of the study, an explanation is made as to why walls with high in-plane capacity are more prone to buckling. The theory was validated against the present and past experimental evidence. The rocking base connection designed and built in accordance with a damage avoidance philosophy was tested on the shaking table in a similar fashion to the fixed base specimens. Results show that in contrast with their fixed base counterparts, rocking walls can indeed fulfil a damage-free design objective while also remaining stable under strong earthquake ground shaking.

Audio, Radio New Zealand

It's seven years today since Christchurch was rocked by the magnitude 6.3 earthquake. It killed 185 people, injured thousands more and led to whole suburbs and most of the central city being demolished. Seven years on, the rebuild is still underway and some residents are still struggling to get the repairs they want.

Images, UC QuakeStudies

Two workers inspect fuses placed in an embankment during reinforcement work. The photographer comments, "This is the reinforcing of an embankment in the port of Lyttelton, which partly collapsed in the Christchurch earthquakes. They are using the same equipment as used for blowing up rock faces to mend them".

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.

Videos, UC QuakeStudies

A video of an interview with Robin Judkins, Canterbury personality and Coast to Coast founder, about his experiences during the 22 February 2011 earthquake, and the changes to Christchurch. This video is part of The Press's 'Christchurch, one year after February 22, 2011' series.

Images, UC QuakeStudies

A painting wrapped around the side of one of the shipping containers in Sumner. Shipping containers have been placed along Main Road to protect people from rock fall. The artwork is part of the ContainerArt project which aims to turn the fixture of shipping containers in the Sumner community into a positive by turning them into works of art.

Audio, Radio New Zealand

Tomorrow will mark four years since a huge 7.8 magnitude earthquake rocked North Canterbury. As well as severely damaging homes and roads, it left some hill country farms in the area with up to 40 percent of their land unusable. Four years on, sheep and beef farmers are finding new ways to work. Rural reporter, Maja Burry and cameraman Nate McKinnon have the story.

Images, UC QuakeStudies

Photograph captioned by Fairfax, "Christchurch Earthquake. Christchurch was rocked by a large aftershock shortly after 8am this morning. Linemen cutting power to a damaged line outside an old historic building on the corner of Montreal Street and Moorhouse Avenue which will have work done to it to try and save as much as they can".

Images, UC QuakeStudies

Photograph captioned by Fairfax, "Christchurch was rocked by a large aftershock shortly after 8am this morning. Social Development Minister Paula Bennett has donated money to the thousand of students who have filled the suburbs lending a hand to residents to clean up their properties. Bennett gets a lift with volunteer Bernie Shaperio in his Jeep".

Images, UC QuakeStudies

Photograph captioned by Fairfax, "Christchurch Earthquake. Christchurch was rocked by a large aftershock shortly before 8am this morning. Linemen cutting power to a damaged line outside an old historic building on the corner of Montreal Street and Moorhouse Avenue which will have work done to it to try and save as much as they can".

Images, UC QuakeStudies

Photograph captioned by Fairfax, "Christchurch Earthquake. Christchurch was rocked by a large aftershock shortly after 8am this morning. Linemen cutting power to a damaged line outside an old historic building on the corner of Montreal Street and Moorhouse Avenue which will have work done to it to try and save as much as they can".

Images, UC QuakeStudies

Photograph captioned by Fairfax, "Christchurch Earthquake. Christchurch was rocked by a large aftershock shortly after 8am this morning. Linemen cutting power to a damaged line outside an old historic building on the corner of Montreal Street and Moorhouse Avenue which will have work done to it to try and save as much as they can".

Images, UC QuakeStudies

A photograph of an All Right? advertisement in a newspaper. The advertisement depicts an 'All Rightie' listening to music and dancing, and reads, "Classical? Jazz? Punk rock? Everyone needs to let their hair down now and then." All Right? posted the photograph on their Facebook page on 13 September 2013 at 4:10pm.