Search

found 9155 results

Images for Earthquake Damage; more images...

Research papers, University of Canterbury Library

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.

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.

Images, UC QuakeStudies

A photograph looking west down Hereford Street from the intersection with Manchester Street. Wire fencing has been placed on both sides of the street to cordon off earthquake-damaged buildings. To the right, bricks have spilled across the road and footpath.

Images, UC QuakeStudies

A photograph of the earthquake damage to the Bob Brown's Hi-Fi Sounds building on the corner of Gloucester and Armagh Streets. Many of the windows have broken and wire fencing has been placed around the building as a cordon.

Images, UC QuakeStudies

A photograph of the earthquake damage to the Bob Brown's Hi-Fi Sounds building on the corner of Gloucester and Armagh Streets. Many of the windows have broken and wire fencing has been placed around the building as a cordon.

Images, UC QuakeStudies

St Elmo Courts, a NZHPT heritage building on the corner of Hereford and Montreal Streets. The building was severely damaged during the 4 September earthquake, with diagonal cracking between the windows. Scaffolding has been placed around the bottom of the building.

Images, UC QuakeStudies

A photograph of the earthquake damage the brick fence of a house in Christchurch. Bricks from the broken fence have been stacked on the footpath in front. Liquefaction has been piled on the footpath and road cones placed in front.

Images, UC QuakeStudies

A photograph of the earthquake damage the brick fence of a house in Christchurch. Bricks from the broken fence have been stacked on the footpath in front. Liquefaction has been piled on the footpath and road cones placed in front.

Articles, UC QuakeStudies

Posters which describe the earthquake damage, planned restoration methods and historic information about the Bridge of Remembrance and Memorial Arch. These posters were hung on the fencing around the Bridge and Arch to inform the public about the work taking place.

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.

Images, Alexander Turnbull Library

Photographs of central Christchurch after the 2010-2012 earthquakes taken 25 February 2012 by Sean McMahon. Locations are chiefly Manchester, Saint Asaph, Cashel, Columbo and Lichfield Streets, and the Bridge of Remembrance. Images show fencing around areas closed to the public, damaged and collapsed commercial buildings, cleared sites, re-opened Cashel Street area with shops and a cafe. Source of title - Title supplied by Library Quantity: 34 digital photograph(s).

Images, Alexander Turnbull Library

In the living room of a house half-ruined by the Christchurch earthquake a decrepit and useless-looking man in a grubby white singlet doses in his armchair with a glass of beer in his hand; his wife whispers to a friend 'Just between you and me, I'm hoping to have him red-stickered!' Context - The two Christchurch earthquakes of 4 September 2010 and 22 February 2011 and the technique of using different coloured stickers to designate the degree of damage to buildings - 'red' indicates that it needs to be demolished. Colour and black and white versions available Quantity: 2 digital cartoon(s).

Audio, Radio New Zealand

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.

Audio, Radio New Zealand

The state of emergency in Christchurch has just been extended until midday on Wednesday. In latest developments Canterbury Civil Defence is now warning people to prepare for potential flooding, only two days after the major earthquake that caused widespread damage to much of the region.

Audio, Radio New Zealand

The Christchurch earthquake last February forced many circus performers to flee the city in search of work. Their base - the Circo Arts school - was damaged in the quake and is likely to be demolished. But they're now slowly returning, as a new base for circus performers is established in the city.

Images, UC QuakeStudies

A photograph of the earthquake damage to a property in the Christchurch central city. Part of the roof of the property has collapsed, spilling material onto the balcony below. A sign in the foreground reads, "Wots your councillor doing for your water?".

Images, UC QuakeStudies

A photograph of the lens of the Townsend Telescope. The lens is the most crucial component of the telescope. Despite damage to the surrounding parts, the lens was unharmed during the 22 February 2011 earthquake. Because of this, the telescope can be restored.