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BeckerFraserPhotos May 2011 photograph 0393

Images, UC QuakeStudies

Damage to the backs of buildings in Cashel Mall. The upper storeys have partially collapsed, and large cracks run through the lower parts of the buildings.

Photograph by Paul Corliss 2164

Images, UC QuakeStudies

A photograph of a damaged house perched on the edge of the cliffs above Sumner. The photograph is captioned by Paul Corliss, "Redcliffs from Sumner Beach".

BeckerFraserPhotos February 2012 photograph 0103

Images, UC QuakeStudies

A photograph of a damaged house. The photograph is captioned by BeckerFraserPhotos, "This house is clearly unoccupied. 8 Jean Batten Place, Horseshoe Lake, Burwood".

BeckerFraserPhotos October 2010 photograph 042

Images, UC QuakeStudies

A photograph of road damage in Queensbury Street. The photographer says, "Many of the road disturbances are along the curb side requiring fill to level them".

Photograph by Paul Corliss 3332

Images, UC QuakeStudies

A photograph of a fire-damaged building in High Street. The photograph is captioned by Paul Corliss, "Tuam Street and High Street shops, CBD. By Alice's".

BeckerFraserPhotos March 2013 photograph 087

Images, UC QuakeStudies

An aerial photograph looking north-west over High Street with the damaged McKenzie & Willis store in the centre, and Alice in Videoland to the left.

BeckerFraserPhotos March 2012 photograph 007

Images, UC QuakeStudies

Photograph captioned by BeckerFraserPhotos, "The buildings of the former Wards Brewery, also known as Crichton Cobbers, further damaged in the 23 December 2011 earthquake".

BeckerFraserPhotos April 2011 photograph 057

Images, UC QuakeStudies

A view over cordon fencing towards the damaged Ground Culinary Centre and cafe. Bricks have crumbled from the walls and remain piled up on the footpath.

Post-Earthquake Residual Capacity of Reinforced Concrete Plastic Hinges

Research papers, The University of Auckland Library

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.

BeckerFraserPhotos February 2013 photograph 072

Images, UC QuakeStudies

Weeds are growing through cracks in the pavement outside abandoned properties on Seabreeze Close, Bexley.

BeckerFraserPhotos October 2011 photograph 245

Images, UC QuakeStudies

Photograph captioned by BeckerFraserPhotos, "Orari Street, Bexley. Changes to the water level have taken place in this property".

BeckerFraserPhotos September 2011 photograph 417

Images, UC QuakeStudies

Photograph captioned by BeckerFraserPhotos, "Broken pavement at the entrance to Avon Rowing Club, at Kerrs Reach".

BeckerFraserPhotos February 2011 photograph 086

Images, UC QuakeStudies

Damage to the A and T Burt building on Ferry Road in Woolston. Masonry has collapsed from the top section of the building's front wall, exposing its ceiling.

BeckerFraserPhotos February 2011 photograph 098

Images, UC QuakeStudies

Damage to the Music Centre of Christchurch building on Barbadoes Street. Tarpaulins have been used to weather proof gaps in the building's gables from where masonry has fallen.

BeckerFraserPhotos February 2011 photograph 099

Images, UC QuakeStudies

Damage to the Music Centre of Christchurch building on Barbadoes Street. Tarpaulins have been used to weather proof gaps in the building's gables from where masonry has fallen.