BeckerFraserPhotos October 2011 photograph 612

Images, UC QuakeStudies

Photograph captioned by BeckerFraserPhotos, "CBD with Christ's College in the foreground, Canterbury Museum and the Arts Centre".

Koen Broekema's Photograph 012

Images, UC QuakeStudies

A crane and a digger demolish the Gallery Apartments building on Gloucester Street. A sign that reads, 'Road closed' has been placed in front of the security fencing.

BeckerFraserPhotos December 2011 photograph 0310

Images, UC QuakeStudies

An aerial photograph captioned by BeckerFraserPhotos, "Central city blocks bounded by Colombo Street, Hereford Street, Cashel Street, and High Street".

BeckerFraserPhotos December 2011 photograph 1961

Images, UC QuakeStudies

A photograph captioned by BeckerFraserPhotos, "The corner of Victoria Street and Kilmore Streets, overlooking the demolition site of the Copthorne Hotel on Durham Street".

BeckerFraserPhotos October 2011 photograph 614

Images, UC QuakeStudies

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".

BeckerFraserPhotos December 2011 photograph 0276

Images, UC QuakeStudies

An aerial photograph of the Christchurch City Council Civic Offices and surrounding buildings. The photograph has been captioned by BeckerFraserPhotos, "The River Avon runs through this photograph and marks the western edge of the red zone".

Monotonic and cyclic bond behaviour of deformed bars in reinforced concret…

Research papers, University of Canterbury Library

A major lesson from the 2011 Christchurch earthquake was the apparent lack of ductility of some lightly reinforced concrete (RC) wall structures. In particular, the structural behaviour of the critical wall in the Gallery Apartments building demonstrated that the inelastic deformation capacity of a structure, as well as potentially brittle failure of the reinforcement, is dependent on the level of bond deterioration between reinforcement and surrounding concrete that occurs under seismic loading. This paper presents the findings of an experimental study on bond behaviour between deformed reinforcing bars and the surrounding concrete. Bond strength and relative bond slip was evaluated using 75 pull-out tests under monotonic and cyclic loading. Variations of the experiments include the loading rate, loading history, concrete strength (25 to 70 MPa), concrete age, cover thickness, bar diameter (16 and 20 mm), embedded length, and the position of the embedded bond region within the specimen (deep within or close to free surface). Select test results are presented with inferred implications for RC structures.

Assessment of the minimum vertical reinforcement limits for RC walls

Research papers, The University of Auckland Library

During the 2010/2011 Canterbury earthquakes, several reinforced concrete (RC) walls in multi-storey buildings formed a single crack in the plastic hinge region as opposed to distributed cracking. In several cases the crack width that was required to accommodate the inelastic displacement of the building resulted in fracture of the vertical reinforcing steel. This type of failure is characteristic of RC members with low reinforcement contents, where the area of reinforcing steel is insufficient to develop the tension force required to form secondary cracks in the surrounding concrete. The minimum vertical reinforcement in RC walls was increased in NZS 3101:2006 with the equation for the minimum vertical reinforcement in beams also adopted for walls, despite differences in reinforcement arrangement and loading. A series of moment-curvature analyses were conducted for an example RC wall based on the Gallery Apartments building in Christchurch. The analysis results indicated that even when the NZS 3101:2006 minimum vertical reinforcement limit was satisfied for a known concrete strength, the wall was still susceptible to sudden failure unless a significant axial load was applied. Additionally, current equations for minimum reinforcement based on a sectional analysis approach do not adequately address the issues related to crack control and distribution of inelastic deformations in ductile walls.