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Research papers, The University of Auckland Library

A review of the literature showed the lack of a truly effective damage avoidance solution for timber or hybrid timber moment resisting frames (MRFs). Full system damage avoidance selfcentring behaviour is difficult to achieve with existing systems due to damage to the floor slab caused by beam-elongation. A novel gravity rocking, self-centring beam-column joint with inherent and supplemental friction energy dissipation is proposed for low-medium rise buildings in all seismic zones where earthquake actions are greater than wind. Steel columns and timber beams are used in the hybrid MRF such that both the beam and column are continuous thus avoiding beam-elongation altogether. Corbels on the columns support the beams and generate resistance and self-centring through rocking under the influence of gravity. Supplemental friction sliders at the top of the beams resist sliding of the floor whilst dissipating energy as the floor lifts on the corbels and returns. 1:20 scale tests of 3-storey one-by-two bay building based on an earlier iteration of the proposed concept served as proof-of-concept and highlighted areas for improvement. A 1:5 scale 3-storey one-by-one bay building was subsequently designed. Sub-assembly tests of the beam-top asymmetric friction sliders demonstrated repeatable hysteresis. Quasi-static tests of the full building demonstrated a ‘flat bottomed’ flag-shaped hysteresis. Shake table tests to a suite of seven earthquakes scaled for Wellington with site soil type D to the serviceability limit state (SLS), ultimate limit state (ULS) and maximum credible event (MCE) intensity corresponding to an average return period of 25, 500 and 2500 years respectively were conducted. Additional earthquake records from the 22 February 2011 Christchurch earthquakes we included. A peak drift of 0.6%, 2.5% and 3.8% was reached for the worst SLS, ULS and MCE earthquake respectively whereas a peak drift of 4.5% was reached for the worst Christchurch record for tests in the plane of the MRF. Bi-directional tests were also conducted with the building oriented at 45 degrees on the shake table and the excitation factored by 1.41 to maintain the component in the direction of the MRF. Shear walls with friction slider hold-downs which reached similar drifts to the MRF were provided in the orthogonal direction. Similar peak drifts were reached by the MRF in the bi-directional tests, when the excitation was amplified as intended. The building self-centred with a maximum residual drift of 0.06% in the dynamic tests and demonstrated no significant damage. The member actions were magnified by up to 100% due to impact upon return of the floor after uplift when the peak drift reached 4.5%. Nonetheless, all of the members and connections remained essentially linearelastic. The shake table was able to produce a limited peak velocity of 0.275 m/s and this limited the severity of several of the ULS, MCE and Christchurch earthquakes, especially the near-field records with a large velocity pulse. The full earthquakes with uncapped velocity were simulated in a numerical model developed in SAP2000. The corbel supports were modelled with the friction isolator link element and the top sliders were modelled with a multi-linear plastic link element in parallel with a friction spring damper. The friction spring damper simulated the increase in resistance with increasing joint rotation and a near zero return stiffness, as exhibited by the 1:5 scale test building. A good match was achieved between the test quasi-static global force-displacement response and the numerical model, except a less flat unloading curve in the numerical model. The peak drift from the shake table tests also matched well. Simulations were also run for the full velocity earthquakes, including vertical ground acceleration and different floor imposed load scenarios. Excessive drift was predicted by the numerical model for the full velocity near-field earthquakes at the MCE intensity and a rubber stiffener for increasing the post joint-opening stiffness was found to limit the drift to 4.8%. Vertical ground acceleration had little effect on the global response. The system generates most of its lateral resistance from the floor weight, therefore increasing the floor imposed load increased the peak drift, but less than it would if the resistance of the system did not increase due to the additional floor load. A seismic design procedure was discussed under the framework of the existing direct displacement-based design method. An expression for calculating the area-based equivalent viscous damping (EVD) was derived and a conservative correction factor of 0.8 was suggested. A high EVD of up to about 15% can be achieved with the proposed system at high displacement ductility levels if the resistance of the top friction sliders is maximised without compromising reliable return of the floor after uplift. Uniform strength joints with an equal corbel length up the height of the building and similar inter-storey drifts result in minimal relative inter-floor uplift, except between the first floor and ground. Guidelines for detailing the joint for damage avoidance including bi-directional movement were also developed.

Research papers, The University of Auckland Library

This paper analyses the city of Christchurch, New Zealand, which has been through dramatic changes since it was struck by a series of earthquakes of different intensities between 2010 and 2011. The objective is to develop a deeper understanding of resilience by looking at changes in green and grey infrastructures. The study can be helpful to reveal a way of doing comparative analysis using resilience as a theoretical framework. In this way, it might be possible to assess the blueprint of future master plans by considering how important the interplay between green and grey infrastructure is for the resilience capacity of cities.

Images, eqnz.chch.2010

The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. The New Zealand Army, along with Police, were minding the cordons. Note: these photos were taken on a cellphone; mind the quality.

Images, eqnz.chch.2010

The September Canterbury earthquake. These pictures were taken of The New Zealand Army, along with Police, minding the cordons. This was beside The Press building, and behind the Christchurch Cathedral. Note: these photos were taken on a cellphone; mind the quality.

Images, eqnz.chch.2010

The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. A second hand dealer store. This is next to Penny Lane which had to relocate down the street. Note: these photos were taken on a cellphone; mind the quality.

Images, eqnz.chch.2010

The now vacated Christchurch City Council building suffered some damage in the magnitude 7.1 earthquake that struck Christchurch on Saturday 4 September 2010.

Images, eqnz.chch.2010

The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. The New Zealand Army, along with Police, were minding the cordons. Note: these photos were taken on a cellphone; mind the quality.

Images, eqnz.chch.2010

Victoria Apartments demolition is under way on a walk around the city to find out what is happening in the city. Feb 17, 2014 Christchurch New Zealand. "soft-stripped", which means that any remaining belongings will be removed, as well as furnishings and internal walls.

Images, eqnz.chch.2010

Working at getting things out of the Victoria Square before it is demolished. www.stuff.co.nz/the-press/news/christchurch-earthquake-20... What I found on my walk around the city January 15, 2014 Ch...

Images, eqnz.chch.2010

The centennial pool demolition is under way. On a walk around the city to catch up on events happening June 18, 2014 Christchurch New Zealand. Swimsuits have been hung on the fence around the Centennial Pool by campaigners against the complex's demolition. The Armagh St facility is being pulled down to make way for the new Margaret Mahy Fami...

Images, eqnz.chch.2010

On a walk around the neighbourhood, December 3, 2013, Christchurch New Zealand. www.stuff.co.nz/the-press/christchurch-life/avenues/featu...

Images, eqnz.chch.2010

On a walk around the city to find out of the Demolition work on the Victoria Sq Apartments. Taking up a digger it took some times to manmover it up there! Feb 17, 2014 Christchurch New Zealand. www.stuff.co.nz/the-press/ne...

Images, eqnz.chch.2010

After my visit at the hospital for physiotherapy on my hand I took a walk around the city on my way home. Demolition of the Victoria Square apartments February 12, 2014 Christchurch New Zealand. www.s...

Images, eqnz.chch.2010

On a walk around the city to catch up on what is happening May 29, 2014 Christchurch New Zealand. Demolition work on Christchurch's "distinctive" former civic building is under way. The category-2 heritage building was designed by G A J Hart and opened in 1939 as the Miller's department store. It featured the South Island's first escalator, w...

Images, eqnz.chch.2010

The earthquake re-pair work has started on the Knox Church on Bealey Avenue, August 14, 2013 Christchurch New Zealand. While building after building is torn down in Christchurch, plans are in place to ensure as much of a 131-year-old church is retained as possible. Knox Church on Bealey Avenue suffered major damage in the February 22 earthquak...

Images, eqnz.chch.2010

What I found on a walk around the city Christchurch November 20, 2013 New Zealand. www.isaactheatreroyal.co.nz/ en.wikipedia.org/wiki/2011_Christchurch_earthquake

Images, eqnz.chch.2010

Demolition of the old Millers building is just about complemented. On my walk around the city in the rain.. thought it may have stopped.. but didn't so I just kept walking! June 12, 2014 Christchurch New Zealand.

Images, eqnz.chch.2010

Knox Church earthquake repair/rebuild on a walk around Christchurch December 11, 2013 New Zealand. www.stuff.co.nz/the-press/news/christchurch-earthquake-20... All about our ear...

Images, eqnz.chch.2010

Earthquake damaged building on a Walk around the city, May 1, 2014 Christchurch New Zealand. Demolition work on Christchurch's "distinctive" former civic building is under way. The category-2 heritage building was designed by G A J Hart and opened in 1939 as the Miller's department store. It featured the South Island's first escalator, which...

Images, eqnz.chch.2010

The former Government Life building in Christchurch's Cathedral Square will be demolished. On my walk around the city May 21, 2014 Christchurch New Zealand. www.stuff.co.nz/the-press/news/christch...

Images, eqnz.chch.2010

Christchurch "New Zealand" architecture building "Demolition of old Millers building" demolition detail rubbleDemolition started on the old Millers building on a walk around Christchurch May 6, 2013 New Zealand. The building was originally designed in 1935 by G. A. Hart for the retail store, factory and warehouse Millers and was completed in 19...

Images, eqnz.chch.2010

Demolition work on Christchurch's "distinctive" former civic building and the Front Runner store. On a walk around Christchurch May 9, 2013 New Zealand. Demolition work on Christchurch's "distinctive" former civic building is under way. The category-2 heritage building was designed by G A J Hart and opened in 1939 as the Miller's department s...

Images, eqnz.chch.2010

The centennial pool demolition is under way. On a walk around the city to catch up on events happening June 18, 2014 Christchurch New Zealand. Swimsuits have been hung on the fence around the Centennial Pool by campaigners against the complex's demolition. The Armagh St facility is being pulled down to make way for the new Margaret Mahy Fami...

Images, eqnz.chch.2010

I am going away for a short time for a holiday and well get back to you all when I get home. Demotion of the Victoria Sq apartments on a walk around the city Feb 26, 2014 Christchurch New Zealand. www...

Images, eqnz.chch.2010

The centennial pool demolition is under way. On a walk around the city to catch up on events happening June 18, 2014 Christchurch New Zealand. Swimsuits have been hung on the fence around the Centennial Pool by campaigners against the complex's demolition. The Armagh St facility is being pulled down to make way for the new Margaret Mahy Fami...

Images, eqnz.chch.2010

Earthquake damaged building on a Walk around the city, May 1, 2014 Christchurch New Zealand. Demolition work on Christchurch's "distinctive" former civic building is under way. The category-2 heritage building was designed by G A J Hart and opened in 1939 as the Miller's department store. It featured the South Island's first escalator, which...