Shake Table Testing of a Near Full Scale Three-storey Friction Based Low D…

Research papers, University of Canterbury Library

Recent severe earthquakes, such as the 2010-2011 Christchurch earthquake series, have put emphasis on building resilience all over the world. To achieve such resilience, procedures for low damage seismic design have been developed to satisfy both life safety requirements and the need to minimize undesirable economic effects of required building repair or structural member replacement following a major earthquake. Seismic resisting systems following this concept are expected to withstand severe earthquakes without requiring major post-earthquake repairs, using isolating mechanisms or sacrificial systems that either do not need repair or are readily repairable or replaceable. These include the sliding hinge joint with asymmetric friction connections (SHJAFCs) in beam-to-column connections of the moment resisting steel frames (MRSFs) and symmetric friction connections (SFCs) in braces of the braced frames. A 9 m tall, configurable three-storey steel framed composite floor building incorporating frictionbased connections is to be tested using two linked bi-directional shake tables at the International joint research Laboratory of Earthquake Engineering (ILEE) facilities, Shanghai, China. The structural systems are configurable, allowing different moment and braced frame structural systems tested in two horizontal directions. The structure is designed and detailed to undergo, at worst, minor damage under a planned series of severe earthquakes.

Shaking table testing of a three-storey steel frame building incorporating…

Research papers, University of Canterbury Library

Recent severe earthquakes, such as Christchurch earthquake series, worldwide have put emphasis on building resilience. In resilient systems, not only life is protected, but also undesirable economic effects of building repair or replacement are minimized following a severe earthquake. Friction connections are one way of providing structure resilience. These include the sliding hinge joint with asymmetric friction connections (SHJAFCs) in beam-to-column connections of the moment resisting steel frames (MRSFs), and the symmetric friction connections (SFCs) in braces of the braced frames. Experimental and numerical studies on components have been conducted internationally. However, actual building performance depends on the many interactions, occurring within a whole building system, which may be difficult to determine accurately by numerical modelling or testing of structural components alone. Dynamic inelastic testing of a full-scale multi-storey composite floor building with full range of non-structural elements (NSEs) has not yet been performed, so it is unclear if surprises are likely to occur in such a system. A 9 m tall three-storey configurable steel framed composite floor building incorporating friction-based connections is to be tested using two linked bi-directional shake tables at the International joint research Laboratory of Earthquake Engineering (ILEE) facilities, Shanghai, China. Beams and columns are designed to remain elastic during an earthquake event, with all non-linear behaviour occurring through stable sliding frictional behaviour, dissipating energy by SHJAFCs used in MRFs and SFCs in braced frames, with and without Belleville springs. Structural systems are configurable, allowing different moment and braced frame structural systems to be tested in two horizontal directions. In some cases, these systems interact with rocking frame or rocking column system in orthogonal directions subjected to unidirectional and bidirectional horizontal shaking. The structure is designed and detailed to undergo, at worst, minor damage under series of severe earthquakes. NSEs applied include precast-concrete panels, glass curtain walling, internal partitions, suspended ceilings, fire sprinkler piping as well as some other common contents. Some of the key design considerations are presented and discussed herein

Lack of engineering assessments investigated

Audio, Radio New Zealand

A lack of building inspections and the engineers to carry them out has come under further scrutiny at the Royal Commission of inquiry into the Canterbury earthquakes.

Engineering profession is in crisis - engineer

Audio, Radio New Zealand

A structural engineer has told the Canterbury Earthquakes Royal Commission that illegal building techniques are being used in the Christchurch rebuild because the engineering profession is in crisis.

Assessing collapse capacity and risk in subsequent ground motions using SH…

Research papers, University of Canterbury Library

Predicting building collapse due to seismic motion is critical in design and more so after a major event. Damaged structures can appear sound, but collapse under following major events. There can thus be significant risk in decision making after a major seismic event concerning the safe occupation of a building or surrounding areas, versus the unknown impact of unknown major aftershocks. Model-based pushover analyses are effective if the structural properties are well understood, which is not valid post-event when this risk information is most useful. This research combines Hysteresis Loop Analysis (HLA) structural health monitoring (SHM) and Incremental Dynamic Analysis (IDA) methods to determine collapse capacity and probability of collapse for a specific structure, at any time, a range of earthquake excitations to ensure robustness. The nonlinear dynamic analysis method presented enables constant updating of building performance predictions using post-event SHM results. The resulting combined methods provide near real-time updating of collapse fragility curves as events progress, quantifying the change of collapse probability or seismic induced losses for decision-making - a novel, higher resolution risk analysis than previously available. The methods are not computationally expensive and there is no requirement for a validated numerical model. Results show significant potential benefits and a clear evolution of risk. They also show clear need for extending SHM toward creating improved predictive models for analysis of subsequent events, where the Christchurch series of 2010-2011 had significant post-event aftershocks after each main event. Finally, the overall method is generalisable to any typical engineering demand parameter.

2015 - Engineering Bridge Challenge Photograph 15

Images, UC QuakeStudies

A photograph of four students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 13

Images, UC QuakeStudies

A photograph of three students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 24

Images, UC QuakeStudies

A photograph of seven students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 20

Images, UC QuakeStudies

A photograph of six students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 18

Images, UC QuakeStudies

A photograph of five students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 17

Images, UC QuakeStudies

A photograph of five students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 28

Images, UC QuakeStudies

A photograph of eight students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 23

Images, UC QuakeStudies

A photograph of six students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 26

Images, UC QuakeStudies

A photograph of seven students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 27

Images, UC QuakeStudies

A photograph of seven students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 22

Images, UC QuakeStudies

A photograph of six students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 21

Images, UC QuakeStudies

A photograph of six students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 19

Images, UC QuakeStudies

A photograph of five students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 16

Images, UC QuakeStudies

A photograph of four students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 25

Images, UC QuakeStudies

A photograph of seven students on a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 10

Images, UC QuakeStudies

A photograph of a crowd of students sitting on the bank of the Avon River outside the UCSA building in 2015. The students are gathered to watch the annual Engineering Bridge Challenge event.

Head of firm that designed CTV building accepts responsiblity

Audio, Radio New Zealand

The head of the structural engineering firm that supervised the design of the Canterbury Television building appeared yesterday at the Royal Commission into the Canterbury Earthquakes.

2015 - Engineering Bridge Challenge Photograph 31

Images, UC QuakeStudies

A photograph of eight students falling through a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 32

Images, UC QuakeStudies

A photograph of eight students falling through a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 29

Images, UC QuakeStudies

A photograph of eight students falling through a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

2015 - Engineering Bridge Challenge Photograph 30

Images, UC QuakeStudies

A photograph of eight students falling through a bridge they have constructed across the Avon River, outside the UCSA building. The photograph was taken in 2015 during the annual Civil Engineering Bridge Challenge event.

UC Civil and Natural Resources Engineering Photograph 106

Images, UC QuakeStudies

A photograph of a bookcase in the Civil Suite at the University of Canterbury after the 4 September 2010 earthquake. The photograph was taken on the day when the staff were allowed to return to the building. The shelves of the bookcase have been removed, exposing damage along the sides where they knocked against the back panel. Some books have been left on the bottom shelf.

Feasibility of pinned-base connections for demountable precast frame build…

Research papers, University of Canterbury Library

In recent Canterbury earthquakes, structures have performed well in terms of life safety but the estimated total cost of the rebuild was as high as $40 billion. The major contributors to this cost are repair/demolition/rebuild cost, the resulting downtime and business interruption. For this reason, the authors are exploring alternate building systems that can minimize the downtime and business interruption due to building damage in an earthquake; thereby greatly reducing the financial implications of seismic events. In this paper, a sustainable and demountable precast reinforced concrete (RC) frame system in which the precast members are connected via steel tubes/plates or steel angles/plates and high strength friction grip (HSFG) bolts is introduced. In the proposed system, damaged structural elements in seismic frames can be easily replaced with new ones; thereby making it an easily and quickly repairable and a low-loss system. The column to foundation connection in the proposed system can be designed either as fixed or pinned depending on the requirement of strength and stiffness. In a fixed base frame system, ground storey columns will also be damaged along with beams in seismic events, which are to be replaced after seismic events; whereas in a pin base frame only beams (which are easy to replace) will be damaged. Low to medium rise (3-6 storey) precast RC frame buildings with fixed and pin bases are analyzed in this paper; and their lateral capacity, lateral stiffness and natural period are scrutinized to better understand the pros and cons of the demountable precast frame system with fixed and pin base connections.

Geotechnical aspects of the Mw6.2 2011 Christchurch New Zealand Earthquake

Research papers, University of Canterbury Library

The 22 February 2011, Mw6.2 Christchurch earthquake is the most costly earthquake to affect New Zealand, causing an estimated 181 fatalities and severely damaging thousands of residential and commercial buildings. This paper presents a summary of some of the observations made by the NSF-sponsored GEER Team regarding the geotechnical/geologic aspects of this earthquake. The Team focused on documenting the occurrence and severity of liquefaction and lateral spreading, performance of building and bridge foundations, buried pipelines and levees, and significant rockfalls and landslides. Liquefaction was pervasive and caused extensive damage to residential properties, water and wastewater networks, high-rise buildings, and bridges. Entire neighborhoods subsided, resulting in flooding that caused further damage. Additionally, liquefaction and lateral spreading resulted in damage to bridges and to stretches of levees along the Waimakariri and Kaiapoi Rivers. Rockfalls and landslides in the Port Hills damaged several homes and caused several fatalities.

The continued response of the New Zealand Government to the Canterbury ear…

Research papers, University of Canterbury Library

The Canterbury earthquakes of 2010 and 2011 caused significant damage and disruption to the city of Christchurch, New Zealand. A Royal Commission was established to report on the causes of building failure as a result of the earthquakes as well as look at the legal and best-practice requirements for buildings in New Zealand Central Business Districts. The Royal Commission made 189 recommendations on a variety of matters including managing damaged buildings after an earthquake, the adequacy of building codes and standards, and the processes of seismic assessments of existing buildings to determine their earthquake vulnerability. In response the Ministry of Business, Innovation and Employment, the agency responsible for administering building regulation in New Zealand, established a work programme to assist with the Canterbury rebuild and to implement the lessons learned throughout New Zealand. The five primary work streams in the programme are: • Facilitating the Canterbury Rebuild • Structural Performance and Design Standards • Geotechnical and structural guidance • Existing Building Resilience • Post Disaster Building Management This paper provides more detail on each of the work streams. There has been significant collaboration between the New Zealand Government and the research community, technical societies, and engineering consultants, both within New Zealand and internationally, to deliver the programme and improve the resilience of the New Zealand built environment. This has presented major challenges for an extremely busy industry in the aftermath of the Canterbury earthquakes. The paper identifies the items of work that have been completed and the work that is still in progress at the time of writing.