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Images for Seismicity; more images...

Images, eqnz.chch.2010

The faultline cuts across Telegraph Road, leaving a kink in its originally straight alignment; aftermath of the magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

This originally straight farm fence has been laterally displaced at least 2 metres where it crosses the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.

Images, eqnz.chch.2010

This originally straight farm fence has been laterally displaced at least 2 metres where it crosses the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

This originally straight farm fence has been laterally displaced at least 3 metres where it crosses the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

This originally straight farm fence has been laterally displaced at least 2 metres where it crosses the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Collapsed silos at David Bell Daffodil Farm in Leeston; aftermath of the magnitude 7.1 earthquake that struck mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

The faultline cuts across Telegraph Road, leaving a kink in its originally straight alignment; aftermath of the magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

On the previously unknown faultline on Highfield Road in mid-Canterbury! This was where two tectonic plates slipped, causing the magnitude 7.1 earthquake on Saturday 4 September 2010.

Images, eqnz.chch.2010

The faultline cuts across Telegraph Road, leaving a kink in its originally straight alignment; aftermath of the magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Efforts are being made to shore up and strengthen this building (corner of Hereford Street / Manchester Street) to save it from demolition after it suffered structural damage in the magnitude 7.1 earthquake that struck Christchurch on Saturday 4 September 2010.

Images, eqnz.chch.2010

Slipping of the tectonic plates caused tension cracks on this previously unknown faultline that runs through this paddock; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

This originally straight farm fence has been laterally displaced at least 2 metres where it crosses the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.

Images, eqnz.chch.2010

This originally straight farm fence has been laterally displaced at least 2 metres where it crosses the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.

Images, eqnz.chch.2010

Looking along this previously unknown faultline that runs through this paddock, note how the ground had heaved and subsided; magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

The faultline cuts across Telegraph Road, leaving a kink in its originally straight alignment; aftermath of the magnitude 7.1 earthquake in mid-Canterbury on Saturday 4 September 2010.

Images, eqnz.chch.2010

Falling gable of the Anglican Community of the Sacred Name building left a gaping hole in the roof in the magnitude 7.1 earthquake that hit Christchurch on 4 September 2010. The chimney would have toppled as well had it not been braced.

Research papers, The University of Auckland Library

The 2011, 6.3 magnitude Christchurch earthquake in New Zealand caused considerable structural damage. It is believed that this event has now resulted in demolition of about 65-70% of the building stock in the Central Business District (CBD), significantly crippling economic activities in the city of Christchurch. A major concern raised from this event was adequacy of the current seismic design practice adopted for reinforced concrete walls due to their poor performance in modern buildings. The relatively short-duration earthquake motion implied that the observed wall damage occurred in a brittle manner despite adopting a ductile design philosophy. This paper presents the lessons learned from the observed wall damage in the context of current state of knowledge in the following areas: concentrating longitudinal reinforcement in wall end regions; determining wall thickness to prevent out-of-plane wall buckling; avoiding lap splices in plastic hinge zones; and quantifying minimum vertical reinforcement. http://www.2eceesistanbul.org/

Research papers, The University of Auckland Library

The Canterbury earthquakes in New Zealand caused significant damage to a number of reinforced concrete (RC) walls and subsequent research that has been conducted to investigate the design provisions for lightly reinforced RC walls and precast concrete wall connection details is presented. A combination of numerical modelling and large-scale tests were conducted to investigate the seismic behaviour of lightly RC walls. The model and test results confirmed the observed behaviour of an RC wall building in Christchurch that exhibited a single flexural crack and also raised questions regarding the ability of current minimum reinforcement requirements to prevent the concentration of inelastic deformation at a small number of flexural cracks. These findings have led to changes to the minimum vertical reinforcement limits for RC walls in in the Concrete Structures Standard (NZS 3101:2006), with increased vertical reinforcement required in the end region of ductile RC walls. An additional series of wall tests were conducted to investigate the seismic behaviour of panel-to-foundation connections in singly reinforced precast concrete panels that often lack robustness. Both in-plane and out-of-plane panel tests were conducted to assess both grouted connections and dowel connections that use shallow embedded inserts. The initial test results have confirmed some of the previously identified vulnerabilities and tests are ongoing to refine the connection designs. http://www.aees.org.au/downloads/conference-papers/2015-2/

Research papers, University of Canterbury Library

This poster presents preliminary results of ongoing experimental campaigns at the Universities of Auckland and Canterbury, aiming at investigating the seismic residual capacity of damaged reinforced concrete plastic hinges, as well as the effectiveness of epoxy injection techniques for restoring their stiffness, energy dissipation, and deformation capacity characteristics. This work is part of wider research project which started in 2012 at the University of Canterbury entitled “Residual Capacity and Repairing Options for Reinforced Concrete Buildings”, funded by the Natural Hazards Research Platform (NHRP). This research project aims at gaining a better understanding and providing the main end-users and stakeholders (practitioner engineers, owners, local and government authorities, insurers, and regulatory agencies) with comprehensive evidence-based information and practical guidelines to assess the residual capacity of damaged reinforced concrete buildings, as well as to evaluate the feasibility of repairing and thus support their delicate decision-making process of repair vs. demolition or replacement.

Research papers, University of Canterbury Library

Recent major earthquakes such as Northridge 1994 and Izmit Kocaeli 1999 highlighted the poor performance of existing buildings constructed prior to the early 1970’s. Low lateral seismic design coefficients and the adopted “working stress design” methodology (essentially an elastic design) lacked any inelastic design considerations, thus leading to inadequate detailing. Insufficient development lengths, lapping within potential plastic hinge regions, lack, or total absence of joint transverse reinforcement, and the use of plain round reinforcement and hooked end anchorages were common throughout the structure. The behaviour is generally dominated by brittle local failure mechanisms (e.g. joint or element shear failures) as well as possible soft-storey mechanisms at a global level. Amongst several possible retrofit interventions, a typical solution is to provide the structure with additional structural walls i.e. external buttressing or column in-fills. Extensive developments on precast, post-tensioned, dissipative systems have shown promise for the use of rocking wall systems to retrofit existing poorly detailed frame structures. In this contribution, the feasibility of such a retrofit intervention is investigated. A displacement-based retrofit procedure is developed and proposed, based on targeting pre-defined performance criteria, such as joint shear and/or column curvature deformation limits. A design example, using the proposed retrofit strategy on a prototype frame is presented. A brief overview on experimental work ongoing at the University of Canterbury investigating the dynamic response of advanced rocking walls for retrofit purposes will be provided.

Research papers, The University of Auckland Library

The recent instances of seismic activity in Canterbury (2010/11) and Kaikōura (2016) in New Zealand have exposed an unexpected level of damage to non-structural components, such as buried pipelines and building envelope systems. The cost of broken buried infrastructure, such as pipeline systems, to the Christchurch Council was excessive, as was the cost of repairing building envelopes to building owners in both Christchurch and Wellington (due to the Kaikōura earthquake), which indicates there are problems with compliance pathways for both of these systems. Councils rely on product testing and robust engineering design practices to provide compliance certification on the suitability of product systems, while asset and building owners rely on the compliance as proof of an acceptable design. In addition, forensic engineers and lifeline analysts rely on the same product testing and design techniques to analyse earthquake-related failures or predict future outcomes pre-earthquake, respectively. The aim of this research was to record the actual field-observed damage from the Canterbury and Kaikōura earthquakes of seismic damage to buried pipeline and building envelope systems, develop suitable testing protocols to be able to test the systems’ seismic resilience, and produce prediction design tools that deliver results that reflect the collected field observations with better accuracy than the present tools used by forensic engineers and lifeline analysts. The main research chapters of this thesis comprise of four publications that describe the gathering of seismic damage to pipes (Publication 1 of 4) and building envelopes (Publication 2 of 4). Experimental testing and the development of prediction design tools for both systems are described in Publications 3 and 4. The field observation (discussed in Publication 1 of 4) revealed that segmented pipe joints, such as those used in thick-walled PVC pipes, were particularly unsatisfactory with respect to the joint’s seismic resilience capabilities. Once the joint was damaged, silt and other deleterious material were able to penetrate the pipeline, causing blockages and the shutdown of key infrastructure services. At present, the governing Standards for PVC pipes are AS/NZS 1477 (pressure systems) and AS/NZS 1260 (gravity systems), which do not include a protocol for evaluating the PVC pipes for joint seismic resilience. Testing methodologies were designed to test a PVC pipe joint under various different simultaneously applied axial and transverse loads (discussed in Publication 3 of 4). The goal of the laboratory experiment was to establish an easy to apply testing protocol that could fill the void in the mentioned standards and produce boundary data that could be used to develop a design tool that could predict the observed failures given site-specific conditions surrounding the pipe. A tremendous amount of building envelope glazing system damage was recorded in the CBDs of both Christchurch and Wellington, which included gasket dislodgement, cracked glazing, and dislodged glazing. The observational research (Publication 2 of 4) concluded that the glazing systems were a good indication of building envelope damage as the glazing had consistent breaking characteristics, like a ballistic fuse used in forensic blast analysis. The compliance testing protocol recognised in the New Zealand Building Code, Verification Method E2/VM1, relies on the testing method from the Standard AS/NZS 4284 and stipulates the inclusion of typical penetrations, such as glazing systems, to be included in the test specimen. Some of the building envelope systems that failed in the recent New Zealand earthquakes were assessed with glazing systems using either the AS/NZS 4284 or E2/VM1 methods and still failed unexpectedly, which suggests that improvements to the testing protocols are required. An experiment was designed to mimic the observed earthquake damage using bi-directional loading (discussed in Publication 4 of 4) and to identify improvements to the current testing protocol. In a similar way to pipes, the observational and test data was then used to develop a design prediction tool. For both pipes (Publication 3 of 4) and glazing systems (Publication 4 of 4), experimentation suggests that modifying the existing testing Standards would yield more realistic earthquake damage results. The research indicates that including a specific joint testing regime for pipes and positioning the glazing system in a specific location in the specimen would improve the relevant Standards with respect to seismic resilience of these systems. Improving seismic resilience in pipe joints and glazing systems would improve existing Council compliance pathways, which would potentially reduce the liability of damage claims against the government after an earthquake event. The developed design prediction tool, for both pipe and glazing systems, uses local data specific to the system being scrutinised, such as local geology, dimensional characteristics of the system, actual or predicted peak ground accelerations (both vertically and horizontally) and results of product-specific bi-directional testing. The design prediction tools would improve the accuracy of existing techniques used by forensic engineers examining the cause of failure after an earthquake and for lifeline analysts examining predictive earthquake damage scenarios.