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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The magnitude Mw7.8 ‘Kaikōura’ earthquake occurred shortly after midnight on 14 November 2016. This paper presents an overview of the geotechnical impacts on the South Island of New Zealand recorded during the postevent reconnaissance. Despite the large moment magnitude of this earthquake, relatively little liquefaction was observed across the South Island, with the only severe manifestation occurring in the young, loose alluvial deposits in the floodplains of the Wairau and Opaoa Rivers near Blenheim. The spatial extent and volume of liquefaction ejecta across South Island is significantly less than that observed in Christchurch during the 2010-2011 Canterbury Earthquake Sequence, and the impact of its occurrence to the built environment was largely negligible on account of the severe manifestations occurring away from the areas of major development. Large localised lateral displacements occurred in Kaikōura around Lyell Creek. The soft fine-grained material in the upper portions of the soil profile and the free face at the creek channel were responsible for the accumulation of displacement during the ground shaking. These movements had severely impacted the houses which were built close (within the zone of large displacement) to Lyell Creek. The wastewater treatment facility located just north of Kaikōura also suffered tears in the liners of the oxidation ponds and distortions in the aeration system due to ground movements. Ground failures on the Amuri and Emu Plains (within the Waiau Valley) were small considering the large peak accelerations (in excess of 1g) experienced in the area. Minor to moderate lateral spreading and ejecta was observed at some bridge crossings in the area. However, most of the structural damage sustained by the bridges was a result of the inertial loading, and the damage resulting from geotechnical issues were secondary.
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.
Previous earthquakes demonstrated destructive effects of soil-structure interaction on structural response. For example, in the 1970 Gediz earthquake in Turkey, part of a factory was demolished in a town 135 km from the epicentre, while no other buildings in the town were damaged. Subsequent investigations revealed that the fundamental period of vibration of the factory was approximately equal to that of the underlying soil. This alignment provided a resonance effect and led to collapse of the structure. Another dramatic example took place in Adapazari, during the 1999 Kocaeli earthquake where several foundations failed due to either bearing capacity exceedance or foundation uplifting, consequently, damaging the structure. Finally, the Christchurch 2012 earthquakes have shown that significant nonlinear action in the soil and soil-foundation interface can be expected due to high levels of seismic excitation and spectral acceleration. This nonlinearity, in turn, significantly influenced the response of the structure interacting with the soil-foundation underneath. Extensive research over more than 35 years has focused on the subject of seismic soil-structure interaction. However, since the response of soil-structure systems to seismic forces is extremely complex, burdened by uncertainties in system parameters and variability in ground motions, the role of soil-structure interaction on the structural response is still controversial. Conventional design procedures suggest that soil-structure interaction effects on the structural response can be conservatively ignored. However, more recent studies show that soil-structure interaction can be either beneficial or detrimental, depending on the soil-structure-earthquake scenarios considered. In view of the above mentioned issues, this research aims to utilise a comprehensive and systematic probabilistic methodology, as the most rational way, to quantify the effects of soil-structure interaction on the structural response considering both aleatory and epistemic uncertainties. The goal is achieved by examining the response of established rheological single-degree-of-freedom systems located on shallow-foundation and excited by ground motions with different spectral characteristics. In this regard, four main phases are followed. First, the effects of seismic soil-structure interaction on the response of structures with linear behaviour are investigated using a robust stochastic approach. Herein, the soil-foundation interface is modelled by an equivalent linear cone model. This phase is mainly considered to examine the influence of soil-structure interaction on the approach that has been adopted in the building codes for developing design spectrum and defining the seismic forces acting on the structure. Second, the effects of structural nonlinearity on the role of soil-structure interaction in modifying seismic structural response are studied. The same stochastic approach as phase 1 is followed, while three different types of structural force-deflection behaviour are examined. Third, a systematic fashion is carried out to look for any possible correlation between soil, structural, and system parameters and the degree of soil-structure interaction effects on the structural response. An attempt is made to identify the key parameters whose variation significantly affects the structural response. In addition, it is tried to define the critical range of variation of parameters of consequent. Finally, the impact of soil-foundation interface nonlinearity on the soil-structure interaction analysis is examined. In this regard, a newly developed macro-element covering both material and geometrical soil-foundation interface nonlinearity is implemented in a finite-element program Raumoko 3D. This model is then used in an extensive probabilistic simulation to compare the effects of linear and nonlinear soil-structure interaction on the structural response. This research is concluded by reviewing the current design guidelines incorporating soil-structure interaction effects in their design procedures. A discussion is then followed on the inadequacies of current procedures based on the outcomes of this study.
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.