Performance of engineered timber structures in the Canterbury earthquakes

2011 ◽  
Vol 44 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Andrew Buchanan ◽  
David Carradine ◽  
Justin Jordan
Keyword(s):  
New Zealand ◽  
Structural Damage ◽  
Lateral Spreading ◽  
Life Safety ◽  
Timber Structures ◽  
Ground Acceleration ◽  
Different Types ◽  
Vertical Ground ◽  
Short Time ◽  
Water Tanks

The September 2010 and February 2011 earthquakes in Canterbury, New Zealand resulted in significant ground excitations that caused severe geotechnical effects and widespread structural damage. This paper outlines the various forms of damage to different types of engineered timber structures, including timber water tanks. Most of the damage resulted from lateral spreading and high levels of horizontal and vertical ground acceleration. The response of these building types is discussed. Engineered timber structures generally performed well both for life safety and serviceability, with most buildings ready for occupation within a short time following the events.

Performance of houses during the Christchurch earthquake of 22 February 2011

2011 ◽  
Vol 44 (4) ◽  
pp. 342-357 ◽  
Author(s):  
Andrew Buchanan ◽  
David Carradine ◽  
Graeme Beattie ◽  
Hugh Morris
Keyword(s):  
Structural Damage ◽  
Lateral Spreading ◽  
Timber Frame ◽  
House Construction ◽  
Wide Range ◽  
Frame Buildings ◽  
Different Types ◽  
Vertical Ground ◽  
High Level ◽  
Very High

The earthquake on 22 February 2011 was very close to Christchurch city, generating very high level ground excitations that caused severe geotechnical effects and widespread structural damage. This paper outlines the wide range of damage to houses resulting from liquefaction, lateral spreading, rockfall, and horizontal and vertical ground accelerations. The response of typical forms of house construction and structural components are discussed, with many different types of damage described. The majority of houses in the Christchurch region are one or two storey light timber frame buildings. This type of construction has performed extremely well for life safety, but thousands of houses have some degree of structural or non-structural damage. The New Zealand Building Code needs to be reviewed in several areas, especially the requirements for foundations and reinforced concrete floors.

scholarly journals Geotechnical aspects of the 2016 Kaikōura earthquake on the South Island of New Zealand

2017 ◽  
Vol 50 (2) ◽  
pp. 117-141 ◽  
Author(s):  
Mark E. Stringer ◽  
Sarah Bastin ◽  
Christopher R. McGann ◽  
Claudio Cappellaro ◽  
Maya El Kortbawi ◽  
...  
Keyword(s):  
New Zealand ◽  
Structural Damage ◽  
Lateral Spreading ◽  
The South ◽  
Alluvial Deposits ◽  
Ground Shaking ◽  
Lateral Displacements ◽  
Oxidation Ponds ◽  
Kaikoura Earthquake ◽  
The Impact

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 post-event 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.

Edgecombe earthquake

1987 ◽  
Vol 20 (3) ◽  
pp. 201-249 ◽  
Author(s):  
M. J. Pender ◽  
T. W. Robertson
Keyword(s):  
Structural Damage ◽  
Ground Surface ◽  
Strong Motion ◽  
Normal Fault ◽  
Lateral Spreading ◽  
Ground Acceleration ◽  
Paper Mills ◽  
North West ◽  
The North ◽  
The Town

On March 2 1987, at 01h 42m 34s UT an earthquake of magnitude (ML) 6.3 occurred near 37.91°S, 176.79°E close to the town of Edgecumbe in the North Island, New Zealand. The depth is provisionally estimated to be 12 ± 1 km. Seismic activity in the general area during the previous week culminated in a foreshock on March 2 of ML 5.2 at 01h 35m 37s. Four aftershocks with magnitudes in excess of 5.0 occurred on March 2 at 01h 51m 08s (ML 5.6), 02h 07m 23s (ML 5.1), 06h 56m 32s (ML 5.2) and 07h 55m 09s (ML 5.2). The earthquakes occurred at the end of summer after a long period of dry weather. Modified Mercalli Intensities of MM IX have been reported in and around Edgecumbe, with possible instances of MM X. Strong motion accelerographs recorded peak ground acceleration of up to 0.33 g within 15 km of the epicentre. The main shock produced a complex series of surface scarps, the longest being about 7 km long striking SW from Edgecumbe. About 1.3 m maximum extension occurred across the scarp with the area to the north-west being downthrown by about a maximum of 1.5 m which continued to subside slowly. Other smaller normal fault traces have also been detected as well as compressional rolls. There was extensive evidence of level ground liquefaction and lateral spreading near rivers. Both these phenomena produced eruption of sands at the ground surface. Some wells were observed to have increased flows or increased pressures whilst others were had decreased flows. General regional subsidence of the alluvial plains in the area up to 2m has been confirmed by levelling completed within three weeks of the earthquake. Structural damage was confined to the alluvial plains in which the town of Edgecumbe is centred. The depth of sediments on the plains is not less than 350 m. There was extensive minor damage to roads. Severe damage to many houses and other single storey structures. A dairy factory complex in Edgecumbe, two paper mills in Kawerau and a paperboard mill in Whakatane all sustained damage, in some cases considerable. At present information on the damage in the paper mills is not available.

Seasonal wound presence and susceptibility to Neonectria ditissima infection in New Zealand apple trees

2015 ◽  
Vol 68 ◽  
pp. 250-256 ◽  
Author(s):  
N.T. Amponsah ◽  
M. Walter R.M. Beresford ◽  
R.W.A. Scheper
Keyword(s):  
New Zealand ◽  
Artificial Inoculation ◽  
Early Winter ◽  
Leaf Fall ◽  
Apple Orchards ◽  
Apple Trees ◽  
Leaf Scar ◽  
Fruit Thinning ◽  
Different Types

Leaf scar wounds are important sites for Neonectria ditissima infection of apple trees Monitoring leaf fall in Scilate/Envy and Braeburn trees to estimate leaf scar wound presence showed maximum leaf scar incidence occurred in June (early winter) Wounds detected in New Zealand apple orchards were bud scale scars fruit thinning and picking wounds leaf scars and pruning cuts Picking wounds are caused during harvest where the pedicel is detached from the shoot Susceptibility of these different types of wounds was determined using artificial inoculation of N ditissima conidia during the season Pruning cut wounds were the most susceptible followed by fruit picking and thinning wounds and the least susceptible were leaf scar wounds No infections were observed when bud scale wounds were inoculated There was no difference in wound susceptibility between cultivars but overall Scilate/Envy wounds developed more lesions than Braeburn wounds

Seismic microzoning in New Zealand

1971 ◽  
Vol 4 (1) ◽  
pp. 43-50
Author(s):  
W. R. Stephenson
Keyword(s):  
New Zealand ◽  
Structural Damage ◽  
Seismic Waves ◽  
Multiple Reflection ◽  
Ground Failure ◽  
Seismic Microzoning ◽  
Popular View ◽  
Wave Trains ◽  
Local Geology ◽  
Ground Damage

"Seismic Microzoning" means many different things to different people. There is always included the element of different damage in nearby areas, but how the differences arise, how we should study them, and how we should apply the results of our studies, are still uncertain. To some people, microzoning refers to structural damage due to ground failure; faulting, slumping and liquefaction all belong in this category. To others, microzoning is the effects of the focussing of seismic waves by boundaries, resulting in modified ground damage and building damage. A third very popular view of microzoning holds that it concerns multiple reflection of seismic waves in layers, with interference of the wave trains giving rise to maxima, where ground and structural damage will be accentuated. Microzoning can be defined as the division of land areas into small regions of differing local geology for which differences in earthquake attack on structures are specified. This paper is an attempt to set down aspects of microzoning in a logical manner, and to relate them. It also discusses activities here and overseas, and considers where microzoning and microzoning research in New Zealand should head.

The Lima earthquake of October 3, 1974: Damage distribution

1977 ◽  
Vol 67 (5) ◽  
pp. 1441-1472
Author(s):  
R. Husid ◽  
A. F. Espinosa ◽  
J. de las Casas
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Concrete Structures ◽  
Effective Length ◽  
Reinforced Concrete Structures ◽  
Severe Damage ◽  
Original Design ◽  
Reinforced Masonry ◽  
Water Tanks ◽  
Story Building

abstract The October 3, 1974, earthquake caused severe damage to buildings of adobe and quincha construction, and also to masonry, reinforced masonry, and reinforced-concrete structures in Lima and vicinity. Most of the damage to well-built structures was due, in part, to the lack of lateral resistance in the original design and to the fact that this earthquake had more energy around 0.4 seconds period than prior destructive earthquakes. Water tanks on the roofs of structures with four or five stories were damaged. Well-engineered single-story buildings were less affected than taller structures. Considerable structural damage to reinforced-concrete structures occurred in the districts of Barranco, La Campiña Molina, and Callao. In La Campiña three-story building partly collapsed and other buildings sustained considerable damage. In La Molina, the buildings of the Agrarian University sustained severe damage, and some collapsed. In Surco, the district adjacent to La Molina, there was no appreciable damage. In Callao, a four-story building collapsed, and the upper half of a concrete silo collapsed. In reinforced-concrete structures, column ties were frequently small in diameter, widely spaced, and not well connected. Usually, the reinforcement of resisting elements had no relation to their stiffnesses. Front columns in school buildings were restrained by high brick walls and had rather short effective lengths to allow building displacement in that direction. The windows in the rear walls gave the rear columns a much greater effective length. Therefore, a longitudinal displacement induces large shear forces in the front columns where most of the severe damage occurred. This problem was not considered in the design of these structures.

scholarly journals New Zealand children’s experiences of online risks and their perceptions of harm. Evidence from Ngā taiohi matihiko o Aotearoa – New Zealand Kids Online

2020 ◽  
Author(s):  
Edgar Pacheco ◽  
Neil Melhuish
Keyword(s):  
New Zealand ◽  
Quantitative Study ◽  
Research Report ◽  
Public Discussion ◽  
Representative Data ◽  
Aotearoa New Zealand ◽  
Online Safety ◽  
Different Types ◽  
Support Programmes ◽  
Policy Discussion

While children’s experiences of online risks and harm is a growing area of research in New Zealand, public discussion on the matter has largely been informed by mainstream media’s fixation on the dangers of technology. At best, debate on risks online has relied on overseas evidence. However, insights reflecting the New Zealand context and based on representative data are still needed to guide policy discussion, create awareness, and inform the implementation of prevention and support programmes for children. This research report presents findings from a quantitative study regarding different aspects related to risks and online safety. It looks at the online experiences that children find bothersome and upsetting and explores the hurtful behaviours they encounter or engage in, both online and in person. Evidence regarding exposure to different types of potentially harmful online content is also presented. Another relevant contribution is the insights related to excessive internet use.The findings presented in this report are based on data from 2,061 New Zealand children aged 9-17. We hope the findings will contribute to the development of policies, practices and services designed to support New Zealand children to safely take advantage of the opportunities available to them online.

scholarly journals A Novel Piezoceramic-Based Sensing Technology Combined With Visual Domain Networks for Timber Damage Quantification

2021 ◽  
Vol 8 ◽  
Author(s):  
Haibei Xiong ◽  
Lin Chen ◽  
Cheng Yuan ◽  
Qingzhao Kong
Keyword(s):  
Time Domain ◽  
Damage Assessment ◽  
Structural Damage ◽  
High Efficiency ◽  
Experimental Studies ◽  
Stress Wave Propagation ◽  
Timber Structures ◽  
Sensing Technology ◽  
The Time Domain ◽  
Visual Domain

Early detection of timber damage is essential for the safety of timber structures. In recent decades, wave-based approaches have shown great potential for structural damage assessment. Current damage assessment accuracy based on sensing signals in the time domain is highly affected by the varied boundary conditions and environmental factors in practical applications. In this research, a novel piezoceramic-based sensing technology combined with a visual domain network was developed to quantitatively evaluate timber damage conditions. Numerical and experimental studies reveal the stress wave propagation properties in different cases of timber crack depths. Through the spectrogram visualization process, all sensing signals in the time domain were transferred to images which contain both time and frequency features of signals collected from different crack conditions. A deep neural network (DNN) was adopted for image training, testing, and classification. The classification results show high efficiency and accuracy for identifying crack conditions for timber structures. The proposed technology can be further integrated with a fielding sensing system to provide real-time monitoring of timber damage in field applications.

scholarly journals Time Resolved Emission of Sidestream Smoke Particles

1992 ◽  
Vol 15 (2) ◽  
pp. 53-57
Author(s):  
R Dittmann ◽  
HJ Feld ◽  
BH Müller ◽  
W Schneider
Keyword(s):  
Time Scales ◽  
Time Resolved ◽  
Smoke Particles ◽  
Sidestream Smoke ◽  
Different Types ◽  
Short Time ◽  
Aerosol Properties

AbstractBy means of the dispersion quotient method, the aerosol properties of freshly produced sidestream smoke were measured during the puff and subsequent interpuff period. These measurements were made on short time scales and at high aerosol concentrations. Examples are presented, which show the influence of different combustion conditions during the puff (resulting from different degrees of ventilation and different types of tobacco) on the emission of sidestream particles during the interpuff period. The ratio of the volume concentrations of the particles before and during a puff is reduced by ventilation and is nearly unchanged by the variation of the tobacco type.

scholarly journals Empirical models for predicting lateral spreading and evaluation using New Zealand data

2008 ◽  
Vol 41 (1) ◽  
pp. 10-23 ◽  
Author(s):  
Jian Zhang ◽  
Dick Beetham ◽  
Grant Dellow ◽  
John X. Zhao ◽  
Graeme H. McVerry
Keyword(s):  
New Zealand ◽  
Strong Motion ◽  
Lateral Spreading ◽  
Attenuation Relations ◽  
Geotechnical Parameters ◽  
Ground Shaking ◽  
Aerial Photos ◽  
New Model ◽  
The Difference ◽  
Lateral Displacements

A New empirical model has been developed for predicting liquefaction-induced lateral spreading displacement and is a function of response spectral displacements and geotechnical parameters. Different from the earlier model of Zhang and Zhao (2005), the application of which was limited to Japan and California, the new model can potentially be applied anywhere if ground shaking can be estimated (by using local strong-motion attenuation relations). The new model is applied in New Zealand where the response spectral displacement is estimated using New Zealand strong-motion attenuation relations (McVerry et al. 2006). The accuracy of the new model is evaluated by comparing predicted lateral displacements with those which have been measured from aerial photos or the width of ground cracks at the Landing Road bridge, the James Street loop, the Whakatane Pony Club and the Edgecumbe road and rail bridges sites after the 1987 Edgecumbe earthquake. Results show that most predicted errors (defined as the ratio of the difference between the measured and predicted lateral displacements to the measured one) from the new model are less than 40%. When compared with earlier models (Youd et al. 2002, Zhang and Zhao 2005), the new model provides the lowest mean errors.

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