bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary paleoearthquake investigations of active faults on Awaji Island, Japan,  in relation to the 1995 Great Hanshin (Kobe) earthquake
Authors: Van Dissen R. , Begg J. , Awata Y.
Published: January 2020

Approximately one year after the Great Hanshin (Kobe) Earthquake, two New Zealand geologists were invited to help with the Geological Survey of Japan's paleoearthquake/active fault studies in the Kobe/Awaji area. Trenches excavated across the Nojima fault, which ruptured during the Great Hanshin Earthquake, showed evidence of past surface rupture earthquakes, with the age of the penultimate earthquake estimated at approximately 2000 years. A trench across the Higashiura fault, located 3-4 km southeast of the Nojima fault, revealed at least two past surface rupture earthquakes. The timing of the older earthquakes is not yet known, but pottery fragments found in the trench constrain the timing of the most recent earthquake at less than 500-600 years. Historical records for this part of Japan suggest that within the last 700 years there has been only one regionally felt earthquake prior to the 1995 Great Hanshin Earthquake, and this was the AD 1596 Keicho Earthquake. It thus seems reasonable to suggest that the Higashiura fault was, at least in part, the source of the AD 1596 Keicho Earthquake.
Seismic design for torsional response of ductile buildings
Authors: Paulay T.
Published: January 2020

A simple approach to the consideration of torsional effects in the seismic design of ductile building structures is postulated. Instead of increasing torsional strength, the control of twist, which may amplify local inelastic translational deformations, is emphasised. This may be achieved by assuring that some residual torsional stiffness of the system is available. A number of examples illustrate the simple principles involved. It is demonstrated that traditional codified techniques, based on the evaluation of torsional effects in elastic systems, are largely irrelevant to ductile structural response. It is recommended that, in accord with the philosophy of capacity design, torsional response should be controlled by elastic elements, while hysteretic damping is derived from inelastic translational mechanisms. As a general rule critical conditions for torsional response of well proportioned structures are likely to arise only when inelastic displacements are imposed in a narrow band of directions diagonal to the principal reference axes of orthogonal systems. It is suggested that in the presence of significant eccentricities the displacement ductility demand on the system should be reduced. Thereby elements with defined ductility capacity can be protected against excessive imposed inelastic deformations. The presentation addresses primarily concepts of torsional behaviour rather than advancement in analytical techniques.
The fundamentals of an earthquake standard
Authors: King A. B.
Published: January 2020

This paper proposes a rational framework for an earthquake design standard which could be adopted and applied internationally. Initially the standard is expected to be used within New Zealand and Australia as one component within a suite of joint structural standards which would enable design and construction practices to be applied either side of the Tasman. The framework could be easily adopted by other countries because it addresses both inter- and intra- plate earthquakes. Allowance is made for national variations to address varying levels of seismicity and different national performance expectations. The author outlines his views on the objectives and expected contents of the essential elements of an earthquake loading standard which are currently being examined in detail by a Standards Australia and Standards New Zealand working party.
Intraplate seismicity and zonation
Authors: Bolt B. A.
Published: January 2020

Significant intraplate earthquakes have been observed under deep oceans and in all continents except Greenland. They present special problems of seismic risk estimation compared to the more frequent interplate earthquakes. Their location in space and time is more uncertain because of the low seismicity rate, scattered locations, and lack of surface seismogenic fault evidence. Nevertheless, recent geological and seismological work in several stable continents, particularly western North America and Australia, has improved the assessment of seismic hazard maps and risk zonation in such regions. Estimation of robust synthetic ground motion spectra and time histories, however, remains relatively uncertain. Strong motion instrumentation at Continental Reference Stations (CRS) is recommended.
Unreinforced masonry structures
Authors: Page A. W.
Published: January 2020

Unreinforced masonry is widely used in Australia as an architectural and structural material. Because of its high mass, lack of ductility and low tensile strength it is unsuitable for use in areas of high seismicity. However in countries of lower seismicity such as Australia it can be used provided it is designed, detailed and constructed correctly. This paper provides an overview of the use of unreinforced masonry in Australia and discusses the impact of the new seismic loading provisions on existing practice. It is shown that unreinforced masonry can still be used in most instances provided the correct design and detailing techniques are used and the requirements of the appropriate masonry standards implemented.
Displacement-based seismic assessment of existing reinforced concrete buildings
Authors: Priestley M. J. N.
Published: January 2020

Seismic assessment of existing reinforced concrete frame and shear wall buildings is discussed. Building on an earlier preliminary assessment procedure incorporating aspects of capacity design into a systems approach for assessment, suggestions are made towards a displacement-based, rather than forced-based approach to determining available capacity. Based on results from recent experimental programs, procedures are proposed for assessing member strength including column and beam-column joint shear strength, that result in less conservative estimates of performance than would result from application of existing code rules.
The strengthening of Auckland Town Hall
Authors: Robertson T. W.
Published: January 2020

Auckland Town Hall, one of New Zealand's premier heritage buildings, was constructed around 1911 to provide Auckland with a world class concert venue and Civic Centre. Constructed of unreinforced masonry the building does not meet with today's seismic protection standards, particularly as a place of assembly. The owner of the building, Auckland City Council, determined that the building should be strengthened as part of an overall restoration programme. This paper describes the standards of strengthening adopted, the analysis and the strengthening systems utilised and is presented and published with the courtesy of Auckland City Council.
Emergency services review
Authors: Bull David
Published: January 2020

The following is the text of a letter dated 12 September 1996 from the Department of Internal Affairs sent to the Society in reply to our submissions on the government review of Emergency Services.
Observation and synthesis of spatially-incoherentweak-motion wavefields at Alfredton basin, New Zealand
Authors: Haines A. J. , Yu Jaishun
Published: January 2020

To observe and model the detailed pattern of ground motion amplification in a small soft-soil basin an experiment was conducted at Alfredton, New Zealand. 19 seismometers were deployed for 5 weeks at closely spaced sites in and around a 400-500 m diameter, sediment-filled depression in soft, sandstone basement. During this period 112 earthquakes, with "weak" ground motions, were detected by at least some of the instruments, and 15 well-recorded events were selected for detailed analysis. Geotechnical data obtained to provide the parameters for the 3-dimensional modelling included measurements of the shear-wave velocity. Across the basin this is 60 m/s at the surface, increasing steadily to 300+ m/s at the bottom of the basin, and the shear-wave velocity in the basement is 850 m/s. Thus, there are no boundaries where the contrast in shear-wave impedance is especially large. In contrast to situations where there are large contrasts in shear-wave impedance to trap seismic energy in soft-soil layers, the amplifications observed in the basin at Alfredton were small. The small amplifications are confirmed by the 3-dimensional modelling. Another feature of the observed wavefields is that in all cases the incident motions, recorded at the basement sites around the basin, were spatially incoherent. In other words, the wavefields arriving at the basin were of a complex, seemingly random nature. This is the first occasion that the spatial coherency of wavefields has been measured in a fine-scale experiment in New Zealand. Apart from the small amplications and the observed lack of coherency between the basement sites, the most striking result, which was obtained from both the observations and the modelling of similarly incoherent wavefields, is that for short-duration events in which the main motions last for no more than a second, the amplifications in the basin are larger than for events in which the motions are of longer duration; that is, the extent to which differently propagating incoherent wave packets interfere destructively inside the basin increases with the duration of the wavefields.
The city of Los Angeles experience during the 1994 Northridge earthquake
Authors: Quadri N. Delli
Published: January 2020

A successful disaster response depends greatly on how well and how quickly resources can be mobilized and allocated. To do this effectively, there must be a system in place that can collect, prepare and send the resources; and a system at the other end that can effectively receive and deploy them.

The information gained from the Northridge Earthquake and the lesson learned by the City of Los Angeles and its surrounding areas can be of great value to jurisdictions around the world in planning and preparing for future disaster and emergency situations.
Seismic design within architectural education
Authors: Charleson A. W.
Published: January 2020

This paper discusses the teaching of earthquake resistant design within schools of architecture. It aims to stimulate discussion on more effective means of teaching the subject, and to suggest ideas and resources for schools whose seismic design curriculum might benefit from further development.

It is argued that seismic design issues should be included and integrated into architecture curricula. The case is based primarily on observations of building failures resulting from flawed architectural design decisions and subsequent critical reaction from within the architectural profession itself. However, another reason is that the large sizes and restrictive layouts of some seismic load resisting systems impact unavoidably upon architectural layouts.

The content, teaching methods and teaching staff qualities appropriate for a seismic design curriculum are discussed in a case study from the School of Architecture, Victoria University of Wellington. Two key aspects of perceived success are the course's relevance to architectural design and the variety of presentation. Teaching methods, teaching aids and useful references are provided.

The evaluation of the courses considered in the case study is discussed, and postgraduate and post-graduation seismic education in New Zealand is reviewed.
A decade of progress in seismology since the Edgecumbe earthquake
Authors: Smith Euan G. C.
Published: January 2020

During the decade, the contemporaneous increase in data from moderately large earthquakes in New Zealand (and overseas) and the re-equipping of the New Zealand seismograph and accelerograph networks has seen good progress on several fronts. Earthquakes are now more accurately located and their spatial distribution is better defined. There have been improvements in the various databases used for seismic hazard assessments: active faults, earthquake catalogues, historical seismicity, and strong ground motions. The increase in strong-motion data has enabled the development of better models for Peak Ground Acceleration, and the effect of site conditions on site response, particularly for weak-to-moderate earthquake motions, has been studied in detail.
Recent developments in earthquake geotechnical engineering
Authors: Pender M. J.
Published: January 2020

Progress in earthquake geotechnical engineering in the past 10 to 12 years is reviewed. Developments in understanding foundation behaviour and also liquefaction are described briefly. It is explained that perhaps the greatest advance in the period is the interpretation of the substantial amount of site response data which has come to hand. This clarifies earlier controversy about the contribution of nonlinear soil behaviour to site response. Findings show that it is possible for stiff soil sites to behave in a linear manner for quite large peak ground accelerations but for softer soils significant nonlinear response has been inferred using a number of different approaches.
Developments in seismic design procedures for bridges in New Zealand
Authors: Park R.
Published: January 2020

Progress on developments in the seismic design procedures for bridges in New Zealand is outlined. The current approach has evolved from the recommendations of a study group of the New Zealand National Society for Earthquake Engineering which was published in 1980. Research and development into the determination of the design seismic force and ductility demand, the capacity design approach, the detailing of bridge columns for adequate ductility, and the design approach using seismic isolation are discussed. More recent developments in New Zealand involving the assessment and retrofit of older bridge structures are also discussed and likely activities and needs of the next decade are suggested.
A decade of progress since the Edgecumbe earthquake
Authors: Shephard R. Bruce
Published: January 2020

The 2 March 1987 Edgecumbe earthquake of magnitude (ML) 6.3 resulted in a total loss of some NZ$430M and an insured loss of about NZ$330, (non inflation adjusted). Coupled with other world wide natural disasters resulting in large loss costs, particularly insurance costs, the Edgecumbe earthquake contributed to increasing international costs from natural hazards. As well as putting increasing demands on the world insurance markets it also drew attention of insurers to the potential of earthquake loss in New Zealand. With insurance at higher premium rates, and in some situations difficult to obtain cover, there developed increasing demand for loss assessments and risk management applications. The basic development of earthquake loss methodologies had been established in the early 1980's. Developments of the decade following the Edgecumbe earthquake have focused on refinement of these methods, research and collection of data, applications of computer systems, and extensions to other applications.
Lifelines engineering
Authors: Brunsdon David R.
Published: January 2020

Significant developments have occurred in the field of lifelines engineering over the past decade both in New Zealand and internationally. In New Zealand, this period encompassed both the beginnings of lifelines engineering and its development into being an established discipline of earthquake engineering.

This paper charts the progress of lifelines engineering during this time, outlines the key achievements and critical success factors and discusses current needs and future developments.
Vulnerability of different classes of low-rise buildings in the 1987 Edgecumbe, New Zealand, earthquake
Authors: Dowrick David J. , Rhoades David A.
Published: January 2020

This paper describes an analysis of costs of damage to non-domestic buildings (all tow rise) in the Mw = 6.6 Edgecumbe New Zealand earthquake of 2 March 1987. The damage cost for each building was converted to a damage ratio by dividing it by the replacement value of that building. For the MM7 and MM9 intensity zones, the mean values and statistical distributions of these damage ratios were then found, the lognormal distribution fitting the data well. The data was then divided into subsets according to selected classes of construction, and the vulnerabilities of these classes were measured and compared in terms of their mean damage ratios and the associated 95% confidence limits. The classes of building examined included classifications by era of design, number of storeys, materials of construction, and building use. Valuable insights into earthquake resistant design and earthquake risk assessment parameters were obtained through the differences observed between classes, notably significant reductions in the vulnerability of buildings associated with improved ductility provisions.
The Tikokino earthquake of 11 April 1993
Authors: Reyners Martin , McGinty Peter , Ansell Jim , Ferris Brian
Published: January 2020

The nature of faulting that took place during the ML 5.9 Tikokino earthquake of 11 April 1993 has been determined using data from six temporary seismographs installed immediately after the event. The rupture initiated at 25 km depth, within the thrust zone between the subducted Pacific and overlying Australian plates. The earthquake had surprisingly few aftershocks, but those that did occur define a rupture zone which parallels the plate interface. When combined with the focal mechanism of the mainshock, this rupture zone indicates that the earthquake involved thrusting at the plate interface. The earthquake ruptured unilaterally to the south, and this explains the strong directivity seen in both strong motion accelerograph and seismograph records. Movement of the plate interface during the mainshock did not lead to significant triggering of other earthquakes in the subducted or overlying plates. A plausible explanation for the very few aftershocks is that the rupture initiated at an asperity at the plate interface and then propagated into subducted sediment lying in the conditionally stable frictional field. The nearby ML 6.1 Ashley Clinton earthquake of 1958, which also had a conspicuous absence of aftershocks, may have involved a similar process.
A review of code provisions for torsional seismic effects in buildings
Authors: Paulay T.
Published: January 2020

A series of recent studies of the seismic torsional response of ductile buildings is condensed and extended to serve as a basis for recommendations for possible amendments of the relevant clauses of the current New Zealand loadings standard [1]. It is postulated that the primary seismic design aim, associated with criteria of the ultimate limit state, should address displacement ductility demands and supply, as affected by twisting of the system, rather than torsional strength. Some well-established parameters, such as yield displacement, element and system stiffness, are redefined to enable the inelastic deformation pattern of rigid diaphragms to be simply quantified. The presentation concludes with specific recommendations and corresponding commentaries in a form suitable, with editorial modifications, for possible adoption as codified design requirements. To illustrate both the relevance of the recommendations and their simplicity, two numerical examples, showing the evaluation of the displacement ductility capacity of a model structure, are appended.
The 1855 Wairarapa, New Zealand, earthquake
Authors: Grapes Rodney , Downes Gaye
Published: January 2020

Nearly 200 historical accounts have been examined and analysed in order to determine the effects of the magnitude 8+ 1855 Wairarapa, New Zealand, earthquake. The documents examined include contemporary diaries, letters and journals, newspaper reports and articles, archives, memoranda and reports of the Wellington Provincial Government as well as later reminiscences, extracts from published scientific papers, books and other articles. Other than the published accounts of Sir Charles Lyell, who, in 1856, first recognised the importance of the earthquake as causing the greatest deformation and surface fault rupture then known, there has been no comprehensive account of the effects of the earthquake in the scientific literature until now. Much or the data is presented with extensive quotations from the source material, especially where conflicting accounts on important aspects have been found. All material is analysed with an understanding of the geographical, social and political conditions at the time. The reliability of the material is taken account of so that first-hand accounts, that have been recorded no more than several years after the earthquake, and in which there are no obvious inconsistencies or confusion with other earthquakes, are valued most highly. Using the historical accounts as the primary source of data, but also taking into account the results of more recent geological, geomorphological and seismological investigations of the deformation, many aspects of the earthquake are discussed in detail. These are mainshock magnitude and epicentre; felt intensity distribution: descriptive account of the effects of the mainshock on people (including casualties) and man-made structures by location throughout New Zealand (including a resume of contemporary building techniques): effects on the environment from strong shaking such as fissuring, liquefaction, spreading, subsidence and landslides, and from tectonically produced uplift, subsidence and faulting; biological effects; tsunami and seiche; aftershock occurrence and social response and recovery.
Evidence for temporal clustering of large earthquakes in the wellington region from computer models of seismicity
Authors: Robinson Russell , Benites Rafael , Van Dissen Russ
Published: January 2020

Temporal clustering of large earthquakes in the Wellington region, New Zealand, has been investigated with a computer model that generates long synthetic seismicity catalogues. The model includes the elastic interactions between faults. Faults included in the model, besides the subduction thrust between the Australian and Pacific plates, are segments of the four major strike-slip faults that overlie the plate interface (Wairarapa, Wellington, Ohariu, and Wairau faults). Parameters of the model are adjusted to reproduce the geologically ohserved slip rates of the strike-slip faults. The seismic slip rate of the subduction thrust, which is unknown, is taken as 25% of the maximum predicted by the plate tectonic convergence rate, and its position fixed according to recent geodetic results. For comparison, the model was rerun with the elastic interactions suppressed, corresponding to the usual approach in the calculation of seismic hazard where each fault is considered in isolation. Considering earthquakes of magnitude 7.2 or more ("characteristic" events in the sense that they rupture most of a fault plane). the number of short (0-3 years) inter-event times is much higher with interactions than for the corresponding case without interactions (46% vs. 2% or all inter-event times). This reduces to 9% vs. 2% if the subduction thrust is removed from the models. Paleoseismic studies of the past seismic behaviour of the subduction thrust are clearly needed if the degree of clustering is to be tightly constrained. Although some other aspects of our model can he improved in future, we think that the probability of significant short-term clustering of large events, normally neglected in hazard studies, is very high. This has important implications for the engineering, insurance and emergency response communities.
Post-earthquake building safety  evaluation procedures
Authors: Editor
Published: January 2020

The primary aim of this document is to provide Territorial Authorities with an outline response plan so that safety evaluations of damaged buildings can be activated efficiently and effectively following a major earthquake (or any other disaster which affects buildings). Services such as drainage, water supply and roading are not included within the scope of this document.

Territorial Authorities have the responsibility for providing the planning framework, within which a range of professional groups can operate. These include structural and civil engineers, building inspectors, and loss adjusters.

It is intended that these Building Safety Evaluation Procedures will be adopted by all New Zealand Territorial Authorities to avoid the need for each to formulate their own.

National acceptance of these procedures will also mean that only one set of forms, placards, information management systems, training resources etc. need be prepared. A common standard also makes the use of external inspection resources more practicable.

This document confines its scope to Territorial Authority planning for building damage assessment during the emergency phase of a disaster. Further plans for activities arising in the restoration phase are also required. They include:

definition of structural standards for the repair of damaged buildings

streamlined procedures for building consents

streamlined procedures for resource consents, including debris disposal and land use

transfer of information to insurance firms
Natural disaster
Authors: Gregory Geoff
Published: January 2020

The theme of the seminar, panel discussion and open forum, organised by the EQC and the Insurance Council, was Natural Disaster: Finding, managing, and sharing people and information. Emphasis was placed on the recovery and reconstruction phases, beginning about 10 days after the disaster occurred. To provide a focus for discussion, the scenario chosen was the Great Wellington Earthquake, for which fairly detailed modelling has been done, most notably for the Wellington after the Quake Conference, 1995. (1) The seminar was, in fact, a follow-up to that conference, at which various recommendations for action had been made, such as:

raising public awareness o f the recovery aspects of disasters;  

planning for rebuilding, restoration, or relocation in advance of the disaster occurring so that the stress of immediacy and its effects on decision making are reduced;  

ensuring that homeowners, the insurance and building industries, and owners of businesses and buildings have procedures in place to improve the effectiveness of efforts to restore normalcy to disaster-affected areas.(2)  

The seminar was attended by about 100 participants, representing the insurance industry, territorial local authorities, emergency management/civil defence organisations (both local and central), the building industry, the engineering industry and professional engineering societies, and research organisations.
Aspects of drift and ductility capacity of rectangular cantilever structural walls
Authors: Priestley M. J. N. , Kowalsky M. J.
Published: January 2020

Moment-curvature analyses of cantilever shear walls are used to show that yield curvature, serviceability curvature, and ultimate (damage-control) curvature are insensitive to variations of axial load ratio, longitudinal reinforcement ratio, and distribution of longitudinal reinforcement. The results are used to determine available displacement ductility factors for walls of different aspect ratios and drift limits. It is shown that drift capacity will generally exceed code levels of permissible drift, and that code drift limits will normally restrict, sometimes severely, the design displacement ductility factor.
The dynamic properties of a pumiceous sand
Authors: Marks S. , Larkin T. J. , Pender M. J.
Published: January 2020

The seismic site response analysis of sand deposits requires an understanding of the dynamic properties of the soils involved. Most dynamic soil data available in the literature has been derived for sands which do not contain pumice. Consequently, the relevance of this data to the behaviour of pumice sands is unclear. An extensive experimental investigation of the dynamic response of a pumice sand was therefore undertaken. The liquefaction response obtained from cyclic triaxial tests, and the shear modulus variation with strain amplitude observed in bender element and dynamic torsion tests were examined. The cyclic triaxial test results indicated that the liquefaction response was similar to that observed for quartz sands. However, the low strain shear modulus of the pumice sand was found to be significantly less than that of quartz sands at similar relative densities, and the nonlinear stress-strain behaviour was markedly different from that of other sands, particularly in the mid strain range.
Damage and intensities in the magnitude 7.8 1931 Hawke's Bay, New Zealand, earthquake
Authors: Dowrick David J.
Published: January 2020

This paper is the result of a study of the shallow Mw = 7.8 Hawke's Bay earthquake which occurred in the North Island of New Zealand, 2 February 1931 (UT), and which was the final spur to the production of the first earthquake loadings code in New Zealand issued in 1935. This earthquake was a direct hit on two provincial towns (Napier and Hastings) and was the most damaging in New Zealand's history, causing the most casualties, major fires, and much damage to the built and natural environments. It gives the first overall description of the damage (to the buildings and lifelines) in this major event in modem earthquake engineering terms, and presents the first intensity map for the event determined directly in the Modified Mercalli (MM) scale. The zone which experienced the highest intensity (MM10) was confined to a modest area of onshore land (about 300 km2) above the centre of the rupture surface.
Operational requirements for an earthquake forecasting programme for New Zealand
Authors: Vere-Jones David , Harte David , Kozuch Michael J.
Published: January 2020

This paper reviews considerations attendant on introducing an operational forecasting scheme in New Zealand. A background section summarizes the current views on the scientific basis of earthquake forecasting and the progress of empirical studies on New Zealand data. Further sections examine the likely form and time-scale of earthquake forecasts, technical resources required for different aspects of developing the forecasts, the need to identify and work with users of forecast information, and the protocols and procedures for issuing regular and ad hoc forecasts. The need for integrating the development of a forecasting programme within a coordinated framework of natural hazard mitigation is emphasized.
The seismic behaviour of small reinforced concrete beam-column knee joints
Authors: Megget Leslie M.
Published: January 2020

The majority of research into beam-column knee joints has been conducted with monotonic loading. Many of these joints failed to reach their member moment capacity, especially under opening moments, while a few cyclic knee joint tests have been completed in the United States this decade. This paper describes the cyclic testing of 8 small knee joints designed to the 1995 New Zealand Concrete Standard. In addition two joints designed and detailed to the 1965 N.Z. Concrete Code were also tested. Joints with U-bar anchorages performed better than joints with standard 90 degree hook details on beam and column bars. The current Concrete Standard (NZS3101:1995) designs usually attained their nominal moment capacity in both directions up to and including ductility 4 displacements, but subsequently strengths fell off at higher ductilities. Joints with extra diagonal bars across the inner comer were able to sustain their nominal member strengths to higher ductility levels, especially under opening moments. A maximum horizontal joint shear stress of 0.12 f’c, for knee joints, in ductile frame buildings is recommended, where this limit is 60% of the current NZS3101:1995 Standard recommendation. An approximate 25% degradation of the joint shear stress occurred as displacement ductility factors increased from 1 to 8. The 1960's designed joints behaved poorly, as expected, with joint shear and anchorage failures occurring, in both moment directions, at strength levels below the beam's nominal strength. A maximum joint shear stress of only 0.072 f’c was reached and this fell to about a third of that stress between displacement ductility factors of 1 and 4 under closing moments.
Brief comments on elastic flexibility of reinforced concrete frames  and significance to seismic design
Authors: Priestley M. J. N.
Published: January 2020

It is shown, from analysis of typical reinforced concrete beam sections, that current design practice, which assumes beam stiffness is independent of reinforcement ratio but equal to a constant fraction of gross section stiffness is inappropriate. The analyses indicate that effective beam yield curvature can be considered constant, when non-dimensionalized by beam depth and yield strain, indicating that beam stiffness is proportional to strength. Based on this observation, a simple expression for yield drift of frames is proposed and is calibrated by comparing with results of a large number of beam/column subassemblage experiments. Good agreement is obtained. It is pointed out that current estimates of frame stiffness are generally too high. A consequence is that simple calculations show that the vast majority of frame buildings will be unable to achieve code design ductility levels before exceeding code drift limitations.
Magnitudes of New Zealand earthquakes, 1901-1993
Authors: Dowrick D. J. , Rhoades D. A.
Published: January 2020

Determinations of surface-wave magnitude (Ms) are made on a consistent basis for 202 selected New Zealand earthquakes over the period 1901-1993, including most post-1942 events with local magnitude not less than 6.0 and centroid depth less than 45 km. These determinations have led to a reassessment of magnitudes and locations of some earlier events in the New Zealand Seismological Observatory Catalogue of local magnitudes (ML), in some cases with substantial revisions. The surface-wave magnitudes are compared with local magnitudes and moment magnitudes (Mw), where available, and the relations between these three variables and centroid depth are examined through regression models. The absence of surface-wave observations for some earthquakes allows an upper limit to be placed on their likely moment magnitudes. The analysis shows that estimates of Mw derived from Ms will have a standard error of about 0.15 and Mw derived from ML a standard error of about 0.3.
Counting the cost
Authors: Gregory Geoff
Published: January 2020

The Wellington after the Quake conference, organised by the Earthquake Commission in Wellington in March 1995, sought to answer some of the questions faced by all concerned with the recovery and restoration phases of a major earthquake in a nationally significant city. The papers, which were by a range of international authorities, and the discussions were published later that year, and some copies of the volume are still available from the Earthquake Commission.

Then, in November 1996, the Earthquake Commission and the Insurance Council of New Zealand jointly sponsored a seminar on Natural Hazards: Finding, managing and sharing people and information, and a summary booklet was prepared as a record for those who attended and to inform those who were unable to attend.

This seminar, Counting the Cost: The economic effects of a major earthquake, was again sponsored jointly by the Earthquake Commission and the Insurance Council of New Zealand, with the intention of looking more closely at the economic effects of a major earthquake. It attracted about 200 participants, most coming from the insurance and banking industries, fund and risk managers, and economists in a range of organisations, although there were also representatives from emergency management and civil defence organisations, local and regional councils, and earthquake engineers.

This report on the information presented in the papers and discussions has been prepared to highlight the main conclusions and themes raised, for both the attendees and a wider audience who were unable to be present.
Earthquake engineering in Australia
Authors: Bubb Charles
Published: January 2020

Earthquake Engineering in Australia, as elsewhere, has been formatted in the aftermath of damaging earthquakes. The first Australian Code AS2121-1979 was written and published after the 1968 Meckering WA earthquake. The second AS1170.4 1993 was published after the 1989 Newcastle NSW earthquake. Good quality Building Codes are a necessary basis for sound earthquake resistant designs. Both implementation and enforcement of the codes and sound robust construction in the field are essential for the protection of life and infrastructure. Also essential is the preservation and upgrading of the earthquake database. A study to assist the safer operation of emergency services immediately following damaging earthquakes is proposed.
Station correction analysis for surface-wave magnitudes of New Zealand earthquakes
Authors: Rhoades D. A. , Dowrick D. J.
Published: January 2020

Station terms and standard errors are presented for 345 world-wide stations used in the determination of surface-wave magnitudes of 190 selected New Zealand earthquakes over the period 1901-1993 [1]. These will facilitate the estimation of surface-wave magnitudes of other earthquakes in the New Zealand region. The station terms and the residuals from the linear model used to estimate them are both found to be weakly related to the mean distance from the earthquakes recorded by each station. The horizontal and vertical components at a given site are treated as separate stations. The station term for the horizontal component tends to exceed that for the vertical component at mean distances in the 20°-40° range.
Out-of-plane performance of a partially filled reinforced concrete masonry wall with Ribraft_TM floor
Authors: Singh S.S. , Cooke N. , Bull D.K.
Published: January 2020

This paper presents the results of an experimental investigation by Singh (1998) [1], into the serviceability and strength performance of a full-scale reinforced concrete masonry wall with RibraftTM floor. The wall was C-shaped in plan and was partially grouted. The results show that the masonry wall behaved in a ductile manner, and that response remained elastic to an out-of-plane load of approximately 6 kPa. The wall reached the Ultimate Limit State deflection criterion of 50 mm (2% drift) at a load of 7.6 kPa. The crack and deflection patterns were as predicted by the yield-line theory, which however, provided a conservative estimate of the out-of-plane failure load of 5.0 kPa. The test was halted at a load of 10.7 kPa at which point the main wall had not collapsed and was still being supported by the return walls. The RibraftTM floor behaved elastically, except for a local failure restricted to minor spalling of the wall foundations.
Weak motion attenuation of peak ground acceleration in the North Island, New Zealand
Authors: Pancha Aasha , Taber John
Published: January 2020

Attenuation relations using weak ground motion recordings have been determined using data from the New Zealand National Seismograph Network and several temporary seismograph deployments. Models have been developed for earthquake sources in four regions: the Eastern North Island deep and shallow regions and the Central North Island (CNI) deep and shallow regions. Deep events were those with hypocenters below 33 km. Regression coefficients have been determined using the attenuation models of Joyner and Boore (1981) and Molas and Yamazaki (1995). The anelastic attenuation rates in the Eastern North Island expressions are comparable to that of Joyner and Boore (1981), suggesting that weak motion attenuation can be used to estimate variations in strong motion attenuation. However, the absolute level of the strong-motion attenuation curves greatly differs from those of the weak-motion. The anelastic attenuation rate for the shallow CNI is of the order of two to three times that observed for the Eastern North Island. The lowest attenuation rate was found for events within the deep CNI, whose ray paths did not cross the shallow Central North Island region. This is consistent with a low rate of attenuation in the subducting Pacific plate. Azimuthal dependence of PGA is evident within each of the regions. Within the Eastern North Island, the attenuation rate is lowest in the direction of 35-55° from North, which is roughly along the strike of the subducting Pacific plate. A similar azimuthal dependence was also noted within the deep CNI region, while a slightly different minimum direction (5°) was determined for the shallow CNI region.
A model for the attenuation of peak ground acceleration in New Zealand earthquakes based on seismograph and accelerograph data
Authors: Cousins W. J. , Zhao J. X. , Perrin N. D.
Published: January 2020

A combination of weak-motion velocity data from seismographs and strong-motion acceleration data from accelerographs has been used to model the attenuation of peak ground acceleration (PGA) in New Zealand earthquakes. The resulting model extends the PGA attenuation model of Zhao, Dowrick and McVerry [30] to include the variability of rock strength, and also describes the unusually high attenuation in the volcanic zone of the North Island of New Zealand. Strong-rock sites were found to experience lower PGAs than either weak rock or soil sites for magnitudes below Mw 7, and the apparent degree of amplification on going from strong rock to weak rock or soil decreased as the magnitude increased from Mw 5 to Mw 7. At magnitude 7 the PGAs were very similar for all site classes for source distances up to 100 km. When extrapolated to magnitudes beyond the maximum of the data, Mw 7.4, the model predicted that PGAs for strong rock sites were greater than for weak rock or soil sites. The so-called "whole Taupo Volcanic Zone" was found to provide a good boundary for the zone of high attenuation in the volcanic region of the North Island. The high attenuation was successfully modelled as a simple function of the length of travel path through the zone of high attenuation. Over the effective maximum volcanic path length of about 70 km the extra attenuation resulted in a factor of ten reduction in PGA compared with non-volcanic paths of the same length.
The 1934 Pahiatua earthquake sequence
Authors: Downes Gaye , Dowrick David , Smith Euan , Berryman Kelvin
Published: January 2020

Descriptive accounts and analysis of local seismograms establish that the epicentre of the 1934 March 5 Ms7.6 earthquake, known as the Pahiatua earthquake, was nearer to Pongaroa than to Pahiatua. Conspicuous and severe damage (MM8) in the business centre of Pahiatua in the northern Wairarapa led early seismologists to name the earthquake after the town, but it has now been found that the highest intensities (MM9) occurred about 40 km to the east and southeast of Pahiatua, between Pongaroa and Bideford. Uncertainties in the location of the epicentre that have existed for sixty years are now resolved with the epicentre determined in this study lying midway between those calculated in the 1930's by Hayes and Bullen.

Damage and intensity summaries and a new isoseismal map, derived from extensive newspaper reports and from 1934 Dominion Observatory "felt reports", replace previous descriptions and isoseismal maps. A stable solution for the epicentre of the mainshock has been obtained by analysing phase arrivals read from surviving seismograms of the rather small and poorly equipped 1934 New Zealand network of twelve stations (two privately owned). The addition of some teleseismic P arrivals to this solution shifts the location of the epicentre by less than 10 km. It lies within, and to the northern end of, the MM9 isoseismal zone. Using local instrumental data larger aftershocks and other moderate magnitude earthquakes that occurred within 10 days and 50 km of the mainshock have also been located. Approximate locations of other associated moderate magnitude earthquakes until October 1934 have been identified by their maximum intensity and S-P intervals read from the Wellington Wood-Anderson seismograph records. The distribution of S-P intervals of aftershocks (magnitudes M > 3.5) within 24 hours of the mainshock is used to delineate the probable mainshock rupture zone.

Neither contemporary sources nor recent inquiries directed to old residents yield historical evidence of a surface fault rupture. Nevertheless, the strike-slip mechanism at 20 km depth determined by preliminary teleseismic body wave modelling of Doser and Webb suggests that rupture could have extended to the surface. Recent investigation of two of the freshest-looking, active faults that lie within the MM9 isoseismal by Schermer and others indicates that one of them could have ruptured in the 1934 Pahiatua earthquake.
A report on the Relief Organisation in Hastings arising out of the [Magnitude 7.8] earthquake in Hawke's Bay [New Zealand] on February 3, 1931
Authors: Scott Edwin F. , Dowrick D. J.
Published: January 2020

At the time of the 1931 Hawke's Bay earthquake, 33 years old Edwin (Ted) Scott was employed as a civil engineer by the Christchurch Drainage Board. He was also a member of the Christchurch metropolitan emergency committee. In those two capacities he was sent to observe and report on the restoration of services in Hastings, where his father happened to be the municipal Electrical Engineer. He completed this report back in Christchurch, dated 24 April 1931. He later became Chief Engineer of the Christchurch Drainage Board.

The report is very well written giving detailed information on the immediate emergency response period in one of the worst affected towns, Hastings, where the intensity was Modified Mercalli X. This report is complementary to the overview paper on damage and intensities in the Hawke's Bay earthquake by Dowrick [1]. Scott's report contains much that is of value in planning response to future Civil Defence emergencies in New Zealand and elsewhere.

The report discusses the scale of the emergency in Hastings, the setting up of committees, dealing with the dead and injured, the roles of the Police, essential services (including lifelines), food supplies, and the work of the Citizens' Committee which steered and co-ordinated all of the emergency work on behalf of the community.

Apart from omitting the detail of some forms and certificates developed in the emergency. Scott's report is reproduced here in full. The few editorial additions and amendments, made for clarity, are given in square brackets.
Analytical modelling of infilled frame structures
Authors: Crisafulli Francisco J. , Carr Athol J. , Park Robert
Published: January 2020

The analytical modelling of infilled frames is a complex issue because these structures exhibit a highly non- linear inelastic behaviour resulting from the interaction of the masonry infill panel and the surrounding frame. This paper presents a general review of the different procedures used for the analysis of infilled frames, which can be grouped in local or micro-models and simplified or macro-models, depending on the degree of refinement used to represent the structure. The finite element formulation and the equivalent truss mechanism are the typical examples of each group. The advantages and disadvantages of each procedure are pointed out, and practical recommendations for the implementation of the different models are indicated.
The Chi-Chi, Taiwan earthquake of 21 September 1999
Authors: Brunsdon D.R. , Davey R. A. , Graham C. J. , Sidwell G. K. , Villamor P. , White R. H. , Zhao J. X.
Published: January 2020

This report on the 21 September 1999 Taiwan earthquake describes the event and its impacts, along with the observations of the New Zealand Society for Earthquake Engineering Reconnaissance Team. The report covers the effects of the earthquake on the ground, lifelines, buildings, bridges, other structures and the community. The emergency management response is outlined, along with the response of the earthquake engineering community. Lessons for New Zealand are presented and discussed.