bluuebunny/crossref_metadata_2025 huggingface dataset:
The Roball
Authors: Robinson William H.
Published: January 2020

Robinson Seismic's latest developments in seismic isolation includes a new device, the RoballTM, for seismically isolating structures during earthquakes. This advance is a new concept for seismic isolation based on the principle of the inverted pendulum. It consists of 'friction balls' or 'Roballs' moving between upper and lower spherical like cavities or flat plates. The Roballs are filled with a material which is able to provide the friction forces required to absorb the energy from numerous earthquakes while supporting the structure. The Roball technique is expected to enable light and in the future possibly heavy structures to be more economically seismically isolated. As part of a program to develop a user friendly 'seismic isolation system' a series of full-scale tests have been carried out on a number of possible designs including three approaches for vertical pressures of -1 MPa resulting in coefficients of friction of -0.1 to -0.4. In this paper we present the preliminary experimental results.
Social and economic consequences of historic caldera unrest at the Taupo volcano, New Zealand and the management of future episodes of unrest
Authors: Johnston David , Scott Brad , Houghton Bruce , Paton Douglas , Dowrick David , Villamor Pilar , Savage John
Published: January 2020

In 1998, changes in a number of indicators (earthquakes and uplift) at two of New Zealand's active volcanic caldera systems (Okataina and Taupo) resulted in increased public, local and central government awareness and some concern about the potential significance of volcanic unrest at a caldera volcano. This paper summarises the episodes of unrest recorded at Taupo caldera since 1895. There have been four significant events (1895, 1922, 1963-64 and 1983) that have included earthquake activity and ground deformation. Caldera unrest is one of the most difficult situations the volcanological and emergency management communities will have to deal with. There is potential for adverse social and economic impacts to escalate unnecessarily, unless the event is managed appropriately. Adverse response to caldera unrest may take the form of the release of inappropriate advice, media speculation, unwarranted emergency declarations and premature cessation of economic activity and community services. A non-volcanic-crisis time provides the best opportunity to develop an understanding of the caldera unrest phenomena, and the best time to establish educational programmes, funding systems for enhanced emergency response and volcano surveillance and to develop co-ordinated contingency plans.
The Wainuiomata "local effects" seismograph network
Authors: Stephenson Bill , Barker Peter , Yu Jiashun
Published: January 2020

The Wainuiomata "local effects" network of 16 seismographs was established and operated during three months of the year 2000. The effectiveness of earlier such networks is discussed, together with the way that the results from the earlier networks influenced the establishment and operation of the Wainuiomata network. An overview is given of the results obtained, together with a sample analysis of one set of seismograms.
Guided Love- and Rayleigh-waves in Parkway Valley, Wainuiomata, N.Z.
Authors: Stephenson W.R. (Bill)
Published: January 2020

A detailed analysis of one earthquake recorded by a dense array of seismographs on the surface of an alluvial valley shows two locally-generated waves which propagate down-valley. The faster travelling one is a Rayleigh wave, and the slower one is similar to a Love wave, but has a vertical component thought to arise from the need to meet lateral boundary conditions. These waves can mimic normal modes, and their interaction provides a basis for explaining directional resonances.
Development of a volcanic hazard model for New Zealand
Authors: Stirling M.W. , Wilson C. J. N.
Published: January 2020

We commence development of a volcanic hazard model for New Zealand by applying the well- established methods of probabilistic seismic hazard analysis to volcanoes. As part of this work we use seismologically-based methods to develop eruption volume - frequency distributions for the Okataina and Taupo volcanoes of the central Taupo Volcanic Zone, New Zealand. Our procedure is to use the geologic and historical record of large eruptions (erupted magma volumes ≥ 0.01 cubic km for Taupo and ≥ 0.5 cubic km for Okataina) to construct eruption volume-frequency distributions for the two volcanoes. The two volcanoes show log-log distributions of decreasing frequency as a function of eruption volume, analogous to the shape of earthquake magnitude-frequency distributions constructed from seismicity catalogues. On the basis of these eruption volume-frequency distributions we estimate the maximum eruption volumes that Taupo and Okataina are capable of producing at probability levels of relevance to engineers and planners. We find that a maximum eruption volume of 0.1 cubic km is expected from Taupo with a 10% probability in 50 years, while Okataina may not produce a large eruption at this probability level. However, at the more conservative 2% probability in 50 years, both volcanoes are expected to produce large eruptions (0.5 cubic km for Okataina and 1 cubic km for Taupo). Our study therefore shows significant differences in eruption probabilities for volcanoes in the same physiographic region, and therefore highlights the importance of establishing unique eruption databases for all volcanoes in a hazard analysis.
Effects of microzoning and foundations on damage ratios for domestic property in the magnitude 7.2 1968 Inangahua, New Zealand earthquake
Authors: Dowrick D.J. , Rhoades D.A. , Davenport P.N.
Published: January 2020

In a recent study the present authors examined the damage ratios for houses and household contents in the Inangahua earthquake for intensities MM5-MM10, including the effects of chimney damage. The present study continues this work by examining the effects of ground class and construction type on damage levels. Houses from six towns are considered, i.e. Inangahua, Reefton, Westport, Greymouth, Runanga and Hokitika, covering a range of intensities from MMl0.5 down to MM7.0. A range of ground classes is also considered, covering the three classes described in the New Zealand loadings standard. The structural types considered comprise two foundation types (piled vs. concrete perimeter wall footings), and number of storeys. Some complexities and difficulties of reliable microzoning are revealed and discussed.
Seismic displacement capacity of ductile reinforced concrete building systems
Authors: Paulay Tom
Published: January 2020

To enable acceptable seismic displacement demands to be estimated, the displacement capacity of a structural system needs to be known. This is controlled by selected performance criteria. It is postulated that the assignment of fractions of the required seismic strength of a system to its components may be arbitrary. This enables the displacement capacity of buildings to be evaluated without the knowledge of the magnitude of seismic strength. A redefinition of some traditionally used structural properties is a prerequisite for applications. The following study of reinforced concrete mixed systems illustrates rationale and extreme simplicity of application.
International visions and goals for the Earthquake Engineering Research Institute
Authors: Poland C.D. , Alcocer S.M.
Published: January 2020

The Earthquake Engineering Research Institute (EERI) has recently added public advocacy for seismic safety to its rich history of facilitating the discussion amongst earthquake scientists and engineers. In recognition of its unique role as the authoritative source for information in the United States, EERI also seeks to partner with other nations to develop information for use worldwide. In 2002, EERI began forming cooperation agreements with organizations in other countries that encourage the exchange of information, collaborative efforts in learning from earthquakes, joint memberships, development of mitigation tools and techniques, and access to seminars, conferences, and technical publications. The ultimate goal of the program is to arrest the growth of seismic vulnerability worldwide and thereby save lives, protect capital investments, and minimize economic impacts.
Seismic design implications of revisions to the National Building Code of Canada
Authors: Heidebrecht A.C.
Published: January 2020

This paper begins with a brief introduction to Canadian seismicity and the history of seismic code development in Canada; a summary of major changes planned for the 2005 edition of the National Building Code of Canada follows. Areas of major change include seismic hazard, site effects, irregularities, force reduction factors and methods of analysis (dynamic analysis now being preferred). The implications of the proposed changes are presented in terms of impact on seismic design force for several structural systems located in regions of high, moderate and low seismicity; implications for seismic level of protection and the seismic design process are also discussed. The paper concludes with a discussion of ongoing seismic code development issues.
Australian earthquake engineering
Authors: Griffith M.C.
Published: January 2020

The Australian Earthquake Engineering Society was established in 1990 with its main objective to promote and advance the practice of earthquake engineering and engineering seismology in Australia. In the decade or so since its establishment the Society has had some successes in this regard as well as some disappointments. In this paper, the author will highlight these along with research and other important professional developments during this period. The perceived obstacles to getting a better take-up of earthquake engineering amongst Australian practitioners and the role of the Society in furthering the cause of earthquake engineering in Australia will then be discussed. The paper will conclude with an outline of possible strategies for overcoming these obstacles.
Challenges for the application of earthquake engineering in the Pacific Islands
Authors: Shorten G.G.
Published: January 2020

Experience has shown that successful application of earthquake engineering in the Pacific, particularly the understanding of earthquake risk as applied in the high-risk urban areas, is fundamentally dependent on continuing studies of seismicity and neotectonics; research on foundation problems; the institution of building standards; and seismic microzonation studies of urban population centres. The whole needs to be carried forward by a comprehensive risk-management approach that takes scientific and engineering advances towards social outcomes by defining the people, buildings and infrastructure at risk, and engages the relevant communities in planning for ways to treat risk, including risk-financing for catastrophes. The challenges inhibiting that successful application in the Pacific Islands are manifold, and include problems imposed from outside the region as well as those inherent from within. The focus of activities related to earthquake engineering should now be on the solutions to those challenges, including improvements in education, organisational approaches and research on the local risk, as well as providing for an immediate technical response capacity to disasters and a regional network facility. Overwhelmingly, a more efficient coordination of the services provided by the international community is called for, because a concerted effort is required if there is to be any chance of successfully overcoming the challenges to sustainable development in the Pacific.
The seismic response of elevated liquid storage tanks isolated by lead-rubber bearings
Authors: Shrimali M.K. , Jangid R.S.
Published: January 2020

The seismic response of elevated liquid storage tanks isolated by the lead-rubber bearing is investigated under real earthquake ground motion. Two types of isolated tank models are considered in which the bearings are placed at the base and top of the tower structure. The tank liquid is modelled as lumped masses referred as convective mass, impulsive mass and rigid mass. The corresponding stiffness associated with these lumped masses has been worked out using the properties of the tank wall and liquid mass based on simple single-degree-of-freedom concepts. The mass of the tower structure is lumped equally at top and bottom. The assembled equations of motion are solved by Newmark's step-by-step method with iteration. The seismic response of two types of tanks, namely slender and broad tanks is obtained and a parametric study is carried out to study the effects of important system parameters on the effectiveness of seismic isolation. The various important parameters considered are the tank aspect ratio, the time period of the tower structure, damping and the lime period of the isolation system. It has been observed that the earthquake response of the isolated tank is reduced significantly. Further, it is observed that the isolation is more effective for the tank with a stiff tower structure in comparison to flexible towers. In addition, a simplified analysis is also presented to evaluate the response of the elevated tanks using a two-degrees-of-freedom model and two single degree-of-freedom models. It is observed that the proposed methods predict accurately the seismic response of elevated liquid storage tanks with less computational efforts.
Some controversial aspects of the seismic design of reinforced concrete building structures
Authors: Park Bob
Published: January 2020

Significant differences exist between the recommendations for seismic design of the codes and guidelines for reinforced concrete of different countries. Performance criteria for building structure to avoid unacceptable damage during various levels of earthquake hazard need to be refined. More accurate recommendation for the effective flexural rigidity of reinforced concrete members are required for linear elastic structural analysis to enable better estimates of the periods of vibration and the lateral deflections of statically indeterminate structures including the effects of cracking of concrete. Current code recommended values for flexural rigidity will generally lead to estimates of the periods of vibration and lateral deflections, which are on the low side. The capacity design approach to ensure the most appropriate mechanism of yielding will occur in the event of a severe earthquake is generally recognized by codes but to varying degrees of clarity, and the degrees to which capacity design is incorporated in each code varies significantly. High strength concrete and high strength non-prestressed steel reinforcement can be used in the design of buildings but the brittle behaviour of high strength concrete and the unusable yield strength of high strength steel reinforcement need to be considered. Important differences between codes exist in the rules for the quantity of confining reinforcement placed in reinforced concrete columns to ensure ductile behaviour. Significant differences also exist between the quantities of shear and confining reinforcement required in beam-column joints and in the anchorage of length of longitudinal reinforcement passing through beam-column joints. Precast concrete structures can be designed successfully for earthquake resistance but design codes in seismic regions contain provisions for precast concrete to varying degrees.
The magnitude 8.3 June 23 2001 southern Peru earthquake and tsunami
Authors: Stirling Mark , Langridge Robert , Benites Rafael , Aleman Hector
Published: January 2020

We present a precis of our reconnaissance trip to the area of the magnitude 8.3 June 23 2001 southern Peru earthquake and tsunami. The trip was undertaken because of the relevance of the event to hazard assessment in New Zealand. It is the best example in nearly 40 years of the maximum-size earthquake that might occur on the Hikurangi subduction zone, an event that is absent from the historical record of New Zealand (since 1840) and therefore of unknown potential in terms of hazard. Despite the great magnitude of this subduction interface earthquake, it produced only "moderately strong" levels of earthquake shaking (peak ground acceleration of 0.3g on alluvium from the one strong motion accelerograph in the earthquake area, and Modified Mercalli Intensity 8 in the epicentral area), and relatively minor ground damage (liquefaction and landslides). It did however produce a large and devastating tsunami. Our comparison of the one accelerograph record and attenuation curves for subduction interface earthquakes shows that the strength of shaking was typical for subduction interface earthquakes. If we apply our observations to New Zealand, they imply that a Hikurangi subduction interface earthquake may be less damaging to built-up areas in the southeastern part of the North Island (e.g. Wellington and Napier/Hastings) than earthquakes on major active faults in the shallow crust. However, the lateral extent of the strongest shaking in a subduction earthquake (300 km for the southern Peru event) and the associated tsunami generation will make the earthquake very significant in the national context.
The implementation of seismic isolation in the retrofit of a large wharf
Authors: Davidson Barry J. , Bell Darrin K. , George Stuart F.
Published: January 2020

The paper describes the implementation of lead-rubber bearings as energy absorbers as part of the retrofit and upgrade of a large wharf. The key design requirement of the seismic retrofit was to ensure that the limited ductility capacity of the existing wharf piles was not exceeded. This was achieved by providing additional lateral restraint to the wharf in the form of groups of raking piles fastened to the wharf via post-tensioned lead-rubber bearings acting as energy absorbers.
The Mw 7.2 Fiordland earthquake of August 21, 2003
Authors: Reyners Martin , McGinty Peter , Cox Simon , Turnbull Ian , O'Neill Tim , Gledhill Ken , Hancox Graham , Beavan John , Matheson Dion , McVerry Graeme , Cousins Jim , Zhao John , Cowan Hugh , Caldwell Grant , Bennie Stewart , GeoNet team
Published: January 2020

The Mw 7.2 Fiordland earthquake of August 21 2003 was the largest shallow earthquake to occur in New Zealand for 35 years. Because of its location in an unpopulated area, it caused only minor damage to buildings, roads and infrastructure. It triggered numerous landslides on steep slopes in the epicentral region, where intensities reached MM9. Deployments of portable seismographs, strong motion recorders and GPS receivers in the epicentral region immediately after the event have established that the earthquake involved thrusting at the shallow part of the subduction interface between the Australian and Pacific plates. Recently installed strong motion recorders of the GeoNet network have ensured that the earthquake is New Zealand's best recorded subduction interface event. Microzonation effects are clear in some of the records. Current peak ground acceleration attenuation relationships for New Zealand subduction interface earthquakes underprediet the ground motions recorded during the earthquake, as was the case for previous large events in Fiordland in 1993 and 1989. The four portable strong motion recorders installed in the epicentral region have provided excellent near-field data on the larger aftershocks, with recorded peak ground accelerations ranging up to 0.28g from a nearby ML 6.1 event.
Earthquake risk reduction actions for New Zealand
Authors: Dowrick David J.
Published: January 2020

This paper discusses what we already do and what extra should be done lo reduce earthquake risk in New Zealand. Some of the needed actions have been learned from the consequences, good as well as bad, of earthquakes that have occurred both in New Zealand and in other parts of the world. A list of 26 weaknesses are identified in New Zealand's systems of earthquake risk reduction. Remedial actions to overcome these weaknesses in a balanced way involve at least nine parties. Fifteen of the weaknesses have five or more parties who could or should take some remedial action over them. Engineers have technical actions to address 20 of the weaknesses, while earthquake-related professions have an advocacy role to play in all of them. The potential exists for reducing earthquake losses by about an order of magnitude, i.e. worth billions of dollars and thousands of casualties in future earthquakes.
Criteria for strengthening buildings
Authors: Smith Warwick
Published: January 2020

Decisions on the merit of strengthening buildings to resist earthquakes should not be made on a cost benefit basis, and in particular should not use estimates of the benefit that are based on the average rate of occurrence of strong ground motion. The distribution of expected ground motion is so skewed that no central measure provides a good representation of the risk. A better procedure is to determine what is the unacceptable level of loss, and then to engineer to the strength that will prevent that loss.
In search of elegance
Authors: Collins M.P.
Published: January 2020

This paper will discuss the evolution of the art of structural engineering by examining examples of elegant structures from the time of the Roman Empire to the present. The evolution of design procedures used by structural engineers will also be discussed.
Does capacity design do the job?
Authors: Priestley M.J.N.
Published: January 2020

Current provisions in the New Zealand Loadings code for dynamic amplification of moment and shear force in cantilever wall buildings are critically examined. Based on time-history analyses of six wall structures, from two- to twenty-storeys, it is found that higher mode effects are inadequately represented by either the equivalent lateral force or modal response spectrum design methods. The time-history results indicate that dynamic amplification is dependent on both initial period, and expected displacement ductility level. Two different methods for consideration of higher mode effects in cantilever walls are proposed. The first is based on a simple modification of the modal response spectrum method, while the second is appropriate for single-mode design approaches such as the equivalent lateral force method. Both are found to give excellent representation of expected response. It is shown that providing capacity protection at the design seismic intensity does not ensure against undesirable failure modes at intensities higher than the design level. This has significance for the design of critical facilities, such as hospitals.
Seismic design of New Zealand houses
Authors: Thurston Stuart J. , Park Stuart G.
Published: January 2020

This paper presents the basis for changing the current test and evaluation procedure used to establish bracing ratings. This is known as the BRANZ P21 test method and is used to obtain the bracing ratings of timber framed wall systems for houses, and other low-rise structures, to meet the wind and seismic demand stipulated in the light timber framing standard, NZS 3604:1999. The demand seismic loads in NZS 3604 were based on the loadings specified in the New Zealand loadings standard, NZS 4203:1992. This paper proposes a revised P21 test seismic evaluation (called EM3) so that houses constructed to NZS3604 do not exceed their wall deformation capacity when analysed against a suite of earthquake records compatible with NZS 4203:1992.
Seismic retrofitting of low strength unreinforced masonry non-engineered school buildings
Authors: Bothara J. K. , Pandey B. , Guragain R.
Published: January 2020

Schools in Nepal, both their buildings and its occupants face extreme risk from earthquakes because of highly vulnerable building stock and high occupancy in it. Further, schools house an entire generation and a community's future so these need special attention. Loss suffered by a community in collapse of a school is psychologically much greater than any other community building.

In 1988 the Udaypur earthquake, which measured 6.6 on the Richter scale, about 950 school buildings incurred damage of different degrees spanning between damage to collapse. A study completed by the Kathmandu Valley Earthquake Risk Management Project in 2000 AD, to explore the seismic vulnerability of school buildings and possible intervention options in Kathmandu Valley, showed a grim situation. This paper explores the methods that were implemented for strengthening existing low strength unreinforced masonry school buildings. A basic emphasis was placed on economic affordability, technical implementation and its adoptability by local craftsmen. The retrofitting design was based on identification of deficiencies, the most critical failure mechanisms, and simple calculations.
A 1983-1993-2003 state-of-the-art report on seismic analysis
Authors: Kelly T.E.
Published: January 2020

A 2003 state-of-the-art report on seismic analysis for structural engineers would be similar to one that could have been produced in 1993 or 1983, and in fact not much different from 1973. Development of structural engineering analysis tools has not kept pace with the rapid improvement in computer hardware.

Our common analysis tools ignore either nonlinearity (response spectrum analysis), dynamic effects (pushover analysis), or both (equivalent static analysis) even though these effects are critical in evaluating the pe1formance of a structure under earthquake loads.

This paper examines the effects of nonlinearity and dynamic loads on the response of structures and illustrates cases where ignoring either of these leads to erroneous results. Given this need for nonlinear dynamic analysis, impediments to more widespread use are discussed and areas where more research information is required are identified.

The conclusion of this paper is that our profession needs to be more active in implementing software development, graduate training in analysis and the processing of research results to a format suited for analysis models. We have a wealth of research information providing detailed response of structural components but, by failing to convert this into detailed rules for nonlinear analysis, we are neglecting much of the value in this research.
Beyond ductility
Authors: Mander John B.
Published: January 2020

Although the precepts of capacity design and detailing for ductile performance are now well established, the end-user community is now demanding more in terms of predictable performance with an expectation that structures should survive earthquakes with minimal and preferably no damage. The paper first explains the shortcomings of present designs from a probabilistic fragility point-of-view, and then goes on to explain how performance can be improved by making a paradigm shift. This paper examines the emerging quest where structural engineering researchers are investigating design alternatives that strive for damage avoidance.
Results of a reconnaissance trip to Mt. Etna, Italy
Authors: Barnard Scott T.
Published: January 2020

This paper details the observations taken from a reconnaissance trip to Mt. Etna, Italy during the 2002 flank eruption, and utilizes those observations to identify potential hazards in New Zealand. It also makes recommendations for preparation and response to those hazards. The various types of hazards posed by Etna are primarily lava flows, ashfall and earthquakes. Lava flows caused intense damage in proximal areas, including forests, roads and the destruction of ski lifts and several buildings. Ashfall affected a much larger area, and was thus responsible for most of the damage economically. While earthquakes were not severe by New Zealand standards, the unreinforced masonry structures that predominate on Etna did not cope well with the seismic activity that accompanied the eruption. Several lessons taken from this eruption are applicable to New Zealand, both in effects of basaltic and more silicic types of volcanism.
Estimating earthquake and landslide tsunami hazard for the New Zealand coast
Authors: Lange W.P. de , Moon V.G.
Published: January 2020

Tsunamis are a significant hazard on the New Zealand coast, with historic events being mostly generated by submarine earthquakes and landslides. Historical data combined with numerical modelling provides the best estimates of potential tsunami behaviour, but requires more data than is normally available for New Zealand. Simple parametric models provide useful estimates of maximum tsunami amplitude for seismic and landslide generation mechanisms, and a viable approach to characterise potential tsunami hazard.
Establishing the linkages between structural engineering and risk management
Authors: Brunsdon D.R.
Published: January 2020

A structural engineering background provides an excellent platform for undertaking a wide range of risk management activities. One of the most valuable and unique skill elements is the ability to visualise damage impacts resulting from earthquake and other natural and man-made hazards.

This paper explores the linkages between structural engineering and risk management. The many activity strands of structural engineering are expressed in terms of the fundamental steps in the risk management process of risk context, risk identification, risk assessment, risk treatment and risk communication. It is concluded that the linkages between the disciplines are more direct than is often appreciated by many structural engineers.

The importance of professional engineers understanding the wider context of their activities is highlighted. This includes awareness of recent legislation beyond the customary building regulatory frameworks, with particular reference to the Civil Defence and Emergency Management Act 2002. One of the changes brought about by this Act is to place greater emphasis on the consequences of hazard events on infrastructure and communities. For engineers, this involves moving beyond identifying the impacts of an event into the area of addressing the community consequences.

Engineers play a key role in risk communication in a variety of different situations. The need for engineers to be proactive advocates to asset owners and operators for a more holistic approach to risk management is emphasised.
Site effects and SPAC. results for three sites in Wainuiomata
Authors: Chavez-Garcia Francisco J. , Rodriguez Miguel , Stephenson William R.
Published: January 2020

We apply the SPAC method to investigate site response at three sites in the Wainuiomata valley. At each site, square arrays with a fifth station at the centre were used to record 35 minutes of ambient noise. Distance between the stations on the square and the central one were 10, 20, 40, and 80 m. The data were analyzed through the computation of cross-correlation among stations. The resulting functions were inverted for the phase velocity dispersion curve of Rayleigh waves at each site. The results are reliable in the frequency band 1.1 to 3.7 Hz. The dispersion curves were inverted for the shear wave velocity profile at each site. We observe only marginal differences between sites FWP and BHP, where large amplification is given by very soft soil relative to a significantly stiffer bedrock. The third site, MCP, shows a velocity gradient with depth, without a pronounced contrast in the depth range investigated. We computed transfer functions for vertical incidence of shear waves on the inverted profiles, and compared the results with horizontal-to-vertical spectral ratios of microtremor records. The differences between the two shed some light on the complementary nature of both types of measurement and suggest that any single measurement may lead to erroneous interpretations.
The prediction of building performance during earthquakes
Authors: Jury R.D.
Published: January 2020

Procedures for the seismic design of new buildings to achieve a minimum acceptable performance are well established. However, it is concluded in this paper that the actual performance of structures will not be predicted with any certainty using the same procedures, given the uncertainties associated with the assumptions that must be made. Sole reliance on design procedures to predict performance is likely to lead to unnecessary conservatism and this must be taken into account when setting standards for design.

It is also concluded that there is currently insufficient data available in a suitable form to enable the correlation between analysis and actual performance to be assessed in any way other than by judgement.

The prediction of seismic performance remains very much an art.
The 2003, Mw 7.2 Fiordland earthquake, and its near-source aftershock strong motion data
Authors: McGinty P.
Published: January 2020

The 2003 Fiordland earthquake was not only the best ever recorded subduction interface earthquake to occur in New Zealand, it also provided the opportunity to collect near-source strong-motion data produced by its aftershocks covering a wide magnitude range. Near source strong-motion data had been lacking in the New Zealand data set, on which current attenuation models are based. Here the author presents some preliminary results relating recorded peak ground accelerations in the near-source field to current attenuation models. The near-source data from the 2003 Fiordland earthquake sequence has shown that the observed data has a greater magnitude-dependence than that predicted by the current attenuation models. This new data will help to improve current models and will lead to a better understanding of the attenuation process associated with New Zealand subduction interface earthquakes.
The decision support model for risk management
Authors: Smith Warwick
Published: January 2020

Risk management decisions often demand the allocation of scarce resources in mitigation of different hazards. A quantitative basis for decision-making can be provided by a detailed risk assessment, in which the current risk and those that obtain under proposed projects can be evaluated. The average annual loss, or expected value, is not a useful measure of extreme risk. The conditional expected value, calculated for a series of probability ranges, provides measures of the risk that can be assembled into a decision table so that informed decisions can be made. The conditional expected value can be calculated even when the losses are only available in terms of a cumulative probability function.
Ash fall prediction in New Zealand
Authors: Poirot T. , Cole J. , Elms D.G.
Published: January 2020

The North Island of New Zealand contains seven active volcanoes or volcanic centres, and ash fall from these centres could present health hazards and other problems. Part of the required contingency planning for ash fall is the assessment of the frequency and depth of ash fall at any point. The issue is particularly important for urban areas likely to be affected. This paper develops a theory for ash fall frequency assessment based on estimated eruption frequencies and magnitudes and on meteorological data. The theory is used to obtain the ash fall frequency/depth relationship for the Napier /Hastings area in the Hawkes Bay region. The results show that the annual frequency of significant ash fall in the towns is high enough to justify some degree of emergency preparedness, with a fall of 1 mm having an annual exceedance probability of about 0.05, or in other words a return period of approximately 20 years.
Microzoning effects on damage in two major New Zealand earthquakes
Authors: Dowrick D. J. , Rhoades D. A. , Davenport P. N.
Published: January 2020

In a recent study the present authors examined the damage ratios for houses and household contents in the Inangahua, New Zealand, earthquake for intensities MM7-MM10, as affected by microzoning and structural types. The present study modestly revises this work, and extends it to include the localities of Nelson (MM6.4) and Murchison (MM8.1). Four ground classes and two foundation types, i.e. unbraced piles and concrete perimeter wall foundations were considered, and also number of storeys and wall cladding. Some complexities and difficulties of reliable microzoning are revealed and discussed.
Experimental response of framed masonry structures designed with new reinforcing details
Authors: Crisafulli Francisco J. , Carr Athol J. , Park Robert
Published: January 2020

This paper describes an experimental programme in which two one-storey single-bay specimens were tested under cyclic lateral loading. The first specimen was designed according to the normal practice for framed masonry structures, whereas new reinforcing details were provided in the second specimen, with the objective of enhancing the structural response. Special precautions were taken for the application of the lateral forces, considering that experimental and analytical results indicated that the loading system could markedly affect the structural response. Consequently, an adequate procedure should be adopted for laboratory tests in order to obtain realistic data. The most important conclusion of the experimental programme was that the response of reinforced concrete frames with masonry infills can be significantly improved by a rational design aimed at reducing the distortion of the masonry panels while the plastic deformations are concentrated in selected regions of the structure.
Base isolation of an existing 10-storey building to enhance earthquake resistance
Authors: Clark W.D. , Mason J.E.
Published: January 2020

The Rankine Brown Building at Victoria University of Wellington, New Zealand houses the University Library and is pivotal to the operation of the University. Built in the early 1960s, the building was of innovative form and construction for its time, with long span precast concrete waffle slabs over 10 floors supported on 16 main columns. Three years ago a review of the building structure suggested that increased protection of the building would be required to meet the University's expectation for operational continuity after a moderate or major earthquake event in the Wellington area. This paper outlines:

Probable areas of structural yielding in a major earthquake event.

Structural analysis for base isolation using earthquake time history records.

Details of base isolation bearings.

Installation of the base isolation bearings.

Other structural details that allow movement of the superstructure to take place due to base isolation.
Retrofit of seismically isolated structures for near-field ground motion using additional viscous damping
Authors: Carden Lyle P. , Davidson Barry J. , Larkin Tam J. , Buckle Ian G.
Published: January 2020

Recent earthquakes have shown that a large magnitude, long period pulse is often prevalent in ground motion records at sites within a few kilometres of the active fault during an earthquake. Near-field earthquake ground motion containing forward directivity effects can result in a larger response in flexible structures, such as seismically isolated structures, compared to that predicted for conventional ground shaking. Hence, a study was performed on a number of generic seismically isolated structures designed to the 1997 Uniform Building Code, as well as a case study on the William Clayton building in Wellington, to determine the impact of near-field ground motion. In optimising the performance of the buildings for both near-field and original "design level" earthquakes, it is concluded that linear viscous dampers added to the existing isolation systems are effective in controlling the response during large magnitude near-field earthquakes with minimal impact on the design response. Additional viscous damping is more effective than hysteretic damping in limiting isolator displacements while also preventing an increase in base shear and floor accelerations for far-field "design level" earthquakes.
Risk of casualties in New Zealand earthquakes
Authors: Dowrick David J. , Rhoades David A.
Published: January 2020

This paper reports on a study of all earthquakes that have caused (or could have caused) casualties in New Zealand in the period 1840 - 2003 inclusive. The intensity which has been the effective threshold for injuries is Modified Mercalli intensity VII (MM7). In the period of interest at least 73 earthquakes of magnitude Mw ≥ 5 have caused MM7 or greater in populated areas, and of these events 16 have caused direct casualties, 297 deaths and 640 hospitalized injured. The causes of the casualties are tabulated and discussed, and the potential to reduce casualties in the future is assessed, in particular in a large earthquake on the Wellington fault. Death rates have been determined empirically as functions of four types of structure and MM intensity.
Seismic design and behaviour of external reinforced concrete beam-column joints incorporating 500E grade steel reinforcing
Authors: Megget Leslie M.
Published: January 2020

Four external reinforced concrete beam-column sub-assemblages were tested under pseudo seismic cyclic loading. The approximately 2/3 scale units incorporated the new Grade 500E reinforcing steel as the beam bars. Two different forms of beam bar anchorage were tested, the normal 90-degree "standard hook" and the continuous U-bar detail. In all units the farthest point of the beam bar anchorage was positioned at the minimum limit prescribed in the NZ Concrete Standard (NZS3101), namely ¾ of the column depth from the inner column face. All 4 units formed plastic hinges in the beam and joint degradation was minor. Failure occurred at drift ratios between 4 and 6% (approximate ductility factors of between 4 and 6) predominantly due to buckling of the beam bars in the plastic hinge zone. The stiffness of these units was significantly less than similar units reinforced with 300E Grade reinforcing or the recently replaced 430 MPa reinforcement. The decreased stiffness will cause higher lateral drifts during large earthquakes, than those anticipated in current Standards.
Temporal variations of the earthquake data in the catalogue of seismicity of New Zealand
Authors: Zuniga F. R. , Reyners M. , Villamor P.
Published: January 2020

The authors have analyzed the main temporal characteristics of the earthquake data in the catalogue of seismicity of New Zealand with the objective of providing a general overview of its content and limitations. To this end we have employed different statistical tools which allow for the objective estimate of times of changes in the seismicity rates as well as providing the main reasons for those changes. We have found that the seismicity record of the largest events (M > 4.0) is bracketed by significant changes which occurred during 1940, 1965-1968, and 1987 with other less significant changes taking place during 1960, 1983 and 1992. By comparing the rates obtained for intervals bounded by the aforementioned dates we were able to determine that a linear correction to the magnitudes in the period 1968 to 1987 for the whole depth range of events may be useful in order to match the frequency-magnitude distribution which is obtained using the current data in the interval 1987 - 2004. A different pattern emerged when separating shallow from intermediate and deep events and we found that most of the temporal variations observed affected mainly the deep events (Z > 40 km), and that the reported rate of shallow seismicity for M > 4.0 has been remarkably homogeneous since 1940. This observation is supported not only by the constancy of seismicity rates but by the similarity of frequency-magnitude distributions during the time intervals analyzed. A systematic evaluation of minimum magnitude of completeness for shallow seismicity yielded values of Mc = 4.4 for the interval 1940 to 1968, Mc = 3.9 for the interval 1968 to 1987 and Mc = 2.6 for the current stage from 1987 to 2004. A simple magnitude shift of 0.2 units applied to data in the interval 1968 to 1987 for intermediate and deep events was found to provide a good match to the observed rate for events from 1987 to 2004. The evaluation of Mc for events in the 40 ≤ z ≤ 600 km range yielded values of 5.5 for data in the interval 1940 to 1968, 4.0 for 1968 to 1987, and 3.6 for the current operative practice starting in I 987. A detailed investigation of the variation of the magnitude of completeness with time was carried out resulting in different trends which seem to correspond to the time when major changes were carried out in the network, in particular with the installation and removal of local microcarthquake networks.
Survey of impacts on the Andaman coast, southern Thailand following the great Sumatra-Andaman earthquake and tsunami of December 26, 2004
Authors: Bell Robert , Cowan Hugh , Dalziell Erica , Evans Noel , O'Leary Mike , Rush Bernie , Yule Lawrence
Published: January 2020

This report on the Sumatra-Andaman great earthquake and tsunami of December 26, 2004 describes the event and its impacts in southern Thailand. It includes the observations of the New Zealand Society for Earthquake Engineering Reconnaissance Team gathered one month after the event. The report covers the effects of the tsunami on the natural and built environment, and the recovery process in relation to social and economic issues. Lessons applicable to the understanding and potential mitigation of tsunami risk in New Zealand are presented and discussed.
GIS-based emergency and evacuation planning for volcanic hazards in New Zealand
Authors: Cole J. W. , Sabel C. E. , Blumenthal E. , Finnis K. , Dantas A. , Barnard S. , Johnston D.M.
Published: January 2020

Geographic Information Systems (GIS) provide a range of techniques which allow ready access to data, and the opportunity to overlay graphical location-based information for ease of interpretation. They can be used to solve complex planning and management problems. All phases of emergency management (reduction, readiness, response and recovery) can benefit from GIS, including applications related to transportation systems, a critical element in managing effective lifelines in an emergency. This is particularly true immediately before and during a volcanic eruption.

The potential for volcanic activity in New Zealand is high, with 10 volcanoes or volcanic centres (Auckland, Bay of Islands, Haroharo, Mayor Island, Ruapehu, Taranaki, Tarawera, Taupo, Tongariro (including Ngauruhoe) and White Island) recognised as active or potentially active. In addition there are many active and potentially active volcanoes along the Kermadec Island chain. There is a great deal of background information on all of these volcanoes, and GIS is currently being used for some aspects of monitoring (e.g. ERS and Envisat radar interferometry for observing deformation prior to eruptions). If an eruption is considered imminent, evacuation may be necessary, and hence transportation systems must be evaluated. Scenarios have been developed for many centres (e.g. Taranaki/Egmont and Bay of Plenty volcanoes), but so far the use of GIS in planning for evacuation is limited.

This paper looks at the use of GIS, indicates how it is being used in emergency management, and suggests how it can be used in evacuation planning.