21 results for Ingham, Jason, Conference item, 2010

  • Implications of the 2010 Darfield (Christchurch, NZ) earthquake for Australia ??? are we ready?

    Griffith, MC; Ingham, Jason; Moon, L (2010)

    Conference item
    The University of Auckland Library

    The 2010 Darfield earthquake is the largest earthquake on record to have occurred within 40 km of a major city and not cause any fatalities. In this paper the authors have reflected on their experiences in Christchurch following the earthquake with a view to what worked, what didn???t, and what lessons can be learned from this for the benefit of Australian earthquake preparedness. Owing to the fact that most of the observed building damage occurred in Unreinforced Masonry (URM) construction, this paper focuses in particular on the authors??? experience conducting rapid building damage assessment during the first 72 hours following the earthquake and more detailed examination of the performance of unreinforced masonry buildings with and without seismic retrofit interventions.

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  • Seismic strengthening of an unreinforced masonry building using ECC shotcrete

    Lin, Yi-Wei; Lawley, Derek; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    An Engineered Cementitious Composite (ECC) with a tensile strain-hardening capacity of 2% was shotcreted to an unreinforced masonry (URM) building as a seismic retrofit intervention following testing that was conducted to assess the feasibility of using ECC as the retrofitting material for seismic strengthening of URM buildings. In-plane testing of 1.2 metre ?? 1.2 metre masonry wallettes retrofitted with ECC showed that ECC reinforcement provided a 0.15 MPa increase in shear strength for every 10 mm of ECC. Two 4.1 metre high ?? 1.2 metre long walls with 30 mm of ECC on a single side of each wall were subjected to out-of-plane loading to simulate face-load earthquake response. The results showed an increase in maximum load of 1.6 times the strength of the as-built wall when ECC reinforcement was applied on the compression surface and an increase of 13.2 times when ECC reinforcement was applied on the tension surface. It was concluded that ECC is a suitable material for seismic retrofitting of URM buildings and an implementation case study of a two-storey URM building shotcreted with ECC is examined.

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  • Strength and stiffness of unreinforced masonry: comparison between laboratory and field studies

    Lumantarna, Ronald; Dizhur, Dmytro; Derakhshan, Hossein; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    Unreinforced masonry (URM) was the most popular form of construction in New Zealand during the early 20th century, and therefore URM buildings form a large proportion of the country???s heritage building stock. To assist in the preservation of these heritage buildings, the New Zealand Society for Earthquake Engineering (NZSEE) published a guideline for detailed seismic assessment of URM buildings, which provided the recommended masonry material properties to be used for preliminary assessment. However, these recommended properties were based on limited experimental testing. Structural seismic designers have communicated the importance of accurate URM material property data in order to improve the accuracy of their seismic assessments, computer modelling and retrofit designs, which will result in a reduced cost to seismically protect these heritage buildings. The work reported here focuses on the compressive strength and the stiffness of brick/mortar composites. Field samples were extracted from actual buildings to investigate the constituent material properties of New Zealand???s URM buildings and to confirm the relevance of findings derived from manufactured test samples. A predictive equation relating the brick, mortar and brick/mortar composite compressive strengths was developed and its suitability for New Zealand URM was assessed. The relationship between masonry compressive strength and the Modulus of Elasticity was also investigated and a provisional equation was developed. These predictive equations are intended as tools for structural seismic designers to predict masonry design material properties based upon the known brick and mortar properties.

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  • In-situ airbag testing of unreinforced masonry walls

    Derakhshan, Hossein; Lumantarna, R; Dizhur, D; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    A field testing programme was developed to investigate the out-of-plane behaviour of as-built unreinforced masonry (URM) walls of four buildings. The buildings were between approximately 80 to 130 years old, and had different masonry materials and construction forms. In total, 10 tests were performed on seven URM walls, with the out-of-plane force being uniformly applied to the wall surface. Several tests were repeated with original and modified support condition, and in particular, the effects of a concrete ring beam used at the floor levels of a URM building and the effects of wall anchorage to the building diaphragms by means of grouted steel rods were investigated. A bilinear model previously obtained through laboratory testing was proven to be effective for prediction of the cracked wall behaviour. Out-of-plane wall resistance was compared to the appropriate seismic demand of each site, and the results of the comparison were used to evaluate the NZSEE 2006 out-of- plane wall seismic evaluation method. Two of the tests were performed on two-way spanning walls, and the results showed that the two-way action significantly increased the wall resistance.

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  • Waste paint as a polymeric admixture substitute in concrete

    Almesfer, Nasser; Norton, G; Cook, D; McSaveney, L; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    PaintWise is a nationwide paint recovery program which is based upon the recognition that waste paint is a valuable resource that is currently being disposed of in landfills at a significant economic and environmental cost. In order to utilize the beneficial properties of this waste paint as an active ingredient to produce concrete, a PaintCrete Partnership involving 3R Group Ltd, Fletcher Concrete and Infrastructure Ltd, and Resene Paints was formed. 3R Group is responsible for managing and implementing the PaintWise program, and in 2009 the 3R Group diverted away from landfill and processed over 160,000 litres of waste paint. Waste paint exhibits many desirable properties that are similar to particularly expensive polymeric admixtures, which have been commonly used in the modification of cementitious applications for well over 70 years. These properties include improved rheology, strength, toughness and durability. These improvements are due to the polymer resins found in paint exhibiting similar advantages to polymers found in conventional polymeric admixtures. An investigation was performed to identify the suitability of waste paint as a polymeric admixture substitute to improve the fresh and hardened properties of concrete mixes. A considerable amount of commercial emphasis is placed on the research methodology, with a range of different ongoing commercial applications monitored via testing of both fresh and hardened concrete, while analyzing and modifying the concrete mix designs and production procedure as required, achieving desired performance characteristics. Lab-based trials were also undertaken in order to identify mixes with the potential to be trialed at commercial levels. Previous PaintCrete Partnership research into block-fill grout was not commercialized as insufficient fullscale trials were conducted, whereas the commercial emphasis of this investigation will be of assistance in producing the end result which is fully commercialized PaintCrete; a superior concrete solution which provides enhanced job-site productivity, improved strength and durability, and which is also good for our environment.

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  • Structural testing of unreinforced masonry assemblages retrofitted using twisted steel inserts

    Ismail, Najif; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    The seismic behaviour of unreinforced masonry (URM) assemblages retrofitted using twisted steel inserts was investigated. A total of 21 URM assemblages were tested, which involved 7 diagonal shear strength tests, 9 compression strength tests and 5 sliding shear tests. Typical old New Zealand URM was replicated by laying vintage solid clay bricks with ASTM type O mortar in a common bond pattern. The retrofit materials used were austenitic stainless steel twisted reinforcement bars with a tensile yield strength of 1100 MPa (referred to as bars herein) and a high bond strength thixotropic injectable grout (referred to as grout herein). The bars were inserted in surface cut grooves, 10 mm wide and 30 mm deep in size, and the grooves were filled with grout. Test specimens were retrofitted with varying reinforcement ratios and were tested using the ASTM standardized test procedure to determine the values of shear strength, shear modulus, and absorbed energy. Test results from the retrofitted specimens were compared to their counterpart from non-retrofitted specimens. It was inferred from the test results that steel inserts increased the shear strength and ductility of URM sub-assemblages. Increase in shear strength of retrofitted specimens ranged from 196% to 246% and the value of absorbed energy was increased by a factor of 3 to 12. A preliminary empirical equation for the shear strength evaluation of retrofitted URM walls was developed using experimental results. A statistical analysis was performed to check the correctness of the developed equation, and a mean standard deviation of 9% was observed.

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  • Seismic retrofitting of an unreinforced masonry building using ECC shotcrete

    Lin, YW; Lawley, D; Wotherspoon, Liam; Ingham, Jason (2010-10-07)

    Conference item
    The University of Auckland Library

    An Engineered Cementitious Composite (ECC) with a tensile strain-hardening capacity of 2% was shotcreted to unreinforced masonry (URM) to assess the feasibility of using ECC as the retrofitting material for seismic strengthening of URM buildings. In-plane testing of 1.2 m ?? 1.2 m masonry wallettes retrofitted with ECC showed that ECC reinforcement provided a 0.15 MPa increase in shear strength for every 10 mm of ECC. Two 4.1 m high ?? 1.2 m long walls with 30 mm of ECC on a single side of each wall were subjected to out-of-plane loading to simulate face-load earthquake response. Results showed an increase in maximum strength of 1.6 times the as-built wall when ECC reinforcement was applied on the compression surface and an increase of 13.2 times when ECC reinforcement was applied on the tension surface. From the results of this laboratory study it was concluded that ECC is a suitable material for seismic retrofitting of URM buildings, and based upon these experimental findings, ECC shotcrete was subsequently used as a seismic retrofit solution for a two-storey URM building case study, which is presented.

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  • The influence of flanges on the in-plane performance of URM walls in New Zealand buildings

    Russell, Alistair; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    The influence of flanges (return walls) on the in-plane lateral behaviour of unreinforced masonry (URM) walls is reported. Experimentation was conducted on clay brick masonry walls designed to replicate typical New Zealand construction in the early 20th Century and with flanges of different lengths and at different locations. Testing of URM walls showed that the presence of flanges has a significant effect on the in-plane response of the wall. The results of experimentation were compared with analytical results determined from previous research, with a high level of correlation. Consequently, it was concluded that the existing analytical model was suitable for determining the response of walls with flanges responding in-plane. Drift limits are also proposed, depending on the in-plane wall failure mode.

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  • Performance based out-of-plane posttensioning seismic retrofit design of unreinforced masonry walls

    Ismail, Najif; Ingham, Jason; Laursen, Peter (2010)

    Conference item
    The University of Auckland Library

    A performance based design procedure was developed based on the out-of-plane flexural testing of seismically retrofitted unreinforced masonry (URM) walls using posttensioning. A macro level single degree of freedom (SDOF) dynamic model for the retrofit design of URM walls was developed. The test walls were dynamically tested by exciting the walls with a hammer and the developed model was updated to match the actual dynamic response of the tested walls. The developed SDOF model was used to find the pushover capacity curve for the posttensioned walls. The New Zealand Loading Standard's (NZS 1170) defined elastic site spectrum was used to develop the demand spectra. Consequently, a simplified demand-capacity phase diagram was developed to study the seismic behaviour of posttensioned walls and was used to analyse the tested posttensioned URM wall. Using the graphically aided analysis, seismic performance of the wall was investigated and it was inferred that the simplified analysis procedure can be used for performance based posttensioning seismic retrofit design of New Zealand URM buildings.

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  • In-situ out-of-plane testing of unreinforced masonry wall segment in Wintec Block F building

    Dizhur, Dmytro; Derakhshan, Hossein; Lumantarna, Ronald; Ingham, Jason; Griffith, Michael (2010)

    Conference item
    The University of Auckland Library

    Most research considering seismic assessment of URM walls has been conducted using laboratory-based studies with well defined but artificial conditions. Thus, in-situ testing is required to provide data with which to validate the accuracy of laboratory-based studies of URM walls. Seismic strengthening of the Wintec Block F building in Hamilton allowed an opportunity for a team of researchers from the University of Auckland to conduct in-situ testing of a wall segment in the building. This allowed comparison with companion experiments that had previously been undertaken in a laboratory setting. This field testing involved the extraction of clay brick and mortar samples, flexural bond tests, and out-of-plane testing of a wall both in the as-built condition and after the installation of a near-surface mounted (NSM) carbon fibre reinforced polymer (CFRP) retrofit solution. Testing confirmed that the boundary conditions in real buildings can significantly affect experimental response, and also confirmed that the nearsurface mounted FRP solution is an excellent low-invasive option for seismic strengthening of unreinforced masonry buildings. Details of the history of the building and the methods used to undertake the field testing are reported, and experimental results are presented.

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  • Effects of unreinforced masonry wall slenderness ratio on out-of-plane post-cracking dynamic stability

    Derakhshan, Hossein; Ingham, Jason; Griffith, Michael (2010)

    Conference item
    The University of Auckland Library

    A large number of time-history analyses were performed on several unreinforced masonry (URM) walls that had different slenderness ratios, and the viability of adopting wall slenderness ratio as a criterion for seismic assessment was investigated. Several combinations of three wall properties were assumed to cover most walls found in New Zealand URM buildings, and 30 representative time-history records were used to perform analyses. Walls were either two-leaf thick with no overburden load applied or three-leaf thick having an overburden load applied equal to the weight of a typical second-storey two-leaf URM wall. Wall behavioural data was obtained based on a previous laboratory based study, and each wall was subjected to ground motion scenarios with increasing peak ground acceleration (PGA). The ground motion record PGA that caused the wall to undergo a displacement limit equal to 60% of wall instability displacement was identified, and the sensitivity of the obtained PGA to wall slenderness ratio was studied for all the used records. It was shown that increasing wall slenderness ratio resulted in the wall being more vulnerable.

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  • Field testing of URM walls seismically retrofitted using twisted steel inserts

    Ismail, Najif; Oyarzo Vera, C; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    This article presents the in-situ out-of-plane flexural testing of two (02) full scale unreinforced masonry (URM) walls seismically retrofitted using twisted steel inserts. The URM walls were tested on site at a historic villa that was built in 1880 and has a prime heritage value. The test walls were seismically retrofitted by inserting twisted stainless steel bars in cut surface grooves. The structural performance of these seismically retrofitted URM walls was investigated and was compared to their counter part from the non-retrofitted test walls. The elevation in out-of-plane flexural strength of the retrofitted URM walls ranged from 140% to 570%. The results for the retrofitted walls were plotted graphically as demand capacity phase diagram in spectral acceleration and spectral displacement (ADRS) format to depict the damage level for maximum credible earthquake.

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  • In-situ testing on a residential unreinforced masonry building located in New Zealand

    Dizhur, Dmytro; Lumantarna, Ronald; Derakhshan, Hossein; Griffith, Michael; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    Most research considering seismic assessment of URM walls has been conducted using laboratory-based studies with well defined but artificial boundary conditions. Thus, in-situ testing is required to provide data with which to validate the accuracy of laboratory-based studies of URM walls. Alterations, major refurbishment and structural seismic strengthening of Avon House, located in Wellington, New Zealand, involved demolition and removal of three large wall sections, allowing an opportunity for a team of researchers from the University of Auckland to conduct in-situ testing on the building. This allowed comparison with companion experiments that had previously been undertaken in a laboratory setting and provided an accurate seismic assessment of the building. This field testing involved the extraction of clay brick and mortar samples, in-situ bed joint shear tests, flexural bond tests, in-situ diagonal tension (shear) tests, and out-of-plane testing of the walls both in the existing condition and after the installation of a near-surface mounted (NSM) carbon fibre reinforced polymer (CFRP) retrofit solution. Testing confirmed that the walls in Avon House did not meet current New Zealand seismic performance requirements, and also confirmed that the near-surface mounted FRP solution is an excellent low-invasive option for seismic strengthening of unreinforced masonry buildings. Details of the history of the building, and the methods used to undertake the field testing are reported, and experimental results are presented.

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  • Testing of an earthquake-damaged unreinforced masonry building

    Dizhur, Dmytro; Lumantarna, Ronald; Derakhshan, Hossein; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    In December 2007 a magnitude 6.8 earthquake had an epicentre located approximately 50 km from the city of Gisborne, New Zealand. This earthquake caused damage to a number of buildings in Gisborne, and in particular, to numerous unreinforced masonry buildings. One such building was damaged to the extent that significant post-earthquake repairs were necessary, and partial removal of two of the building???s gable ended walls was required. This reconstruction allowed an opportunity for a team of researchers from the University of Auckland to conduct field tests on the building, allowing comparison with companion experiments that had previously been undertaken in a laboratory setting. This field testing involved the extraction of clay brick and mortar samples, in-situ bed joint shear tests, diagonal shear tests on samples extracted from the gabled walls, an in-situ in-plane shear test and out-of-plane testing of the gable ended wall both in the as-built condition and after the installation of a near-surface mounted (NSM) carbon fibre reinforced polymer (CFRP) retrofit solution. Testing confirmed that the boundary conditions in real buildings can significantly affect experimental response, with vertical restraint resulting in large increases in out-of-plane load capacity, and also confirmed that the near-surface mounted FRP solution is an excellent low-invasive option for seismic strengthening of unreinforced masonry. Details of the history of the building, and the methods used to undertake the field testing are reported, and experimental results are presented.

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  • An international comparison of ground motion selection criteria for seismic design

    Hachem, MM; Mathias, NJ; Wang, YY; Fajfar, P; Tsai, KC; Ingham, Jason; Oyarzo Vera, C; Lee, S (2010)

    Conference item
    The University of Auckland Library

    The use of ground motion records in the seismic design of structures is becoming more widespread due to the increasing availability of ground motion record databases and improving computing power. When designing significant structures, such as tall and important buildings, irregular structures, or long-span bridges in areas of high seismicity, engineers are increasingly required to perform dynamic analysis in order to show that the structure will perform satisfactorily in code design basis and rare design seismic events. Depending on the building code and structure involved, the engineer might be required to perform one or a combination of many types of seismic analyses including response spectrum analysis, nonlinear pushover analysis, and linear or nonlinear response history analysis. Those types of analysis are typically performed using artificial and/or recorded ground motion records that are usually scaled and/or modified to match the code,s design spectrum for the design event of interest. Different codes specify different and sometimes ambiguous guidelines and requirements on how the selection and matching of the design records are to be performed. The actual process followed is often a function of the individual interpretation of the seismologist or engineer, and is influenced by local common practice and the interpretations of building departments and peer review committees. In this paper, a survey of current code requirements and common practices in several countries, including the United States, China, the European Union, New Zealand and Taiwan, is presented. The intent of the paper is to present and compare the current code requirements and practices in these regions, and investigate similarities and differences, and opportunities for harmonization.

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  • Assessing the Bolted Connection Strength of New Zealand Hardwood

    Abdul Karim, Abdul Razak; Quenneville, Pierre; M Sa'Don, N; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    From published literature, it was found that through-bolt connections were typically applied as a retrofit technique to most New Zealand unreinforced masonry (URM) buildings following the 1931 Hawke???s Bay earthquake. As connection failure by tearing out part of the diaphragm joist was observed in past earthquakes due to lateral earthquake loading, the strength of the bolted connection in existing indigenous New Zealand timber joists needs to be assessed. The main objectives of this study were to evaluate the strength and to identify the possible failure modes of bolted connections in New Zealand hardwood. Bolted connection tests loaded parallel-to-grain were performed using recycled native New Zealand Matai and Rimu hardwoods because the timber diaphragms in URM buildings are typically constructed using such wood species. From the experimental study, it was observed that the timber bolted connection can fail in either ductile or brittle modes. The test results obtained were compared with the European Yield Model (EYM), the New Zealand timber code (NZS 3603:1993), and a proposed set of equations (Quenneville 2009) in order to evaluate the applicability of those equations in predicting bolted connection strength for New Zealand hardwood. It was found that the EYM equations provide better predictions than the NZS 3603:1993 when compared to the actual capacity. However, the EYM predictions are only good in estimating the strength of timber bolted connections that fail under ductile mode. For the connections that fail exhibiting the brittle mode, the proposed row shear equation by Quenneville was found to give better strength estimation.

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  • Assessing the validity of rocking in URM perforated shear walls

    Knox, Charlotte; Ma, Tsun Ming Quincy; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    The validity of implementing a ???rocking wall retrofit??? for New Zealand???s earthquake prone unreinforced masonry buildings was assessed. The parameters governing rocking response are detailed, and the identification of rocking-sympathetic characteristics in representative New Zealand unreinforced masonry building typologies are highlighted. A series of experimental tests were conducted in order to identify variables that had potential to alter the rocking response of piers subjected to seismic loading. The influence of boundary conditions on the failure mechanism of unreinforced masonry piers is discussed in relation to the design of the full scale testing rig. Results from testing of two full scale unreinforced masonry sub-structures consisting of two piers coupled by a deep spandrel are reported. The tests access the influence of aspect ratio and vertical precompression levels on the forcedisplacement and pier-spandrel rotational behaviour. Crack patterns evidenced in a series of plaster formed scale models is compared to those developed during full scale pseudo-static cyclic tests on unreinforced masonry shear walls of the same geometry.

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  • Experimental Study of Unreinforced Masonry Pier Sub-Structures

    Knox, Charlotte; Russell, Alistair; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    Accurate assessment of the structural response of unreinforced masonry buildings when subjected to earthquake loading is essential for the design of efficient and effective seismic retrofit interventions. This study focused on determining the in-plane seismic performance of unreinforced masonry perforated shear walls in order to implement controlled rocking response as a hybrid retrofit solution. The experimental programme and the findings from a series of pseudo-static push-over tests performed on coupled unreinforced masonry pier sub-structures is presented. These sub-structures consisted of two piers with varying aspect ratio and absolute size and were subjected to different levels of vertical overburden. The walls were constructed in the common American bond formation using solid clay bricks and a 1:2:9 composition lime mortar, consistent with historical New Zealand unreinforced masonry buildings. The specimen geometries were chosen to not only replicate typical New Zealand unreinforced masonry perforated shear wall geometries but to also provide data on the three possible failure mechanisms ??? diagonal shear failure, sliding shear failure and rocking flexural response.When subjected to horizontal load the piers in both sub-structures exhibited a rocking response, with no diagonal shear cracking visible. The damage was concentrated in the spandrel section that spanned across the opening and this was attributed to both flexure and shear forces within the spandrel.

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  • Modelling the Flushing Mechanism of Thin Flexible Surfaced Pavements in New Zealand

    Kodippily, Sachi; Henning, Theunis; Ingham, Jason; CENEK, P (2010)

    Conference item
    The University of Auckland Library

    Flushing is a major cause of maintenance on chipsealed pavements in New Zealand. Accurate understanding of flushing can have a significant impact in terms of predicting future maintenance needs, expenditure, and performance of pavements. Currently available literature does not provide sufficient information to gain a mechanistic understanding of this defect. Therefore, developing a flushing forecasting model remains a priority for the road asset management sector in New Zealand. The reported research aimed to develop a mechanistic understanding of the processes involved with the flushing defect. The study primarily focused on identifying methods that can be used to investigate the particular mechanisms causing flushing on pavements based on network level data. Twenty five pavement sites on state highways of Napier/ Hawke???s Bay region of New Zealand were identified, with top surface lives ranging from three to nine years. Historical pavement data from these sites were analysed and the results combined with analysis of Long-Term Pavement Performance data to identify the main mechanisms causing flushing on chipsealed pavements. Surface depth and roughness were found to have the greatest influence on flushing, while surface texture measured by sand circles was found to be a satisfactory indicator of probable flushed chipseals. It is intended that these findings will contribute to the development of the flushing forecasting model for chipsealed pavements in New Zealand.

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  • Damage to concrete structures from the 2010 Darfield (Canterbury, NZ) earthquake

    Ingham, Jason; Wotherspoon, L; Hogan, Lucas; Ragued, B (2010)

    Conference item
    The University of Auckland Library

    The 2010 M7.1 Darfield earthquake was the largest natural disaster to occur in New Zealand since the 1931 Hawke???s Bay earthquake and caused extensive liquefaction and ground spreading, which led to damage to a large number of residential buildings. This damage was particularly significant because of the number of families that had to evacuate their homes, and because of the extensive cost of remediation to these homes. Underground concrete water and wastewater services were significantly damaged, and concerns were raised that water supplies were contaminated, such that bottled water was necessary. Extensive damage occurred to many unreinforced masonry buildings, but damage to concrete buildings was minor, and was attributed to poor seismic detailing. Damage to concrete bridges was primarily associated with spreading of bridge abutments and damage to bridge approaches, and only eight vehicle bridges were closed. Damage to the concrete wharfs at Lyttelton Port was also primarily attributable to ground spreading, and whilst remediation will be expensive, the port was able to remain fully operational. Overall, concrete structures performed very well in the earthquake.

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