The November 2016 MW 7.8 Kaikōura Earthquake initiated beneath the North Culverden basin on The Humps fault and propagated north-eastwards, rupturing at least 17 faults along a cumulative length of ~180 km. The geomorphic expression of The Humps Fault across the Emu Plains, along the NW margin of Culverden basin, comprises a series of near-parallel strands separated by up to 3 km across strike. The various strands strike east to east-northeast and have been projected to mainly dip steeply to the south in seismic data (~80°). In this area, the fault predominantly accommodates right-lateral slip, with uplift and subsidence confined to releasing and restraining bends and step-overs at a range of scales. The Kaikōura event ruptured pre-existing fault scarps along the Emu Plains, which had been partly identified prior to the earthquake. Geomorphology and faulting expression of The Humps Fault on The Emu Plains was mapped, along with faulting related structures which did not rupture in the 2016 earthquake. Fault ruptures strands are combined into sections and the kinematic deformation of sections analysed to provide a moment tensor fault plane solution. This fault plane solution is consistent with the regional principal horizontal shortening direction (PHS) of ~115°, similar to seismic focal mechanism solutions of some of the nearby aftershocks of the Kaikōura earthquake, and similar to the adjacent Hope Fault. To constrain the timing of paleoseismic events, a trench was excavated across the fault where it crossed a late Quaternary alluvial fan. Mapping of stratigraphy exposed in the trench walls, and dating of variably deformed strata, constrains the pre-historic earthquake event history at the trench site. The available data provides evidence for at least three paleo-earthquakes within the last 15.1 ka, with a possible fourth (penultimate) event. These events are estimated to have occurred at 7.7-10.3 ka, 10.3-14.8 ka, and one or more events that are older than ~15.1 ka. Some evidence suggests an additional penultimate event between 1850 C.E and 7.7 ka. Time-integrated slip-rates at three locations on the fault are measured using paleo-channels as piercing points. These sites give horizontal slip rates of 0.57 ± 0.1 mm/year, 0.49 ± 0.1 mm/year and one site constrains a minimum of between 0.1 - 0.4 mm/year. Two vertical slip-rates are calculated to be constrained to a maximum of 0.2 ± 0.02 mm/year at one site and between 0.02 and 0.1 mm/year at another site. Prior to this study, The Humps fault had only been partially documented in reconnaissance level mapping in the district, and no previous paleoseismic or slip rate data had been reported. This project has provided a detailed fault zone tectonic geomorphic map and established new slip-rate and paleoseismic data. The results highlight that The Humps fault plays an important role in regional seismicity and in accommodating plate boundary deformation across the North Canterbury region.
This thesis documents the development and demonstration of an assessment method for analysing earthquake-related damage to concrete waste water gravity pipes in Christchurch, New Zealand, following the 2010-2011 Canterbury Earthquake Sequence (CES). The method is intended to be internationally adaptable to assist territorial local authorities with improving lifelines infrastructure disaster impact assessment and improvements in resilience. This is achieved through the provision of high-resolution, localised damage data, which demonstrate earthquake impacts along the pipe length. The insights gained will assist decision making and the prioritisation of resources following earthquake events to quickly and efficiently restore network function and reduce community impacts. The method involved obtaining a selection of 55 reinforced concrete gravity waste water pipes with available Closed-Circuit Television (CCTV) inspection footage filmed before and after the CES. The pipes were assessed by reviewing the recordings, and damage was mapped to the nearest metre along the pipe length using Geographic Information Systems. An established, systematic coding process was used for reporting the nature and severity of the observed damage, and to differentiate between pre-existing and new damage resulting from the CES. The damage items were overlaid with geospatial data such as Light Detection and Ranging (LiDAR)-derived ground deformation data, Liquefaction Resistance Index data and seismic ground motion data (Peak Ground acceleration and Peak Ground Velocity) to identify potential relationships between these parameters and pipe performance. Initial assessment outcomes for the pipe selection revealed that main pipe joints and lateral connections were more vulnerable than the pipe body during a seismic event. Smaller diameter pipes may also be more vulnerable than larger pipes during a seismic event. Obvious differential ground movement resulted in increased local damage observations in many cases, however this was not obvious for all pipes. Pipes with older installation ages exhibited more overall damage prior to a seismic event, which is likely attributable to increased chemical and biological deterioration. However, no evidence was found relating pipe age to performance during a seismic event. No evidence was found linking levels of pre-CES damage in a pipe with subsequent seismic performance, and seismic performance with liquefaction resistance or magnitude of seismic ground motion. The results reported are of limited application due to the small demonstration sample size, but reveal the additional level of detail and insight possible using the method presented in this thesis over existing assessment methods, especially in relation to high resolution variations along the length of the pipe such as localised ground deformations evidenced by LiDAR. The results may be improved by studying a larger and more diverse sample pool, automating data collection and input processes in order to improve efficiency and consider additional input such as pipe dip and cumulative damage over a large distance. The method is dependent on comprehensive and accurate pre-event CCTV assessments and LIDAR data so that post-event data could be compared. It is proposed that local territorial authorities should prioritise acquiring this information as a first important step towards improving the seismic resilience of a gravity waste water pipe network.
This thesis documents the development and demonstration of an assessment method for analysing earthquake-related damage to concrete waste water gravity pipes in Christchurch, New Zealand, following the 2010-2011 Canterbury Earthquake Sequence (CES). The method is intended to be internationally adaptable to assist territorial local authorities with improving lifelines infrastructure disaster impact assessment and improvements in resilience. This is achieved through the provision of high-resolution, localised damage data, which demonstrate earthquake impacts along the pipe length. The insights gained will assist decision making and the prioritisation of resources following earthquake events to quickly and efficiently restore network function and reduce community impacts. The method involved obtaining a selection of 55 reinforced concrete gravity waste water pipes with available Closed-Circuit Television (CCTV) inspection footage filmed before and after the CES. The pipes were assessed by reviewing the recordings, and damage was mapped to the nearest metre along the pipe length using Geographic Information Systems. An established, systematic coding process was used for reporting the nature and severity of the observed damage, and to differentiate between pre-existing and new damage resulting from the CES. The damage items were overlaid with geospatial data such as Light Detection and Ranging (LiDAR)-derived ground deformation data, Liquefaction Resistance Index data and seismic ground motion data (Peak Ground acceleration and Peak Ground Velocity) to identify potential relationships between these parameters and pipe performance. Initial assessment outcomes for the pipe selection revealed that main pipe joints and lateral connections were more vulnerable than the pipe body during a seismic event. Smaller diameter pipes may also be more vulnerable than larger pipes during a seismic event. Obvious differential ground movement resulted in increased local damage observations in many cases, however this was not obvious for all pipes. Pipes with older installation ages exhibited more overall damage prior to a seismic event, which is likely attributable to increased chemical and biological deterioration. However, no evidence was found relating pipe age to performance during a seismic event. No evidence was found linking levels of pre-CES damage in a pipe with subsequent seismic performance, and seismic performance with liquefaction resistance or magnitude of seismic ground motion. The results reported are of limited application due to the small demonstration sample size, but reveal the additional level of detail and insight possible using the method presented in this thesis over existing assessment methods, especially in relation to high resolution variations along the length of the pipe such as localised ground deformations evidenced by LiDAR. The results may be improved by studying a larger and more diverse sample pool, automating data collection and input processes in order to improve efficiency and consider additional input such as pipe dip and cumulative damage over a large distance. The method is dependent on comprehensive and accurate pre-event CCTV assessments and LIDAR data so that post-event data could be compared. It is proposed that local territorial authorities should prioritise acquiring this information as a first important step towards improving the seismic resilience of a gravity waste water pipe network.
Christchurch Ōtautahi, New Zealand, is a city of myriad waterways and springs. Māori, the indigenous people of New Zealand, have water quality at the core of their cultural values. The city’s rivers include the Avon/Ōtākaro, central to the city centre’s aesthetic appeal since early settlement, and the Heathcote/Ōpāwaho. Both have been degraded with increasing urbanisation. The destructive earthquake sequence that occurred during 2010/11 presented an opportunity to rebuild significant areas of the city. Public consultation identified enthusiasm to rebuild a sustainable city. A sustainable water sensitive city is one where development is constructed with the water environment in mind. Water sensitive urban design applies at all scales and is a holistic concept. In Christchurch larger-scale multi-value stormwater management solutions were incorporated into rapidly developed greenfield sites on the city’s outskirts and in satellite towns, as they had been pre-earthquake. Individual properties on greenfield sites and within the city, however, continued to be constructed without water sensitive features such as rainwater tanks or living roofs. This research uses semi-structured interviews, policy analysis, and findings from local and international studies to investigate the benefits of building-scale WSUD and the barriers that have resulted in their absence. Although several inter-related barriers became apparent, cost, commonly cited as a barrier to sustainable development in general, was strongly represented. However, it is argued that the issue is one of mindset rather than cost. Solutions are proposed, based on international and national experience, that will demonstrate the benefits of adopting water sensitive urban design principles including at the building scale, and thereby build public and political support. The research is timely - there is still much development to occur, and increasing pressures from urban densification, population growth and climate change to mitigate.
The Stone Jug Fault (SJF) ruptured during the November 14th, 2016 (at 12:02 am), Mw 7.8 Kaikōura Earthquake which initiated ~40 km west-southwest of the study area, at a depth of approximately 15 km. Preliminary post-earthquake mapping indicated that the SJF connects the Conway-Charwell and Hundalee faults, which form continuous surface rupture, however, detailed study of the SJF had not been undertaken prior to this thesis due to its remote location and mountainous topography. The SJF is 19 km long, has an average strike of ~160° and generally carries approximately equal components of sinistral and reverse displacement. The primary fault trace is sigmoidal in shape with the northern and southern tips rotating in strike from NNW to NW, as the SJF approaches the Hope and Hundalee faults. It comprises several steps and bends and is associated with many (N=48) secondary faults, which are commonly near irregularities in the main fault geometry and in a distributed fault zone at the southern tip. The SJF is generally parallel to Torlesse basement bedding where it may utilise pre-existing zones of weakness. Horizontal, vertical and net displacements range up to 1.4 m, with displacement profiles along the primary trace showing two main maxima separated by a minima towards the middle and ends of the fault. Average net displacement along the primary trace is ~0.4m, with local changes in relative values of horizontal and vertical displacement at least partly controlled by fault strike. Two trenches excavated across the northern segment of the fault revealed displacement of mainly Holocene stratigraphy dated using radiocarbon (N=2) and OSL (N=4) samples. Five surface-rupturing paleoearthquakes displaying vertical displacements of <1 m occurred at: 11,000±1000, 7500±1000, 6500±1000, 3500±100 and 3 (2016 Kaikōura) years BP. These events produce an average slip rate since ~11 ka of 0.2-0.4 mm/yr and recurrence intervals of up to 5500 years with an average recurrence interval of 2750 yrs. Comparison of these results with unpublished trench data suggests that synchronous rupture of the Hundalee, Stone Jug, Conway-Charwell, and Humps faults at ~3500 yrs BP cannot be discounted and it is possible that multi-fault ruptures in north Canterbury are more common than previously thought.
The National Science Challenge ‘Building Better Homes, Towns and Cities’ is currently undertaking work that, in part, identifies and analyses the Waimakariri District Council’s (WMK/Council) organisational practices and process tools. The focus is on determining the processes that made the Residential Red Zone Recovery Plan, 2016 (RRZRP) collaboration process so effective and compares it to the processes used to inform the current Kaiapoi Town Centre Plan - 2028 and Beyond (KTC Plan). This research aims to explore ‘what travelled’ in terms of values, principles, methods, processes and personnel from the RRZRP to the KTC planning process. My research will add depth to this research by examining more closely the KTC Plan’s hearings process, reviewing submissions made, analysing background documents and by conducting five semi-structured interviews with a selection of people who made submissions on the KTC Plan.
The link between community involvement and best recovery outcomes has been acknowledged in literature as well as by humanitarian agencies (Lawther, 2009; Sullivan, 2003). My research has documented WMK’s post-quake community engagement strategy by focusing on their initial response to the earthquake of 2010 and the two-formal plan (RRZRP and KTC Plan) making procedures that succeeded this response.
My research has led me to conclude that WMK was committed to collaborating with their constituents right through the extended post-quake sequence. Iterative face to face or ‘think communications’ combined with the accessibility of all levels of Council staff – including senior management and elected members - gave interested community members the opportunity to discuss and deliberate the proposed plans with the people tasked with preparing them. WMK’s commitment to collaborate is illustrated by the methods they employed to inform their post-quake efforts and plans and by the logic behind the selected methods. Combined the Council’s logic and methods best describe the ‘Waimakariri Way’.
My research suggests that collaborative planning is iterative in nature. It is therefore difficult to establish a specific starting point where collaboration begins as the relationships needed for the collaborative process constantly (re)emerge out of pre-existing relationships. Collaboration seems to be based on an attitude, which means there is no starting ‘point’ as such, rather an amplification for a time of a basic attitude towards the public.
