Generalised parametric functions and spatial correlations for seismic velo…
Research papers, University of Canterbury Library
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This study uses 44 high quality liquefaction case histories taken from 22 locations affected by the 2010-2011 Canterbury earthquake sequence to evaluate four commonly used CPT-VS correlations (i.e., Robertson, 2009; Hegazy and Mayne, 2006; Andrus et al., 2007; McGann et al., 2015b). Co-located CPT soundings and VS profiles, developed from surface wave testing, were obtained at 22 locations and case histories were developed for the Mw 7.1, 4 September 2010 Darfield and Mw 6.2, 22 February 2011 Christchurch earthquakes. The CPT soundings are used to generate VS profiles using each of four CPT-VS correlations. These correlated VS profiles are used to estimate the factor of safety against liquefaction using the Kayen et al. (2013) VS-based simplified liquefaction evaluation procedure. An error index is used to quantify the predictive capabilities of these correlations in relation to the observations of liquefaction (or the lack thereof). Additionally, the error indices from the CPT-correlated VS profiles are compared to those obtained using: (1) the Kayen et al. (2013) procedure with surface wave-derived VS profiles, and (2) the Idriss and Boulanger (2008) CPT-based liquefaction evaluation procedure. Based on the error indices, the evaluation procedures based on direct measurements of either CPT or VS provided more accurate liquefaction triggering estimates than those obtained from any of the CPT-VS correlations. However, the performance of the CPT-VS correlations varied, with the Robertson (2009) and Hegazy and Mayne (2006) correlations performing relatively poorly for the Christchurch soils and the Andrus et al. (2007) and McGann et al. (2015b) correlations performing better. The McGann et al. (2015b) correlation had the lowest error indices of the CPT-VS correlations tested, however, none of the CPT-VS correlations provided accurate enough VS predictions to be used for the evaluation of liquefaction triggering using the VS-based liquefaction evaluation procedures.
The focus of the study presented herein is an assessment of the relative efficacy of recent Cone Penetration Test (CPT) and small strain shear wave velocity (Vs) based variants of the simplified procedure. Towards this end Receiver Operating Characteristic (ROC) analyses were performed on the CPT- and Vs-based procedures using the field case history databases from which the respective procedures were developed. The ROC analyses show that Factors of Safety (FS) against liquefaction computed using the most recent Vs-based simplified procedure is better able to separate the “liquefaction” from the “no liquefaction” case histories in the Vs liquefaction database than the CPT-based procedure is able to separate the “liquefaction” from the “no liquefaction” case histories in the CPT liquefaction database. However, this finding somewhat contradicts the assessed predictive capabilities of the CPT- and Vs-based procedures as quantified using select, high quality liquefaction case histories from the 20102011 Canterbury, New Zealand, Earthquake Sequence (CES), wherein the CPT-based procedure was found to yield more accurate predictions. The dichotomy of these findings may result from the fact that different liquefaction field case history databases were used in the respective ROC analyses for Vs and CPT, while the same case histories were used to evaluate both the CPT- and Vs-based procedures.
The M7.8 Kaikoura Earthquake in 2016 presented a number of challenges to science agencies and institutions throughout New Zealand. The earthquake was complex, with 21 faults rupturing throughout the North Canterbury and Marlborough landscape, generating a localised seven metre tsunami and triggering thousands of landslides. With many areas isolated as a result, it presented science teams with logistical challenges as well as the need to coordinate efforts across institutional and disciplinary boundaries. Many research disciplines, from engineering and geophysics to social science, were heavily involved in the response. Coordinating these disciplines and institutions required significant effort to assist New Zealand during its most complex earthquake yet recorded. This paper explores that effort and acknowledges the successes and lessons learned by the teams involved.
At 00:02 on 14th November 2016, a Mw 7.8 earthquake occurred in and offshore of the northeast of the South Island of New Zealand. Fault rupture, ground shaking, liquefaction, and co-seismic landslides caused severe damage to distributed infrastructure, and particularly transportation networks; large segments of the country’s main highway, State Highway 1 (SH1), and the Main North Line (MNL) railway line, were damaged between Picton and Christchurch. The damage caused direct local impacts, including isolation of communities, and wider regional impacts, including disruption of supply chains. Adaptive measures have ensured immediate continued regional transport of goods and people. Air and sea transport increased quickly, both for emergency response and to ensure routine transport of goods. Road diversions have also allowed critical connections to remain operable. This effective response to regional transport challenges allowed Civil Defence Emergency Management to quickly prioritise access to isolated settlements, all of which had road access 23 days after the earthquake. However, 100 days after the earthquake, critical segments of SH1 and the MNL remain closed and their ongoing repairs are a serious national strategic, as well as local, concern. This paper presents the impacts on South Island transport infrastructure, and subsequent management through the emergency response and early recovery phases, during the first 100 days following the initial earthquake, and highlights lessons for transportation system resilience.
At 00:02 on 14th November 2016, a Mw 7.8 earthquake occurred in and offshore of the northeast of the South Island of New Zealand. Fault rupture, ground shaking, liquefaction, and co-seismic landslides caused severe damage to distributed infrastructure, and particularly transportation networks; large segments of the country’s main highway, State Highway 1 (SH1), and the Main North Line (MNL) railway line, were damaged between Picton and Christchurch. The damage caused direct local impacts, including isolation of communities, and wider regional impacts, including disruption of supply chains. Adaptive measures have ensured immediate continued regional transport of goods and people. Air and sea transport increased quickly, both for emergency response and to ensure routine transport of goods. Road diversions have also allowed critical connections to remain operable. This effective response to regional transport challenges allowed Civil Defence Emergency Management to quickly prioritise access to isolated settlements, all of which had road access 23 days after the earthquake. However, 100 days after the earthquake, critical segments of SH1 and the MNL remain closed and their ongoing repairs are a serious national strategic, as well as local, concern. This paper presents the impacts on South Island transport infrastructure, and subsequent management through the emergency response and early recovery phases, during the first 100 days following the initial earthquake, and highlights lessons for transportation system resilience.
METIRIA TUREI to the Minister for the Environment: Ki Te Minita mō Te Taiao: Ka tukua e ngā paerewa e whakaarohia akehia nei mō te pai ake o te wai i roto i te pūhera Wai Mā, te kaha kē atu, te iti kē iho rānei o te uru atu o te tūkinotanga ki roto i ō tātou awa wai, e ngā mea whakakapi? Translation: Do the proposed standards for water quality in the Clean Water package allow more pollution or less to enter our waterways than the ones they will replace? BRETT HUDSON to the Minister of Finance: How much is the Government committing to spend on infrastructure over the next 4 years? ANDREW LITTLE to the Prime Minister: Given his predecessor told the Pike River families, “I’m here to give you absolute reassurance we’re committed to getting the boys out, and nothing’s going to change that”, when, if ever, will he be announcing the re-entry of the drift? STUART SMITH to the Minister of Transport: What announcements has he made recently regarding the Government’s commitment to reinstate key transport links following the Kaikōura earthquake? JACINDA ARDERN to the Minister for Children: When was she first notified that the Ministry for Vulnerable Children Oranga Tamariki, or its predecessor CYF, were placing children and younger persons in a hotel or motel for short-term care without a supervisor, and what was her first action, if any? MELISSA LEE to the Minister of Health: Can he confirm that 55,000 care and support workers will share in the $2 billion pay equity settlement announced on 18 April 2017? GRANT ROBERTSON to the Minister of Finance: Does he agree with the Dominion Post editorial that his Government has “singularly failed to answer the pressures of Auckland”; if not, why does he think they would write this? ANDREW BAYLY to the Minister for Building and Construction: How do the latest reports on the level of building activity in Auckland and nationwide for the month, quarter, and year compare with 2016? Rt Hon WINSTON PETERS to the Prime Minister: Does he stand by all his statements; if so, how? PHIL TWYFORD to the Minister of Transport: Why has the completion of the $2.4 billion Western Ring Route been delayed, and when can Aucklanders expect the new motorway to be open? EUGENIE SAGE to the Minister of Conservation: Is it Government policy to increase the logging of native forests on West Coast conservation land? Dr MEGAN WOODS to the Minister supporting Greater Christchurch Regeneration: Does she agree that the first homes in the East Frame will be completed 5 months ahead of schedule? Questions to Members CLARE CURRAN to the Chairperson of the Commerce Committee: Does she intend to call for further submissions on the petition of Dame Fiona Kidman before it is reported back to the House, in light of the recently released footage shot inside the drift of the Pike River mine?