A photograph of a sign advertising the SCIRT website on the banks of the Avon River.
This report presents an overview of the soil profile characteristics at a number of strong motion station (SMS) sites in Christchurch and its surrounds. An extensive database of ground motion records has been captured by the SMS network in the Canterbury region during the Canterbury earthquake sequence. However in order to comprehensively understand the ground motions recorded at these sites and to be able to relate these motions to other locations, a detailed understanding of the shallow geotechnical profile at each SMS is required. The original NZS1170.5 (SNZ 2004) site subsoil classifications for each SMS site is based on regional geological information and well logs located at varying distances from the site. Given the variability of Christchurch soils, more detailed investigations are required in close vicinity to each SMS to better understand stratigraphy and soil properties, which are important in seismic site response. In this regard, CPT, SPT and borehole data, shear wave velocity (Vs) profiles, and horizontal to vertical spectral ratio measurements (H/V) in close vicinity to the SMS were used to develop representative soil profiles at each site. NZS1170.5 (SNZ 2004) site subsoil classifications were updated using Vs and SPT N60 criteria. Site class E boundaries were treated as a sliding scale rather than as a discrete boundary to account for locations with similar site effects potential, an approach which was shown to result in a better delineation between the site classes. SPT N60 values often indicate a stiffer site class than the Vs data for softer soil sites, highlighting the disparity between the two site investigation techniques. Both SPT N60 and Vs based site classes did not always agree with the original site classifications. This emphasises the importance of having detailed site‐specific information at SMS locations in order to properly classify them. Furthermore, additional studies are required to harmonize site classification based on SPT N60 and Vs. Liquefaction triggering assessments were carried out for the Darfield and Christchurch earthquakes, and compared against observed liquefaction surface manifestations and ground motions characteristics at each SMS. In general, the characteristics of the recorded ground motions at each site correlate well with the triggering analyses. However, at sites that likely liquefied at depth (as indicated by triggering analyses and/or inferred from the characteristics of the recorded surface acceleration time series), the presence of a non‐liquefiable crust layer at many of the SMS locations prevented the manifestation of any surface effects.
A manual which informs SCIRT AutoCAD users of all tools, utilities, keyboard shortcuts, and tips available within the SCIRT CAD System.
A design guideline which provides guidance to designers on how to carry out a whole of life evaluation of rebuild options.
A manual which provides SCIRT AutoCAD users with general guidance about how to use AutoCAD.
A designer's guideline which explains the role of Technical Leads at SCIRT.
A report which details the findings of a performance audit carried out by the Office of the Auditor-General to assess the effectiveness and efficiency of arrangements to repair Christchurch's horizontal infrastructure.
A document which details the structure, roles and terms of reference for the Client Governance Group (CGG).
A plan which details how in 2013 SCIRT planned to engage its workforce in training.
A guideline which defined the process and ownership of templates used by the design team and the management of the design team electronic library.
A document which contains a set of procedures for the "best practice" mark out and recording of subsurface utilities.
A copy of the award application for the New Zealand Engineering Excellence Awards 2013.
This document describes the tool developed for capturing the abandoned and removed assets using the SCIRT GIS viewer.
An example of a tool SCIRT has used to communicate its projects to the business community.
A guideline created for SCIRT Delivery Teams which outlines the requirements for working around heritage items.
A plan which describes the framework, principles and process for determining project prioritisation and the sequence in which those projects are carried out. The first version of this plan was produced on 23 September 2011.
A design guideline which provides information about how to use the SCIRT Asset Assessment Spreadsheet.
A poster which outlines the dewatering process.
A magazine article which outlines the observations of engineers working on SCIRT retaining wall and ground improvement projects.
An example of the five year rebuild schedule map created as part of the prioritisation process detailing where and when construction would start. The data behind this map was updated every quarter.
A document which details the agreement in September 2013 between the Government and the Christchurch City Council over governance of the horizontal infrastructure rebuild.
A guideline to inform designers of the pipe profilometer operation, including requesting profile surveys, standards and assessments of the survey results.
A design guideline which provides guidance to project definition and design teams on how to use Pipe Damage Assessment Tool (PDAT) outputs in their scoping and concept design work.
The Earthquake Recovery Minister says this is a final warning for the Christchurch City Council.
The city of Christchurch and its surrounds experienced widespread damage due to soil liquefaction induced by seismic shaking during the Canterbury earthquake sequence that began in September 2010 with the Mw7.1 Darfield earthquake. Prior to the start of this sequence, the city had a large network of strong motion stations (SMSs) installed, which were able to record a vast database of strong ground motions. This paper uses this database of strong ground motion recordings, observations of liquefaction manifestation at the ground surface, and data from a recently completed extensive geotechnical site investigation program at each SMS to assess a range of liquefaction evaluation procedures at the four SMSs in the Christchurch Central Business District (CBD). In general, the characteristics of the accelerograms recorded at each SMS correlated well with the liquefaction evaluation procedures, with low liquefaction factors of safety predicted at sites with clear liquefaction identifiers in the ground motions. However, at sites that likely liquefied at depth (as indicated by evaluation procedures and/or inferred from the characteristics of the recorded surface accelerograms), the presence of a non-liquefiable crust layer at many of the SMS locations prevented the manifestation of any surface effects. Because of this, there was not a good correlation between surface manifestation and two surface manifestation indices, the Liquefaction Potential Index (LPI) and the Liquefaction Severity Number (LSN).
This paper provides a summary of the ground motions observed in the recent Canterbury, New Zealand earthquake sequence. The sequence occurred in a region of relatively moderate seismicity, 130km to the east of the Alpine Fault, the major plate-boundary in the region. From an engineering perspective, the sequence has been primarily comprised of the initial 04/09/2010 Darfield earthquake (Mw7.1) followed by the 22/02/2011 Christchurch earthquake (Mw6.3), and two aftershocks on 13/06/ 2011 (Mw5.3 and 6.0, respectively). The dense spacing of strong motions in the region, and their close proximity to the respective causative faults, has resulted in strong ground motions far exceeding the previous catalogue of strong motion observed in New Zealand. The observed ground motions have exhibited clear evidence of: (i) near-source directivity; (ii) sedimentary basin focusing, amplification and basin effect refraction; (iii) non-linear site response; (iv) cyclic mobility postliquefaction; and (v) extreme vertical ground motions exceeding 2g, among others.
A video of the removal of the earthquake-damaged Medway Street bridge from the banks of the Avon River. The video shows members of the Stronger Christchurch Infrastructure Rebuild Team removing the bridge and preparing it for transport to the Ferrymead Heritage Park. It will remain at the park until a permanent home can be found for it as an earthquake memorial.
A small house is shown on an enormous foundation block labelled 'Rate$'. The cartoonist's comment is 'Like for like for the house...Total dislike for the foundation!' In Christchurch there were prospects of large rises in householders' rate to help finance the Christchurch Rebuild project. In view of the damage to housing, rate increases may be badly disproportionate. Quantity: 1 digital cartoon(s).
Vehicles drive through a flooded road in New Brighton. A sign advertising the stronger Christchurch website reads, 'Rebuilding for our future'.
The Christchurch City Council has received a strong warning from the Earthquake Recovery Minister to speed up its processing of building consents or lose its power to authorise consents.