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Images, UC QuakeStudies

A photograph looking south down Montreal Street from the Bealey Avenue. The road has been cordoned off with road cones and a member of the New Zealand Army in a high-visibility vest can be seen guarding it. In the background, a New Zealand Army vehicle can be seen with more soldiers. Some are on bikes to the right.

Images, UC QuakeStudies

A photograph of an earthquake-damaged house on Marine Parade in North Brighton. The front section of the house has collapsed, the rest buckled. The wall of the gable has also collapsed as well as part of the lower front wall. A red sticker in the window indicates that the building is unsafe to enter. A message has been spray painted on the front window, reading, "Roof tiles, $3 each". Police tape has been used to cordon off the house. Public notices can be seen on the fence, on the roof of the collapsed section and the section behind.

Images, eqnz.chch.2010

The earthquake re-pair work has started on the Knox Church on Bealey Avenue, August 14, 2013 Christchurch New Zealand. While building after building is torn down in Christchurch, plans are in place to ensure as much of a 131-year-old church is retained as possible. Knox Church on Bealey Avenue suffered major damage in the February 22 earthquak...

Images, UC QuakeStudies

Damage to River Road in Richmond. The road surface is badly cracked and slumped, and liquefaction silt covers part of the road. Two people in gumboots walk towards a barrier erected across the road using road cones and warning tape, and in the background the badly twisted Medway Street bridge can be seen. The photographer comments, "Longitudinal cracks indicate lateral movement as the land sagged towards the river. Near 373 River Rd, looking south-east towards Medway St. The Medway St bridge is visible in the background".

Images, UC QuakeStudies

A photograph of the earthquake damage to the Carlton Hotel on the corner of Papanui Road and Bealey Avenue. The wall of the top storey of the building has crumbled, and bricks have fallen onto the footpath. Wire fencing, road cones, and cordon tape have been placed around the building as a cordon. Scaffolding and steel bracing can be seen against the front of the building.

Images, UC QuakeStudies

Damage to buildings along Norwich Quay in Lyttelton. To the left is the Lyttelton Hotel with a crumbled top. Bricks have fallen on the awning and all along the footpath. To the right is a cafe that was damaged severely in the earthquake. The front wall of the top storey has crumbled onto the street, crushing a car. Wire fencing and road cones have been used to create a cordon around the buildings.

Images, UC QuakeStudies

Damage to buildings along Norwich Quay in Lyttelton. To the left is the Lyttelton Hotel with a crumbled top. Bricks have fallen on the awning and all along the footpath. To the right is a cafe that was damaged severely in the earthquake. The front wall of the top storey has crumbled onto the street, crushing a car. Wire fencing and road cones have been used to create a cordon around the buildings.

Images, UC QuakeStudies

An image encouraging people to take notice. The image depicts an 'All Rightie' in a fluorescent vest standing by a road cone and gazing at the night sky and reads, "When was your last moment of wonder? Sometimes the quietest moments can really change our perspective." The image was from phase 2 of the All Right? campaign, promoting the Five Ways to Wellbeing. The Five Ways to Wellbeing is a simple, evidence-based approach to improving wellbeing, promoted by the Mental Heath Foundation.

Images, UC QuakeStudies

Damage to Fitzgerald Avenue. The northbound lanes have collapsed towards the river, and a pile of rubble from the damaged road is heaped on the road. Road cones divert traffic onto the southbound lanes. The photographer comments, "Fitzgerald Avenue between Kilmore Street and Bealey Ave is a mess. Half of the road has slumped towards the river by a good metre or two. My brother-in-law was here when the 22nd earthquake hit and he said the damage wasn't as bad as this at first. A local resident told me that the road is slumping more and more each day".

Images, UC QuakeStudies

Damage to Fitzgerald Avenue. The northbound lanes have collapsed towards the river, and a pile of rubble from the damaged road is heaped on the road. Road cones divert traffic onto the southbound lanes. The photographer comments, "Fitzgerald Avenue between Kilmore Street and Bealey Ave is a mess. Half of the road has slumped towards the river by a good metre or two. My brother-in-law was here when the 22nd earthquake hit and he said the damage wasn't as bad as this at first. A local resident told me that the road is slumping more and more each day".

Images, UC QuakeStudies

Damage to Fitzgerald Avenue. The northbound lanes have collapsed towards the river, and a pile of rubble from the damaged road is heaped on the road. Road cones divert traffic onto the southbound lanes. The photographer comments, "Fitzgerald Avenue between Kilmore Street and Bealey Ave is a mess. Half of the road has slumped towards the river by a good metre or two. My brother-in-law was here when the 22nd earthquake hit and he said the damage wasn't as bad as this at first. A local resident told me that the road is slumping more and more each day".

Articles, UC QuakeStudies

A PDF copy of a design for a bus back encouraging people to take notice. The design depicts an 'All Rightie' in a fluorescent vest standing by a road cone and gazing at the night sky and reads, "When did you last get caught up in the moment? It's the simple things that bring us joy." The design was from phase 2 of the All Right? campaign, promoting the Five Ways to Wellbeing. The Five Ways to Wellbeing is a simple, evidence-based approach to improving wellbeing, promoted by the Mental Health Foundation.

Images, UC QuakeStudies

Damage to River Road in Richmond. The road is badly cracked and slumped, and is closed off with a row of road cones tied with warning tape. The word "closed" has been spray painted on the road surface. The photographer comments, "These photos show our old house in River Rd and recovery work around Richmond and St Albans. River Rd was again subject to severe lateral spreading. The river is still grey with silt, the road is ripped and sunken, and power poles lean at random angles. The red car belonged to a postie, who had to come back with a tow truck to extricate the car from the hole that had opened underneath it. Looking along River Road to the north-east. Taken outside 79 Medway St".

Research papers, University of Canterbury Library

Well-validated liquefaction constitutive models are increasingly important as non-linear time history analyses become relatively more common in industry for key projects. Previous validation efforts of PM4Sand, a plasticity model specifically for liquefaction, have generally focused on centrifuge tests; however, pore pressure transducers installed at several free-field sites during the Canterbury Earthquake Sequence (CES) in Christchurch, New Zealand provide a relatively unique dataset to validate against. This study presents effective stress site response analyses performed in the finite difference software FLAC to examine the capability of PM4Sand to capture the generation of excess pore pressures during earthquakes. The characterization of the subsurface is primarily based on extensive cone penetration tests (CPT) carried out in Christchurch. Correlations based on penetration resistances are used to estimate soil parameters, such as relative density and shear wave velocity, which affect liquefaction behaviour. The resulting free-field FLAC model is used to estimate time histories of excess pore pressure, which are compared with records during several earthquakes in the CES to assess the suitability of PM4Sand.

Research papers, The University of Auckland Library

The Canterbury region experienced widespread damage due to liquefaction induced by seismic shaking during the 4 September 2010 earthquake and the large aftershocks that followed, notably those that occurred on 22 February, 13 June and 23 December 2011. Following the 2010 earthquake, the Earthquake Commission directed a thorough investigation of the ground profile in Christchurch, and to date, more than 7500 cone penetration tests (CPT) have been performed in the region. This paper presents the results of analyses which use a subset of the geotechnical database to evaluate the liquefaction process as well as the re-liquefaction that occurred following some of the major events in Christchurch. First, the applicability of existing CPT-based methods for evaluating liquefaction potential of Christchurch soils was investigated using three methods currently available. Next, the results of liquefaction potential evaluation were compared with the severity of observed damage, categorised in terms of the land damage grade developed from Tonkin & Taylor property inspections as well as from observed severity of liquefaction from aerial photography. For this purpose, the Liquefaction Potential Index (LPI) was used to represent the damage potential at each site. In addition, a comparison of the CPT-based strength profiles obtained before each of the major aftershocks was performed. The results suggest that the analysis of spatial and temporal variations of strength profiles gives a clear indication of the resulting liquefaction and re-liquefaction observed in Christchurch. The comparison of a limited number of CPT strength profiles before and after the earthquakes seems to indicate that no noticeable strengthening has occurred in Christchurch, making the area vulnerable to liquefaction induced land damage in future large-scale earthquakes.

Research papers, The University of Auckland Library

During the recent devastating earthquakes in Christchurch, many residential houses were damaged due to widespread liquefaction of the ground. In-situ testing is widely used as a convenient method for evaluating liquefaction potential of soils. Cone penetration test (CPT) and standard penetration test (SPT) are the two popular in situ tests which are widely used in New Zealand for site characterization. The Screw Driving Sounding (SDS) method is a relatively new operating system developed in Japan consisting of a machine that drills a rod into the ground by applying torque at seven steps of axial loading. This machine can continuously measure the required torque, load, speed of penetration and rod friction during the test, and therefore can give a clear overview of the soil profile along the depth of penetration. In this paper, based on a number of SDS tests conducted in Christchurch, a correlation was developed between tip resistance of CPT test and SDS parameters for layers consisting of different fines contents. Moreover, using the obtained correlation, a chart was proposed which relates the cyclic resistance ratio to the appropriate SDS parameter. Using the proposed chart, liquefaction potential of soil can be estimated directly using SDS data. As SDS method is simpler, faster and more economical test than CPT and SPT, it can be a reliable alternative in-situ test for soil characterization, especially in residential house constructions.

Research papers, The University of Auckland Library

A number of field testing techniques, such as standard penetration test (SPT), cone penetration test (CPT), and Swedish weight sounding (SWS), are popularly used for in-situ characterisation. The screw driving sounding (SDS) method, which has been recently developed in Japan, is an improved version of the SWS technique and measures more parameters, including the required torque, load, speed of penetration and rod friction; these provide more robust way of characterising soil stratigraphy. It is a cost-efficient technique which uses a machine-driven and portable device, making it ideal for testing in small-scale and confined areas. Moreover, with a testing depth of up to 10-15m, it is suitable for liquefaction assessment. Thus, the SDS method has great potential as an in-situ testing method for geotechnical site characterisation, especially for residential house construction. In this paper, the results of SDS tests performed at a variety of sites in New Zealand are presented. The soil database was employed to develop a soil classification chart based on SDS-derived parameters. Moreover, using the data obtained following the 2010-2011 Christchurch Earthquake Se-quence, a methodology was established for liquefaction potential evaluation using SDS data. http://www.isc5.com.au/wp-content/uploads/2016/09/1345-2-ORENSE.pdf

Research papers, University of Canterbury Library

Semi-empirical models based on in-situ geotechnical tests have become the standard of practice for predicting soil liquefaction. Since the inception of the “simplified” cyclic-stress model in 1971, variants based on various in-situ tests have been developed, including the Cone Penetration Test (CPT). More recently, prediction models based soley on remotely-sensed data were developed. Similar to systems that provide automated content on earthquake impacts, these “geospatial” models aim to predict liquefaction for rapid response and loss estimation using readily-available data. This data includes (i) common ground-motion intensity measures (e.g., PGA), which can either be provided in near-real-time following an earthquake, or predicted for a future event; and (ii) geospatial parameters derived from digital elevation models, which are used to infer characteristics of the subsurface relevent to liquefaction. However, the predictive capabilities of geospatial and geotechnical models have not been directly compared, which could elucidate techniques for improving the geospatial models, and which would provide a baseline for measuring improvements. Accordingly, this study assesses the realtive efficacy of liquefaction models based on geospatial vs. CPT data using 9,908 case-studies from the 2010-2016 Canterbury earthquakes. While the top-performing models are CPT-based, the geospatial models perform relatively well given their simplicity and low cost. Although further research is needed (e.g., to improve upon the performance of current models), the findings of this study suggest that geospatial models have the potential to provide valuable first-order predictions of liquefaction occurence and consequence. Towards this end, performance assessments of geospatial vs. geotechnical models are ongoing for more than 20 additional global earthquakes.

Research papers, The University of Auckland Library

The Screw Driving Sounding (SDS) method developed in Japan is a relatively new insitu testing technique to characterise soft shallow sites, typically those required for residential house construction. An SDS machine drills a rod into the ground in several loading steps while the rod is continuously rotated. Several parameters, such as torque, load and speed of penetration, are recorded at every rotation of the rod. The SDS method has been introduced in New Zealand, and the results of its application for characterising local sites are discussed in this study. A total of 164 SDS tests were conducted in Christchurch, Wellington and Auckland to validate/adjust the methodologies originally developed based on the Japanese practice. Most of the tests were conducted at sites where cone penetration tests (CPT), standard penetration tests (SPT) and borehole logs were available; the comparison of SDS results with existing information showed that the SDS method has great potential as an in-situ testing method for classifying the soils. By compiling the SDS data from 3 different cities and comparing them with the borehole logs, a soil classification chart was generated for identifying the soil type based on SDS parameters. Also, a correlation between fines content and SDS parameters was developed and a procedure for estimating angle of internal friction of sand using SDS parameters was investigated. Furthermore, a correlation was made between the tip resistance of the CPT and the SDS data for different percentages of fines content. The relationship between the SPT N value and a SDS parameter was also proposed. This thesis also presents a methodology for identifying the liquefiable layers of soil using SDS data. SDS tests were performed in both liquefied and non-liquefied areas in Christchurch to find a representative parameter and relationship for predicting the liquefaction potential of soil. Plots were drawn of the cyclic shear stress ratios (CSR) induced by the earthquakes and the corresponding energy of penetration during SDS tests. By identifying liquefied or unliquefied layers using three different popular CPT-based methods, boundary lines corresponding to the various probabilities of liquefaction happening were developed for different ranges of fines contents using logistic regression analysis, these could then be used for estimating the liquefaction potential of soil directly from the SDS data. Finally, the drilling process involved in screw driving sounding was simulated using Abaqus software. Analysis results proved that the model successfully captured the drilling process of the SDS machine in sand. In addition, a chart to predict peak friction angles of sandy sites based on measured SDS parameters for various vertical effective stresses was formulated. As a simple, fast and economical test, the SDS method can be a reliable alternative insitu test for soil and site characterisation, especially for residential house construction.