
The majority of current procedures used to deduce liquefaction potential of soils rely on empirical methods. These methods have been proven to work in the past, but these methods are known to overestimate the liquefaction potential in certain regions of Christchurch due to a whole range of factors, and the theoretical basis behind these methods cannot be explained scientifically. Critical state soil mechanics theory was chosen to provide an explanation for the soil's behaviour during the undrained shearing. Soils from two sites in Christchurch were characterised at regular intervals for the critical layers and tested for the critical state lines (CSL). Various models and relationships were then used to predict the CSL and compared with the actual CSL. However none of the methods used managed to predict the CSL accurately, and a separate Christchurch exclusive relationship was proposed. The resultant state parameter values could be obtained from shear-wave velocity plots and were then developed into cyclic resistance ratios (CRR). These were subsequently compared with cyclic stress ratios (CSR) from recent Christchurch earthquakes to obtain the factor of safety. This CSL-based approach was compared with other empirical methods and was shown to yield a favourable relationship with visual observations at the sites' locations following the earthquake.
The New Zealand Shipping Federation says the government needs to take the resilience of ports seriously as the Kaikoura earthquake has shown the vulnerability of roading - and consider what their role is when auditing them. Annabel Young is the Executive Director of the NZ Shipping Federation. Canterbury University Professor of Geological Sciences Tim Davies, says improving and increasing the transport network through coastal shipping is essential.
The new Cabinet is reportedly considering a rebuild plan for the Christchurch Cathedral, damaged in the 2011 earthquake. Supporters of restoring the cathedral say the signs are promising.
Christchurch Mayor Lianne Dalziel has experienced her fair share of earthquakes as a resident, MP and then Mayor. She joins Checkpoint.
The EQC says it has enough staff and money in the kitty to respond to the latest earthquakes, despite still having work to do in Christchurch - five years after on.
Farmers in North Canterbury say the earthquake is another blow to a region which has battled drought and volatile lamb and dairy markets
Beverly Forrester farms near Harden which is down the road from Hanmer Springs. Road damage means she's cut off from the outside world, apart from her phone Beverly was caught up in the Christchurch earthquake, so the events of the last 24hrs have been quite trying for her.
The High Court has said 40 Christchurch homeowners wanting to take a class action against earthquake insurer Southern Response can move forward with their claim.
The founders of a post-quake farmers market in Christchurch have taken the idea to Kaikoura, and has set up shop in the earthquake hit town.
Firms can expect to pay more and wait longer to get goods delivered to their door following the North Canterbury earthquakes.
Two Kaikoura residents have been airlifted to Christchurch for medical treatment following the earthquake. Health Minister Jonathan Coleman says health services are managing.
Those repairing an earthquake damaged cliff in Christchurch have had to wrangle with home owners who don't want to sell, and relocating a rare flightless moth. Rachel Graham reports.
An investigation is continuing into the CTV site, where 115 people died in the Christchurch earthquake five years ago. Dr Maan Alkaisi, whose wife died in the collapse, is keeping a close eye on developments as engineers examine the site.
A backpackers with pod-styled units has opened near Christchurch Airport as the city continues to struggle with budget accommodation following the 2011 earthquake.
Christchurch's tourism sector is poised for a strong rebound five years after the Canterbury earthquakes, but tourist operators and leaders say there is still work to do.
Christchurch's earthquake rebuild authority, Regenerate Christchurch, has released a new report setting out a timeline for what to do with the land - but angry residents are calling for action.
The number of emergency psychiatric assessments in Christchurch has more than doubled since the earthquakes struck.
A new report has heavily criticised how the Ministry of Education handled the post-earthquake Christchurch school reshuffle nearly four years ago.
Christchurch council has asked its residents to tell it if earthquake repairs haven't been done so it can accurately assess their property's value.
Karen Brown reports from Chch, where there seems to be no end in sight for the mental health problems caused by the earthquakes
After being largely shut off to the public since the earthquakes, Christchurch's iconic Arts Centre is set to reopen its Great Hall to the public tonight.
Worries about the mental health impacts of the Canterbury earthquakes dominated a fiery meeting at Parliament today.
A world class centre for music and the arts has opened in Christchurch, after The Music Centre of Christchurch was damaged beyond repair in the 2011 earthquakes.
The agency in charge of fixing earthquake damaged pipes and roads in Christchurch was last night issued an excessive noise notice after keeping residents awake in the early hours.
The orange road cone has become a symbol of Christchurch since the earthquakes. Now two men and a trailer have the job of retrieving the hundreds of cones that have gone missing over the past six years.
Repair work on Christchurch's iconic Town Hall, badly damaged in the earthquakes, has nearly hit the halfway mark.
A class action taken by 40 Canterbury earthquake claimants against Southern Response heads to court tomorrow.
Forty Christchurch homeowners have headed back to court, as they seek to take a class action against earthquake insurer Southern Response.
Belinda McCammon tracks progress in Christchurch 5 years after the earthquake that killed 185 people
A decision on the future of Christchurch's red zoned land could be made within a year. That's the hope of the man at the helm of Regenerate Christchurch, one of two organisations charged with taking over the city's rebuild from the Earthquake Recovery Authority, which shuts its doors in just three days.