Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 


UC engineering expert helping in Christchurch’s rebuild

UC engineering expert helping directly in Christchurch’s rebuild

December 4, 2012

University of Canterbury’s civil and natural resources engineer Professor, Misko Cubrinovski, is helping in the Christchurch rebuild by working with the Stronger Christchurch Infrastructure Rebuild Team (SCIRT) on repairing 2000 km of water mains and 2000 km of sub-mains.

His preliminary geo-spatial analysis of the damage data indicated that, on average, there was one break/fault per kilometre of damaged pipelines. Eighty percent of the damaged pipe networks were in soils that suffered liquefaction.

In addition, there are about 2000 km of wastewater pipes, of which nearly 700 km were either out of service or with limited service one month after the earthquake.

``We are continuing our collaboration and support of Christchurch City Council (CCC) and SCIRT engineers, designers and managers,’’ Professor Cubrinovski said.

`` We will pass our research outcomes to CCC and SCIRT in the course of the study and will continue to provide technical advice on a regular basis.

``Both the detail and the big picture are very important. Use of flexible pipe materials and joints that can accommodate large ground movements, trench and manhole details protecting the pipelines and minimising relative movements between the pipes and surrounding soils and many other engineering solutions that reduce damage and improve overall performance of the networks are required.

``However, this has to be achieved in a cost effective way and therefore we have to accept some damage, or even design the system to fail at a particular location where quick repair and reinstatement will be easily achievable.

``Large areas of Christchurch are susceptible to liquefaction of moderate to severe intensity. Since these networks are distributed across the city, their exposure to liquefaction hazards is very high.A robust and balanced approach is needed to provide an affordable system that will ensure good performance during earthquakes.

``This is well understood in CCC and SCIRT and there are many dedicated people who work very hard in achieving these goals. I have seen many excellent contributions and good stories of this nature, and UC is certainly making a very strong contribution in these efforts.’’

One of the projects Professor Cubrinovski led after the February 22 earthquake last year focused on the impacts of liquefaction on the potable water and wastewater systems of Christchurch. The project started in April last year and worked closely with a group of about 10 people from the CCC. The team started work on the rebuild even before SCIRT was established.

Before the earthquakes, very few people had any deep understanding of liquefaction and its impacts on infrastructure. The CCC and SCIRT engineers and Professor Cubrinovski had lengthy discussion about liquefaction, how it evolves during earthquakes, the resulting ground deformation and how it affects engineering structures and buried pipes in particular.

They discussed many details about the potable and wastewater pipe networks of Christchurch, for example, grading and density of backfills in trenches, characteristics of different pipe materials and connections.

There was an immediate need for CCC, and then SCIRT, to quickly start the reinstatement/recovery work on these lifelines and for that purpose they needed area-specific design criteria addressing liquefaction hazards. This, in turn, required zoning of Christchurch with respect to ground conditions and liquefaction susceptibility/severity.

``We quickly produced a so-called Liquefaction Resistance Index Map for Christchurch which identifies five different zones and for each zone specifies parameters (such as ground strains and displacements) that are used in the design of the networks. This map has been used as a principal tool by SCIRT engineers for preliminary screening in the design process.

``The map is unique because it provides back-calculated liquefaction resistance purely based on observations of manifested liquefaction and recorded ground motions. This is invaluable information because it synthesises all the complexities and specific characteristics of our soils and their response during actual earthquakes,’’ he said.

ends

© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Patience: Drive Safe

Be patient before passing is the AA's message for drivers this Labour weekend.

"People taking crazy risks to get past other vehicles is one of the most dangerous things on the road,” says AA spokesperson Dylan Thomsen.

“The weather is looking good for the long weekend so the roads will be busy. Unfortunately, that also increases the chances of people getting frustrated and trying a risky passing manoeuvre. When they get past, there will probably be more traffic up ahead anyway so it won’t get people there faster.” More>>

 
 

Parliament Today:

Employment Relations Bill: Govt Strains To Get Tea Break Law Through

The Government has been left with egg on its face - failing to get its much-vaunted, but hugely unpopular, meal break law passed in the first week of its new term, Labour spokesperson on Labour Issues Andrew Little says. More>>

ALSO:

Guns: Police Association Call To Arm Police Full Time

"The new minister gave his view, that Police do not need to be armed, while standing on the forecourt of parliament. The dark irony was that the interview followed immediately after breaking news of a gunman running amok in the Canadian parliament in Ottawa..." More>>

ALSO:

Gordon Campbell: On The Tokenism Of New Zealand's Role Against Islamic State

Our contribution against IS will be to send SAS forces to train the Iraqis? That’s like offering trainers to General Custer just as the 7th cavalry reached the Little Big Horn. More>>

ALSO:

Scoop Business: Shell And Todd Caught Drilling Without Approval

Multi-national oil company Shell’s New Zealand arm and local energy giant Todd Energy have breached the new law governing New Zealand’s Exclusive Economic Zone, the Environmental Protection Authority says in an Oct. 10 document released by the Green Party. More>>

ALSO:

Gordon Campbell: On Pharmac, Gough Whitlam And Sleater-Kinney

We’re not at the outset of these negotiations. The outset was six years ago, and negotiators were hoping to have some sort of ‘framework’ deal finished in time for the APEC meeting in a few weeks’ time. These ‘extreme’ positions are what we’ve reached near the intended end of the negotiations… More>>

ALSO:

PM Of Many Hats: Questions, No Answers On Whale Oil

Dr RUSSEL NORMAN (Co-Leader – Green) to the Prime Minister: How many times since November 2008 has he spoken with blogger Cameron Slater on the phone and how many times, if any, has he texted him?
Rt Hon JOHN KEY (Prime Minister): None in my capacity as Prime Minister. More>>

ALSO:

Aussie Investigation Dropped: Call On Minister McCully To Pursue The Case Of Balibo Five

West Papua Action is deeply concerned at the lack of any clear outcome from the Australian Federal Police inquiry into the 1975 deaths of the ‘Balibo Five’ including NZ journalist Gary Cunningham. More>>

ALSO:

'Feed The Kids' Bill: Metiria Turei To Lead Fight On Feeding Hungry Children

Green Party Co-leader Metiria Turei is urging all political parties to support the Feed the Kids Bill which she inherited today from Mana leader Hone Harawira. More>>

ALSO:

Parliament Today: State Opening Of Parliament

The House sat at 10.30am on Tuesday before MPs were summoned to hear the Speech from the Throne in the Legislative Council Chamber. More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news