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

Budget '17: Budget Spends Down Future Surpluses

Tax cuts for every working New Zealander, targeted to low and middle income earners, more generous assistance for families and renters, and a massive spend-up on public services infrastructure mark Finance Minister Steven Joyce’s election year Budget.

The package of changes to income tax thresholds, the Working for Families programme, and the Accommodation Supplement is the Budget’s political centrepiece and will cost $2 billion a year. More>>

Scoop Full Coverage: of Budget Announcements & Reaction
Latest: Scoop Search

ALSO:

 
 

Auditor-General Stands Down For Investigation: Gordon Campbell On (Not) Taking Responsibility

So Martin Matthews, our current Auditor-General wishes he could have detected “earlier” the fraud that occurred on his watch at the Ministry of Transport. Hmmm. But he could have detected it earlier, surely? That’s the point. More>>

ALSO:

NGOs Pleased: Govt To Halt Collection Of Client Data

Brenda Pilott, the chair of ComVoices and national manager of Social Service Providers Aotearoa, congratulates the government on its decision to call a halt to the collection of individual client data until the concerns of not-for-profit service providers have been worked through. More>>

ALSO:

Gosh: Blasphemy Law Repeal Struck Down

Chris Hipkins, the MP who tabled a Supplementary Order Paper to add our Blasphemy Law to the Statutes Repeal Bill, said this was a "sad day for freedom of speech, tolerance, and leadership". More>>

ALSO:

Gordon Campbell: On The Navy’s Dealings With Fat Leonard, And Twin Peaks

At an official level, our “she’ll be right” attitude routinely spills over into a keen resentment of anyone who suggests the outcomes may be less than satisfactory… The Navy has now gone one step beyond. It won’t even ask itself whether it did a good job. More>>

ALSO:

NZDF: Fifth Rotation Of Troops Heads To Iraq

The fifth rotation of New Zealand Defence Force troops left today for a six-month mission training Iraqi soldiers. More>>

ALSO:

Gordon Campbell: On The Demonising Of Iran

Will New Zealand still be willing to pursue its recent trade overtures to Iran, now that US President Donald Trump has used his speech in Riyadh to single out Iran as the main source of terrorism and instability in the Middle East? More>>

ALSO:

 
 
 
 

Opening The Election Supporters

 

LATEST HEADLINES

  • PARLIAMENT
  • POLITICS
  • REGIONAL
 
 

Featured InfoPages

Opening the Election
 
 
 
  • PublicAddress
  • Pundit
  • Kiwiblog