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

Open Source // Open Society - Full Coverage

War: What’s To Commemorate?

Gordon Campbell in Werewolf: It is easy to know what we don’t want to commemorate on Anzac Day this year...

In fact, is there anything that can be validly commemorated on this 100th anniversary of Gallipoli?

Beyond, that is, a fleeting sense of empathy with the thousands of soldiers killed or wounded on April 25 1915 and in the months thereafter, until the whole thing was finally called off in December 1915.

(Most of the New Zealand survivors were transferred to the trenches in France, and eventually to the battle of the Somme in 1916.) More>>

 

PARLIAMENT TODAY:

Peter Ellis Case: Minister Declines Request For Commission Of Inquiry

Justice Minister Amy Adams has declined a request from supporters of Peter Ellis for a Commission of Inquiry on the basis that an inquiry cannot be used to determine the liability of any person. More>>

Quakes: New Process For Red Zone Crown Offers

Canterbury Earthquake Recovery Minister Gerry Brownlee has announced a process to give everyone a say on the Crown offers to owners of vacant, commercial/industrial and uninsured properties in the Residential Red Zone. More>>

ALSO:

Gordon Campbell: On The Battle Obama Is Waging Over The TPP

For the past two and a half years, this column has been arguing that the fate of the Trans Pacific Partnership (TPP) deal will hinge on whether US President Barack Obama can win Trade Promotion Authority (TPA) from Congress... Last week, the White House finally, finally unveiled a draft TPA Bill. More>>

ALSO:

Greens: Govt Breaks Free Doctors Visit Promise To Kids

Documents obtained by the Green Party show that the Government decided to fund only 90 percent of doctors’ visits for children suffering from an injury in an attempt trim the cost of the so-called “free” visits. More>>

ALSO:

Other Wars: Extension Of NZDF Commitment In Afghanistan

The New Zealand Defence Force’s commitment of mentors and support staff to the Afghan National Army Officer Academy in Afghanistan has been extended out to December 2016, Defence Minister Gerry Brownlee says. More>>

PM's Press Conference: Auckland Property Prices Increasing "Too Rapidly"

John Key accepted that Auckland property prices 'are going up too rapidly” in a press conference held today in Wellington, however he said that this is not anything new. More>>

ALSO:

Press Conference: ANZAC PMs Concerned About ISIL Bringing The War Home

Prime Minister Key and Prime Minister Abbott spoke of the bond formed between Australia and New Zealand in the “baptism of fire” of Gallipoli. Abbott stated that New Zealand and Australia’s values and interests are linked, and this is reflected in the joint operation in Iraq which will begin shortly. More>>

ALSO:

GCSB's China Shopping: Key Damages China Relationship

Evidence that the Key Government recklessly approved a GCSB spying operation to intercept Chinese diplomatic communications between offices in Auckland will pointlessly damage our relationship with China, the Green Party said today. More>>

ALSO:

Gordon Campbell: On The Reserve Bank And Auckland Housing

The ‘crisis – what crisis?’ response by the government to the Auckland housing price bubble is no longer acceptable. So says Reserve Bank governor Grant Spencer... More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news