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

Werewolf Issue #49: Gordon Campbell Interviews Laila Harre

For 25 years, Labour and National have been in virtual agreement about the basics of economic policy, and differed mainly on how to go about managing its social consequences.

Such is the power of the economic orthodoxy that when opposition parties arise – say, in the shape of the Greens – their “credibility” is measured by the extent to which they give the appearance of learning and abiding by the ruling consensus.

The tension between the desire for change – and the inability of the current political framework to deliver it – creates openings for populists of all stripes. It is what has made the emergence of Internet Mana so interesting. More>>

 

Parliament Today:

Gordon Campbell: On National’s Electorate Deals

For all the talk yesterday from Prime Minister John Key about National being transparent about its electorate deals in Epsom and Ohariu, that transparency is entirely front-loaded. More>>

ALSO:

Greens: Oil Drilling Face-Off With Labour

The key policy points in the Green Party’s plan to protect our beaches from oil spills are to:
1. Prohibit deep sea oil drilling; 2. Implement compulsory shipping lanes for coastal shipping; 3. Build Maritime New Zealand’s oil spill response capability; and 4. Introduce a stronger legal framework so that when accidents do happen, the New Zealand taxpayer does not have to pay for the clean-up. More>>

ALSO:


Nick Smith v Fish & Game:

Minister Told Of FBI Investigation, Says INZ: Coleman Must Quit Or Be Sacked Over Dotcom Case - Harré

Immigration New Zealand has done the right thing in distancing itself from Jonathan Coleman’s claims that ministers were not aware of FBI involvement in Kim Dotcom’s residency application, says the Internet Party. More>>

ALSO:

Valedictory Season: Maori Party Founders Say Goodbye

Two major Maori MPs gave there farewell speeches to Parliament Thursday outlining their history, experiences, triumphs and regrets. More>>

ALSO:

Resignation Not Accepted: Transport Minister Breaches Aviation Security Rules

"Running late for a plane at Christchurch Airport, I without thought breached airport and airline security rules by entering the gate lounge through a door usually used for exit only..." More>>

ALSO:

TAIC Report: Urgent Recommendations After Melling Rail Accident

The Transport Accident Investigation Commission has made four urgent recommendations to KiwiRail following the accident two months ago (27 May) when a Matangi passenger train collided with a stop block at Melling Station, Lower Hutt. More>>

ALSO:

Red Tape: Local Regulations Go Under Microscope

The Government says it is accepting nearly all of the recommendations the Productivity Commission has made on ways to improve local regulations. More>>

ALSO:

Spending Questions: Claudette Hauiti To Step Aside At Election

National Party President Peter Goodfellow confirms that he has received notification from List MP Claudette Hauiti that she plans to step aside at the 20 September election. More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news