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Saturday, January 7, 2012

Geotechnical earthquake engineering practice

The New Zealand Geotechnical Society have produced a publication called Geotechnical earthquake engineering practice:  Module 1 – Guideline for the identification, assessment and mitigation of liquefaction hazards . It was published in June 2010 as a draft with a one year period for comments. There is no sign of an updated version so it may, or may not, be up to date.

The publication arose from a desire to bring uniformity of practice within New Zealand by producing guidelines. It is a technical document, very much so in some parts, but does give some idea of what procedures are used in assessing land and how these procedures are carried out. Also useful for the lay person in TC3 areas. What you don't understand from this document may be the basis for asking questions when site specific assessments are to be done.

It can be downloaded from their website here.
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Friday, January 6, 2012

Science based earthquake update

GNS scientists and Tonkin & Taylor specialists this afternoon briefed city councillors and local members of parliament on the  latest information available for earthquakes in the region, and what might be expected to occur in the future.

Information from the briefing can be found on the following websites:
  • TV3 News live-streamed the presentation and have it available thorough video on demand links on the page here.
  • The council's Youtube channel has some of the presentations here.
  • Tsunami information is available here (the very remote possibility of a tsunami was discussed)
  • An FAQ and copy of the presentation slides are available from here.
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Thursday, January 5, 2012

Parklands and it's zoning.

In today's Press (here) a geotechnical engineer from Tonkin & Taylor states there are no engineering grounds for reclassifying Parklands as a Red Zone. The same engineer is quoted as saying the land in Parklands is "much better than in the red zones".

This may, or may not, be the case, however there is no conclusive evidence either way. Nothing has been made public about the state of the land under Parklands, nor Kaiapoi or anywhere else for that matter, which would show the truth and substance of the comments. 

It is not sufficient to state land is Red or Green on the "trust us we know what we are doing" basis. There is diminishing trust and increasing uncertainty that experts do know what they are doing and saying. The earthquakes and damage done are without precedent in New Zealand. Similarly there is little known about the way the land beneath Christchurch will behave in the future, be that tomorrow, next year, or some years hence. This is not the environment for agencies to be making unequivocal statements without backing them up with supporting evidence.  Confidence is needed that a commitment to repair or rebuild is a wise thing to do. In some areas, including Parklands, this confidence is not high.

CERA have said they will revisit the zoning of Parklands. Who will be undertaking the review? Will some external agency review both the data and the conclusions? The Earthquake Royal Commission has been using this approach to peer review reports from witness agencies to ensure what they say can withstand scrutiny. Such a procedure would bring more expertise to bear on the Parklands issue, and credibility to the outcome.

Ultimately the only thing that can remove doubt and suspicion is public scrutiny of both the factual findings made through geotechnical investigations, and the interpretation put on those results.
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Wednesday, January 4, 2012

Whats on your mind? - CanCERN want to know

CanCERN, of which our society is a member, is an organisation with good track record of trying to sort out the large problems that affect many of us. Considering it has a staff of only two what is achieved is very impressive.

CanCERN meets regularly with CERA, CCC, EQC and insurers. To make these meetings more productive CanCERN need to know the range of issues and questions experienced in the different parts/zones of the city.

On their website is the Whats on your mind? page. Here you can register your issues and thoughts. It is anonymous, confidential, and open to everyone. The information gathered will be used as preparation and background for the meetings. Please help them out by providing whatever information you can. The page is here.
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Tuesday, January 3, 2012

Orange Zone announcements - February

The New Zealand Herald has an article (here) based on a Radio New Zealand interview with Roger Sutton (8.00 news this morning). In that interview Sutton states that Orange Zone decisions will be announced in February. Considering previous comments mentioned "early in the new year" that is stretching the timetable somewhat.

Why decision making is taking so long is impossible to understand from the limited amount of information available. In the Avonside area the understanding has been that decision making is taking a great deal of time because of the need to obtain more technical information. Yet, looking at the Tonkin & Taylor Avonside factual reports put out by EQC just before Christmas (details here), little additional work has been carried out since June.

Appendix A of the Avonside report contains a map showing where the additional testing took place. Only five additional tests were carried out in what remains of the Orange Zone, the majority were outside it. Most noticeable is that these five tests were on the perimeter of the Orange Zone, none were carried out in the worst hit parts of Retreat Road or in Cowlishaw Street. As people in Retreat Road have been told delays to rezoning were because further tests were required, there appears to have been a huge gap between what was said and what was happening.

With the Parklands rezoning looking like a significant mistake, and the apparent lack of additional land testing in Avonside, any decision is going to be under a cloud of suspicion unless accompanied by all the information that supported the decision. Releasing the Cabinet Papers on the day of the announcement would go part way towards correcting this. Cabinet Papers for the rezonings announced on the 17th of November have yet to be released which implies a reluctance to have these difficult decisions examined.

What is most important right now is leadership that will explain in full detail the point decision making has reached, what else needs to be done, when it will be done, the problems that remain, and above all an indicative date for the rezoning announcement.
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Sunday, January 1, 2012

Happy new year

Happy new year one and all. Please spare a thought for those who went north for a quiet time and got soaked.

Unless something significant happens, the next post will be on the 4th.
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