Learning from the Christchurch Earthquake

Written By: - Date published: 1:39 pm, September 11th, 2010 - 21 comments
Categories: Environment, housing, law - Tags:

In the wake of the Napier earthquake in 1931, a committee was formed that suggested new earthquake-proofing rules that eventually became the 1935 Building Code, which was implemented soon after the First Labour Government came to power.

The Wairapapa quake in 1942 caused damage in Wellington that took a long time to be fixed (due, in no small part, to the war). As a result, the First Labour Government created the Earthquake and War Damage Commission in 1945, as a form of (near) universal, affordable home insurance against force majuere events.

The threat of air raids, gas attacks, invasion, and earthquakes pushed the evolution of civil defence in the inter-war years with Civil Defence finally being founded as part of the country’s reaction to World War 2.

From disasters, we take lessons for the future. What lessons can we learn from the Christchurch earthquake?

I’ve suggested a couple already: making EQC cover truly universal by collecting it along with rates, rather than via insurance, and universal disaster income insurance through a tiny income levy about 1% the size of ACC levies.

It’s becoming clear that building rules will need to be looked at again too. Liquefaction was a major cause of damage in Christchurch (as it was in Napier). As you know by now if you didn’t know before, liquefaction occurs when loose, water-logged soil is shaken violently. The soil is compressed and the water is forced to the surface resulting in a lower ground level and layer of watery mud on top.

The Christchurch Council says that it went to court to try to block some of the worst-hit developments because it was concerned about the danger of liquefaction in a major quake but it was unable to successfully block them. That tells me the rules need strengthening.

We should look to the Netherlands for lessons. They don’t have the earthquake risk we do but virtually their whole country is sandy soil with a very high water table. If anyone knows about stable construction in these conditions, it’s the Dutch. What are their building standards to protect buildings against the risks of sudden settling? I understand that they compress the earth with vibrating machines then drive deep foundations.

Seems like that works against liquefaction too because a few New Zealand bridges and buildings have been built using those practices (ironically, maybe, the Christchurch Council has a very good map of areas exposed to liquefaction and how it can be countered – can’t find the link).

Maybe we need to strengthen the rules to make that kind of liquefaction-proofing a requirement.

21 comments on “Learning from the Christchurch Earthquake ”

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  1. Jenny 1
    11 September 2010 at 3:25 pm

    Finally.

    Gov’t to address Chch housing shortfall

    Prime Minister John Key says a paper outlining support options will be presented to Cabinet on Monday.

    Unfortunately the Minister of Housing Phil Heatley is still, so far, missing in action.

    Where ever Phil has been issuing his press releases from, someone should inform him, there has been an earthquake in Christchurch.

  2. Loota 2
    11 September 2010 at 3:49 pm

    All signs that Phil is seriously out of his depth and refusing to make decisions on the advice that he has been getting.

    Mommy, help!!!

  3. Searlo 3
    11 September 2010 at 5:03 pm

    Ecan has a very good map of the possible areas of liquefaction (put out c2003) and available here: http://ecan.govt.nz/publications/General/solid-facts-christchurch-liquefaction.pdf

    • Dennis 3.1
      13 September 2010 at 9:55 am

      While the original printed version of the map may have been very useful, the online version is absolutely USELESS with much of the key information invisible. I assume the original has a dark colored background but the online version has a white background so all we see online is white text on white background.

  4. Jenny 4
    11 September 2010 at 5:06 pm

    The first link I provided to that story carried by ZB has been withdrawn.

    Here is a link to a report carried by Yahoo on the Government’s planned Monday meeting to address the housing shortfall.

    Gov’t to address Chch housing shortfall

    I expect that Phil Heatley, as Minister of Housing with responsibility for New Zealand’s biggest landlord, Housing New Zealand Corporation, will table a report to Monday’s meeting on the current condition and future plans of HNZC in relation to the earthquake.

    Included in his report, Phil Heatley must reveal his Ministry’s plans for rapid expansion by HNZC to meet the pressing needs of those made homeless by the quake.

    Also as HNZC is responsible for housing people with complex needs such as, those with mental health issues, also included should be a full report on the condition of these properties.

    There are 72 properties like this in Christchurch, plus six women’s refuges, as well as a place for at-risk Christchurch youth, and 84 properties for those with intellectual or physical disabilities.

    Has there been any damage to these properties?

    What repairs will/are being done?

    Have any special needs tenants been made homeless?

    If there are, what is Heatley’s plan to rehouse these tenants?

    captcha – “mistaking” (for somebody who gave a damn)

    • Descendant Of Smith 4.1
      12 September 2010 at 10:01 am

      The problem with Housing New Zealand is that they don’t build homes for people with disabilities.

      They build the house and then Enable provide the funding for any changes that need to be made post build.

      It’s would be a good opportunity for the two organisations to get their heads together and build some suitable housing from scratch – you know with simple things like wide passageways for wheelchairs, wet areas for showering and so on.

      I’ve never been quite sure why HNZ can’t simply build a decent range of housing for disabled people – as long as they don’t build them in ghettos.

      It seems quite obvious that a lot of their clients will be disabled.

      The council shouldn’t be let off the hook either. There’s also a good opportunity to build some council housing for the elderly close to the CBD. With an aging population it makes much more sense to build some one and two bedroom units close to town rather than new subdivisions way out of town.

    • Jenny 4.2
      12 September 2010 at 2:44 pm

      .
      John Key
      Sun Sept 12, 2010:

      Housing Minister Phil Heatley would take a paper to cabinet tomorrow with options to accommodate people forced from their homes.
      “Certainly some accommodation will free up very, very quickly, but it won’t satisfy all of the demands and that’s something that we’re working on with other interested parties,” Key said.

      In this paper to be tabled tomorrow, – will the Housing Minister, Phil Heatley reveal a plan by HNZC to buy up the necessary number of vacant properties in good condition to house the homeless?

  5. RobertM 5
    11 September 2010 at 6:27 pm

    The lesson is that most of NZ is too shaky and volcanic for many types of long term development. That was appreciated as early as the early l930’s after the Napier and Murchison earthquakes. The decision at that time was to stop work on the Nelson railway on which huge progress had made thru the Buller gorge. It would inevitably have been destroyed by the l969 Inaguahua earthquake. The east coast line from Picton to Kaikoura was completed as a result.My own view is that sooner or later the Christchurch-Picton line will disapear into the sea as a result of a quake which is one of the reasons why I think a National rail system is not viable here. The system is too light, steeply graded and vulnerable to quakes and volcanoes in the North Island. It would be far wiser to stop patching up the Cook straight rail ferries and reintroduce a more substantial Lyttleton-Wellington route.
    The decision not to build the Nelson -Grreymouth line meant New Zealand would never really develop either heavy industrialy or as a mineral economy because without the Nelson -Buller rail the system lacks the capacity to move large volumes of coal the haul thr the Otira tunnel being too steep and long a route from the West Coast coal fields. The Otira tunnel and the steep line act as a bottleneck and the cost of rail freighting coast or other minerals from the coast is really too high to be economical. NZ ers do not see the truth of the Australian derision of Aeotearoa as the shaky iles.

    • RedLogix 5.1
      11 September 2010 at 7:33 pm

      NZ ers do not see the truth of the Australian derision of Aeotearoa as the shaky iles.

      Umm…and they laugh at Japan for the same reason?

      It would inevitably have been destroyed by the l969 Inaguahua earthquake.

      No more damaged than was the road, and just as repairable.

      The Otira tunnel and the steep line act as a bottleneck and the cost of rail freighting coast or other minerals from the coast is really too high to be economical.

      Yet somehow it’s more economical once the coal is shipped overseas? You’ve kind of lost me there.

      • ghostwhowalksnz 5.1.1
        12 September 2010 at 11:13 am

        The steepness of the line can be mitigated by adding extra locomotives or bringing in higher powered ones. ( I think the Chinese locomotives will solve this )
        The real capacity constraint is a single line. You see pictures of coal carrying lines in Australia that are 4 tracks to allow fast and slow trains in both directions.
        The export of coal is a fairly new thing for the Coast, however there was a large fleet of small colliers who served all the NZ ports up till the 80s when natural gas came in and town gas was phased out.

        • RobertM 5.1.1.1
          12 September 2010 at 4:40 pm

          I would judge the route from the Buller coalfields to Nelson about 60 kilometres shorter than railing to Lyttelton which would have made the coal exports rather more economical. The rail line through the Buller gorge and under the Spooner range would not have had tunnels longer than about 2 kilometres and would have been less a restriction than the 9 kilometre long steep Otira tunnel which now electrification has been removed is dangerous and difficult to operate with diesels.
          Two routes would have more than doubled coal volume capacity. The marginality of coal exports via the Otira route is illustrated that the Fay richwhite Tranz Rail originally accepted contracts for the coal export business that barely covered costs to get the business.
          Had the Nelson line not been stopped by the earthquake risk it would have been much easier to rail coal to the North Island and there would probably have been more coal powered stations and the North Island steam rail fleet would probably not have been converted to oil burning steam around l950. It is an interesting point that in the days of steam much high quality coal was imported into NZ from Australia and even the United States because of the low quality of Waikato coal.

    • Loota 5.2
      11 September 2010 at 8:14 pm

      Frankly, every land mass on Earth is the result of tectonic/volcanic activity either recent or some distant time ago and by this kind of reasoning your suggestion is inevitably going to be that we get off this planet.

      Who is to say that NZ won’t have another Krakatoa or Taupo but lets not live every aspect of our lives around that possibility.

      NZ ers do not see the truth of the Australian derision of Aeotearoa as the shaky iles.

      Is Shaky Isles better or worse than Thirsty Isles?

    • Martin 5.3
      12 September 2010 at 1:29 pm

      Progress on the Nelson Railway was hindered through its history by a reluctance by the national government to spend money on same. The small fleet of Wf class tank locomotives that serviced the line for much of its life were old and suffered higher than normal wear and tear from having to spend half their lives running coal bunker first on Nelson bound trains (no turntables on the line). There were also delays during the war years when labour was in short supply. The fact the railhead never got past Owen River has nothing to do with earthquake risk….the governments at the time saw other lines as more important and that’s where the money got spent.

      Your argument that New Zealand is too shaky and volcanic for long term development doesn’t hold water. Japan is of similar size to New Zealand and to a large degree its a geological analogue of New Zealand…both countries sit on plate tectonic margins and have earthquakes and volcanoes. Despite this, Japan manages to function quite happily as an industrialised nation.

      • RobertM 5.3.1
        12 September 2010 at 4:50 pm

        No you are quite wrong, a huge construction effort was made down the Buller River in the late l920s and around 1930, far past where the rails were actually put down, to drive the railway through.
        Substanitally the trackbed and foundations were completed almost to Murchison. At that time the line was very much the priority compared with the East coast route to Picton. The reason work was stopped was because of the assessment of the geological instablity and earthquake risk, that is a fact. The relative importance of the work is shown by the fact a Royal train ran on the line around 1928 for the Duke of York. There are historic photos of the huge work that was been putting in thru the Buller Gorge in the late 1920s

  6. tsmithfield 6
    11 September 2010 at 8:52 pm

    I know several people with houses that have stood up well in areas subject to liquification. What has saved these houses is that they have foundations that are piled into underlying solid strata. So, perhaps for any rebuilding in these areas piling should be mandatory.

  7. Lanthanide 7
    11 September 2010 at 10:13 pm

    My dad (masters in geology, studied port hills for his project) says that when the alpine fault goes, the shaking will likely last for 2-3 minutes non-stop. It’ll probably be about the same strength as what we’ve just had, but with a stronger sideways motion. The increased duration will significantly increase liquefaction in the city. Also, the west coast will be screwed, as the road links to Canterbury will be impassable for some time afterwards (likely months).

  8. kevyn 8
    14 September 2010 at 4:13 pm

    The fault rupture is unlikely to extend more than a few km north of Inchbonnie so the Lewis should only be closed for a few days max. Although, if the Alpine Fault is a super-sheer then you can add Nelson and Blenheim to the list of towns that will be screwed.

    I can’t see us having hovercars in the short time remaining till the next quake. Unless there’s a drastic change in government policy I can’t foresee any of the at-risk bridges getting seismic retrofits in time either.

  9. Swampy 9
    26 September 2010 at 1:32 am

    The rules are pretty strong but for some strange reason the CCC didn’t enforce any. Go north to Waimakariri District with the Pegasus Town development and rules were written in to ensure that the ground was strengthened and the houses had pile foundations so they withstood the shaking, result is much less damage than some of the liquefacted areas.

    The fact is that every few years there is another scandal where a council has allowed development on unsuitable land, a few examples coming to mind in the city include contaminated land on an old tip, and an old sawmilling pit full of sawdust that was built over resulting in severe subsidence with damage to houses etc.

    Now given that Labour has reformed the local government legislation a few times in the last 30 years you have to wonder why it is they have not placed any obligations on local councils to ensure that standards are met.

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