Another major Wellington building closes due to Earthquake Risk

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jamesrt

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#248320 19-Mar-2019 19:21

This time, it's the Central Library and its carpark.

I think we (the people) should be asking questions of the council as to why this has happened only now. Surely if the building was unsafe this should have been discovered sooner. They'd already taken major steps (deconstructing the walkway bridge to the council building, for example); why wasn't this risk uncovered sooner?

And how many more buildings are there in the CBD that are an actual risk? How will we ever know?

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#2201952 19-Mar-2019 19:25

"The building is not damaged but the vulnerabilities identified using new guidelines from the Ministry of Business, Innovation and Employment (MBIE) are such that we have made the decision to close the building to the public and relocate our staff while next steps are planned."

The MBIE guidelines were only updated ~ November/December 2018 so this is a result of check-ups based on the new guidelines. It will be interesting to see how many other buildings now fail based on these updated guidelines. Things is that many don't need to get updated assessments so some will never know!

-- opinions expressed by me are solely my own. ie - personal

Coil

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#2201972 19-Mar-2019 19:50

Looks like a relatively recent building?
Interested to know what else will be on the chopping block. I am guessing it is a tilt slab? The issue was pre cast floors IIRC.

mattwnz

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#2201988 19-Mar-2019 20:04

Coil:

Looks like a relatively recent building?
Interested to know what else will be on the chopping block. I am guessing it is a tilt slab? The issue was pre cast floors IIRC.

I recall it was probably built in the early 90s, so quite new. It is not tilt slab, I recall it uses concrete frames like many buildings. At a guess, I am guessing they are worried about how the floors are tied to the frames. But there must be many buildings around that use this type of construction.

mattwnz

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#2201990 19-Mar-2019 20:07

jamesrt:

I think we (the people) should be asking questions of the council as to why this has happened only now.

My local council shut down our local library just last year after the library was found to also be unsafe, and it was closed for a year while it was strengthened.

wellygary

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#2202000 19-Mar-2019 20:21

mattwnz:

Coil:

Looks like a relatively recent building?
Interested to know what else will be on the chopping block. I am guessing it is a tilt slab? The issue was pre cast floors IIRC.

I recall it was probably built in the early 90s, so quite new. It is not tilt slab, I recall it uses concrete frames like many buildings. At a guess, I am guessing they are worried about how the floors are tied to the frames. But there must be many buildings around that use this type of construction.

Yeah, their big concern appears to be about the hollowcore floor segments slipping off the beams supporting beams, but they reckon its only 20% of NBS,

To fix it they will need to bolt steel frames between the floor and beams to tie them together and give more space to stop them falling...

"The most critical mechanism of failure has been assessed to be the potential loss of seating/support to the hollowcore units. The existing structural drawings indicate tha t the seating as specified typically ranges between 50 and 60mm. It is on this basis when allowance has been made for construction tolerances, and creep and shrinkage effects, that the hollowcore precast floor system at IL2 achieves a score of 20% NBS as assessed by the MBIE guidelines fo r assessing existing buildings. There are a large number of parameters included in the calculations to determine the score. A sensitivity study of those factors indicates that this range could potentially extend from 15% - 25 %NBS (IL2)"

https://wellington.govt.nz/~/media/services/community-and-culture/libraries/files/engineering-assessment.pdf?la=en

mattwnz

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#2202002 19-Mar-2019 20:26

wellygary:

Yeah, their big concern appears to be about the hollowcore floor segments slipping off the beams supporting beams, but they reckon its only 20% of NBS,

To fix it they will need to bolt steel frames between the floor and beams to tie them together and give more space to stop them falling...

But I suspect there are many buildings built this way. But listening to the announcement, it is because public building have a far higher standard they must reach, which I suspect is also why my local library was forced to close too.

allan

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#2202051 19-Mar-2019 21:27

3,000 people per day using it is a lot of people to put at risk if you just do nothing.

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PolicyGuy

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#2202114 19-Mar-2019 22:23

wellygary:

"... A sensitivity study of those factors indicates that this range could potentially extend from 15% - 25 %NBS (IL2)"

So the best you can hope for is 25% of NBS.

That is appalling, particularly in a recent* "prestige" custom designed, custom built public building

Has the NBS changed so much that what is now at best 25% was 100% thirty years ago? I very much doubt it.
So the building was probably never Building Code compliant from the day it went up.
Who was responsible? Was the architectural design by Ian Athfield deficient? Was the detailed engineering design or the actual construction by by Fletcher Development & Construction not up to scratch?

Sheesh

* According to http://www.wcl.govt.nz/about/branches/central/architecture.html "the firm of Athfield architects drew up the plans for a new library building ... The building was constructed by Fletcher Development & Construction and opened in December, 1991"

vexxxboy

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#2202128 19-Mar-2019 22:41

so the public are at risk but its ok for staff to work in there for the next few weeks to remove all the books etc but they are even stopping the public using the footpaths.

Common sense is not as common as you think.

Bung

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#2202158 20-Mar-2019 00:04

There's been no mention of clearing the books out. You could imagine that a lot of the popular books are already out of the building and will go back to the other libraries.

nickb800

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#2202179 20-Mar-2019 06:45

mattwnz:
wellygary:

Yeah, their big concern appears to be about the hollowcore floor segments slipping off the beams supporting beams, but they reckon its only 20% of NBS,

To fix it they will need to bolt steel frames between the floor and beams to tie them together and give more space to stop them falling...

But I suspect there are many buildings built this way. But listening to the announcement, it is because public building have a far higher standard they must reach, which I suspect is also why my local library was forced to close too.

The snipped quote above refers to 15-24% at IL2 - this is a 'normal' importance level that you'd expect for a house or office block. The assessment doesnt take into account the fact that it's a public building, but the council decision to evacuate probably does

gzt

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#2202181 20-Mar-2019 06:49

allan:
3,000 people per day using it is a lot of people to put at risk if you just do nothing.

Auckland has similar problems:

https://www.stuff.co.nz/auckland/105577817/nearly-2000-auckland-buildings-identified-as-earthquakeprone

Last time I heard the list of privately owned buildings affected was effectively secret. Imo if the risk is certain close them.

sbiddle

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#2202189 20-Mar-2019 07:25

I predict this turning into a much bigger issue - there are potentially hundreds of buildings from the late '80s right through to very recently that have similar construction techniques and suffer from the same potential failures.

The MBIE rules have come into play primarily because of Stats house and how that performed. That building may have survived fine in Christchurch, but the lateral forces from the Kaikoura quake were very different and have really given engineers something completely different to consider when constructing buildings. The beams and floors in the library meet 100% of NBS for some aspects of testing, but could fail in some areas should another similar quake happen - but could also be fine in a quake like Christchurch.

Engineering friends have been talking about this for a few months, and I really did wonder with the IAG announcement last week whether this was them pre-empting some sort of big announcement.

MikeB4

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#2202202 20-Mar-2019 08:25

sbiddle:

I predict this turning into a much bigger issue - there are potentially hundreds of buildings from the late '80s right through to very recently that have similar construction techniques and suffer from the same potential failures.

The MBIE rules have come into play primarily because of Stats house and how that performed. That building may have survived fine in Christchurch, but the lateral forces from the Kaikoura quake were very different and have really given engineers something completely different to consider when constructing buildings. The beams and floors in the library meet 100% of NBS for some aspects of testing, but could fail in some areas should another similar quake happen - but could also be fine in a quake like Christchurch.

Engineering friends have been talking about this for a few months, and I really did wonder with the IAG announcement last week whether this was them pre-empting some sort of big announcement.

I think IAG are getting nervous about the increasing talk of a major event concerning rupture of the Hikurangi subduction zone.

alasta

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#2202204 20-Mar-2019 08:27

I hope this isn't going to affect apartment buildings. If so a lot of people are going to find themselves in financial trouble, and the housing crisis is going to get a whole lot worse.

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