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Does everyone realize that Chiangmai sits on an earthquake fault line.

And that most of the city is built with concrete post and beam construction.

During earthquakes, these types of buildings are notorious for collapsing pancake

style.

If not total collapse, often the un-reinforced masonry infill walls tumble and crush

the residents.

How much concrete is over your head?

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You are indeed correct JRingo. That's why I spend my time on the top floor.

PS. One of the world's most densely populated areas in Southern California is also waiting for the big one. I guess we people are either very stupid, or eternal optimists. :o DS.

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This only just an hour or so's flight away. Maybe we should head for the hills :o

Yunnan quake kills 19, injures 100

Beijing (dpa) - An earthquake measuring 5.1 on the Richter scale killed at least 19 people and injured more than 100 Saturday in the southwestern Chinese province of Yunnan, the government said.

The earthquake sparked landslides and rockfalls, damaging hundreds of homes in Yunnan's mountainous Yanjin county as it struck at 9:10 am (0110 GMT) on Saturday, the provincial seismological bureau said.

bangkok post today

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Does everyone realize that Chiangmai sits on an earthquake fault line.

Yes, it's a commonly known fact here. Several earthquakes are recorded in Chiang Mai chronicles, including one that topped the superstructure of Wat Chedi Luang. A network of faults runs all the way west to Bagan, Myanmar, north to Yunnan and south into the Andaman Sea. Keep your health insurance up to date ...

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I did a seismic design review when constructing my new house. Does not cost much more to do it right the first time.

did it cost more in terms of materials and added construction as apposed to the conventinal Thai way etc? Is it essentially cross supports between posts?

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Foundation design was a large component of the engineering and cost. My background is geotechnical engineering, and I was not comfortable with seat of the pants spread footings. Concern was liquifaction, differential settlement, and bearing failure. I used 30 x 30 x 10m piles that increased the cost by about 0.5% This is really really cheap and worth the peace of mind.

Secondary concern was shear in the columns and walls. As you say cross bracing is one way to address this. Rebar in the walls is a good idea to prevent them from simply falling down. Quality control on concrete and steel is very important, and in fact I did not know there was "full strength" and Thai quality rebar - my workers were bitching over how difficult real rebar is to bend. Take concrete samples and submit them for testing so that the Contractor will not be tempted to skimp. If using precast floors, check the loading and end connections.

I used several other non-Thai methods that are code in most countries such as vented plumbing stacks and P traps on drains, grounded electrical system, GFI outlets, low E double glazing, insulation. Exterior walls are Cool Block brand polystyrene cored block, with a 50 mm air space between local brick interior walls.

Total cost with the engineering and extras was about 10%. A waste to some, but worth it to me.

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Aside from the Chedi falling down has there been any reported structural damage to any buildings? ever? If there are such reports is it possible to tell what type of construction is was? All brick structures are the worst but I've never seen a building in Thailand that was all brick. Two story reinforced concrete post and beam (like Thai style building) structures that are properly reinforced are actually very safe in earthquakes. The structural members might sustain some damage in a very severe earthquake but it is very unlikely that they would collapse.

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Aside from the Chedi falling down has there been any reported structural damage to any buildings? ever? If there are such reports is it possible to tell what type of construction is was? All brick structures are the worst but I've never seen a building in Thailand that was all brick. Two story reinforced concrete post and beam (like Thai style building) structures that are properly reinforced are actually very safe in earthquakes. The structural members might sustain some damage in a very severe earthquake but it is very unlikely that they would collapse.

Hmmm...here is some post and beam construction:

Th0013.jpg

http://www.air-worldwide.com/_public/NewsD...0035/Turkey.asp

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We sustained some structural damage in an earthquake way back in the late '70s. A few big cracks and broken tiles with a new 2 inch step in part of the house.

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Chownah

Part of the problem is the quality of the materials is questionable, quality control is usually non-existant, and the workmanship may be shoddy. One needs to keep a very keen eye on this, or hire your own Engineer to work for you, as the Contractor may have other intrests. Standard design is not the best and is easily rectified.

I would encourage anyone to have their architects or contractors design reviewed by an Engineer with an eye to structural issues and sesmic review. It really does not cost a lot to do it right.

One the other hand, if you live through it, just buy insurance. We are buying insurance for the new house today, and earthquake coverage is only 300 B per million/year. Not sure what this covers exactly and am about to find out.

We sustained some structural damage in an earthquake way back in the late '70s. A few big cracks and broken tiles with a new 2 inch step in part of the house.
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