Buildings In Parts Of Thailand At Risk Of Collapse

[webfact]

Buildings at risk of collapse

By Pongphon Sarnsamak

The Nation

Quakes most likely in west and northern regions

Western and northern parts of Thailand could face severe damage - including building collapses, according to geologists, who say there are active faults in these areas that could cause earthquakes of about 6 on the Richter scale.

"We are now keeping an eye closely to monitor western and northern regions, as there are active faults in these areas," Mineral Resources Department spokesperson Adichart Surinkham said yesterday.

According to an earthquake risk map produced by the department, there are 13 faults in Thailand across some 22 provinces.

Kanchanaburi, Mae Hong Son, Nan, Phayao, Chiang Mai and Chiang Rai are classed as highly vulnerable to a quake of up to 7 on the Richter scale.

These provinces are located near three active fault lines, called Three Pagodas Pass, Srisawat, Mae Chan.

Kanchanaburi province is located near Three Pagoda Pass and Srisawat fault lines, while Mae Hong Son, Nan, Phayao, Chiang Mai and Chiang Rai are near the Mae Chan fault.

Adichart said that quakes with an epicentre in Burma or Laos would also affect Thailand, while a quake in the western region would affect Bangkok.

"An earthquake around 7 on the Richter scale would cause building collapses and road damage," he said.

"Unfortunately, nobody can say when they will exactly occur," he added.

Asian Institute of Technology seismologist Dr Penneung Wanichchai said the western and northern parts of Thailand were the "locations of concern" in Thailand as moderate quakes measuring 5-6 on the Richter scale were still occurring.

"We have found that the violent earthquake [centred near Tachilek in eastern Burma] is still active in these areas."

However, he said there was no earthquake source or fault line likely to cause severe damage and building collapses in Bangkok. But an earthquake with an epicentre outside the capital would affect buildings in Bangkok.

Pornthep Techapaiboon, the deputy governor of Bangkok Metropolitan Administration (BMA), said about 60 buildings with over 30 floors in Bangkok were at risk from an earthquake rating 5-7 on the Richter scale, such as Baiyoke Tower, the Dusit Thani Hotel, MBK department store, and commercial buildings located in Silom, Sathorn, and Wireless Roads.

Moreover, about 2,000 old buildings in Bangkok would be at risk from a large quake as they were constructed before the enforcement of the 2007 Building Control Act.

"We need to install protection for buildings against earthquakes," Pennueng said.

Given that earthquakes are natural events not yet able to be reliably predicted, National Disaster Warning Centre chief Group Captain Somsak Kowsuwan said his agency had been educating members of public about earthquake preparedness, particularly in areas most at risk of a severe earthquake.

"We found that many people are not aware about earthquakes. They even do not know what they will do after a quake," he said. "We have conducted a lot of training to practice earthquake preparedness but few officials have participated in the training."

-- The Nation 2011-03-29

[londonthai]

"about 60 buildings with over 30 floors in Bangkok were at risk from an earthquake rating 5-7 on the Richter scale, such as Baiyoke Tower, the Dusit Thani Hotel, MBK department store, and commercial buildings located in Silom, Sathorn, and Wireless Roads. ... We need to install protection for buildings against earthquakes"

it's a lot of big and expensive buildings at risk. Architects did not know, that earthquakes do happen in this neck of the woods?

interesting to see how the fault can be fixed

[chmiroau]

Real big problem here. In Kanchanaburi there is a really big dam, beautiful it is, right near Erawan Water Fall.

Should an earthquake hit somewhere near this dam, it could easily damage the dam wall sufficiently to cause the wall to fail. If this happens then the problem will most likely be huge.

There are thousands of people living in the shadow of this dam, reliant on for clean(er) water for living and for their crops. This will also cause problems for Thailand's already struggling hydro electric power.

Maybe this new news will provide enough incentive for the people in control of the dam to ask, plead for assistance to repair the damage.

Edited March 29, 2011 by metisdead
Reference to HM the King removed per rule #2.

[bbradsby]

HIgh rise design for windloads - a lateral force similar to earthquakes - should easily protect BKK's well-built skyscrapers from catastrophic failure for distant quakes in the North & Western regions, as well as any small quakes that would be more likely in the capital itself. The amateur-built low- to mid-rise concrete structures found across Thailand are the scary ones.

Unfortunately, as in all countries historically, it seems to take a disaster with a large loss of life for laws to be changed, building codes updated, and actual enforcement to begin to take place. Only at these junctures is building safety prioritized, and this unfortunately would suggest that Northern & Western Thailand communities are in line for a serious disaster at some point in the future when their maximum anticipated seismic events take place.

[1219patrickm]

Just hope not to be in country when a 6-7 lights off. I don't think there will be many safe places in BKK or Pattaya. I always wondered how many fault lines ran through Thailand. Looks to be a lot more than I would have imagined. They have almost the same amount as we have here in California.

[sirchai]

"about 60 buildings with over 30 floors in Bangkok were at risk from an earthquake rating 5-7 on the Richter scale, such as Baiyoke Tower, the Dusit Thani Hotel, MBK department store, and commercial buildings located in Silom, Sathorn, and Wireless Roads. ... We need to install protection for buildings against earthquakes"

it's a lot of big and expensive buildings at risk. Architects did not know, that earthquakes do happen in this neck of the woods?

interesting to see how the fault can be fixed

Moreover, about 2,000 old buildings in Bangkok would be at risk from a large quake as they were constructed before the enforcement of the 2007 Building Control Act.

2,000 buildings? Guess they forgot one zero........:jap:

[james24]

Propoganda. two exact same stories from same place on same day just different titles

Sure it can happen but there was close enough to a 7 here the other day and everything was relatively ok. It depends on the depth of the quake as much as it does on the richter number.

Watch how prices go up now

[tigermonkey]

HIgh rise design for windloads - a lateral force similar to earthquakes - should easily protect BKK's well-built skyscrapers from catastrophic failure for distant quakes in the North & Western regions, as well as any small quakes that would be more likely in the capital itself. The amateur-built low- to mid-rise concrete structures found across Thailand are the scary ones.

Unfortunately, as in all countries historically, it seems to take a disaster with a large loss of life for laws to be changed, building codes updated, and actual enforcement to begin to take place. Only at these junctures is building safety prioritized, and this unfortunately would suggest that Northern & Western Thailand communities are in line for a serious disaster at some point in the future when their maximum anticipated seismic events take place.

While there is some similarity in the resultant lateral forces causing swaying of the structure, either by earthquake movement or wind effect, I fail to see how "high rise design for windloads" makes the foundation adequate to withstand earthquakes.

Shaking is not the biggest problem for Bangkok highrises during an earthquake,but rather the liquefaction of ground under the structure. Most of Bangkok is built on up to 30 metres of silt, which becomes like quicksand during an earthquake. If the foundation/pilings are not designed to stay in place during liquefaction, the entire structure topples or sinks.

There are examples in Japan of structures falling over virtually intact as a result of liquefaction.

Edited March 29, 2011 by tigermonkey

[bbradsby]

HIgh rise design for windloads - a lateral force similar to earthquakes - should easily protect BKK's well-built skyscrapers from catastrophic failure for distant quakes in the North & Western regions, as well as any small quakes that would be more likely in the capital itself. The amateur-built low- to mid-rise concrete structures found across Thailand are the scary ones.

Unfortunately, as in all countries historically, it seems to take a disaster with a large loss of life for laws to be changed, building codes updated, and actual enforcement to begin to take place. Only at these junctures is building safety prioritized, and this unfortunately would suggest that Northern & Western Thailand communities are in line for a serious disaster at some point in the future when their maximum anticipated seismic events take place.

While there is some similarity in the resultant lateral forces causing swaying of the structure, either by earthquake movement or wind effect, I fail to see how "high rise design for windloads" makes the foundation adequate to withstand earthquakes.

Shaking is not the biggest problem for Bangkok highrises during an earthquake,but rather the liquefaction of ground under the structure. Most of Bangkok is built on up to 30 metres of silt, which becomes like quicksand during an earthquake. If the foundation/pilings are not designed to stay in place during liquefaction, the entire structure topples or sinks.

There are examples in Japan of structures falling over virtually intact as a result of liquefaction.

There are examples of liquifaction-caused buildings 'capsizing' into alluvium all over the place. Makes for nice photos! But I believe (as an architect from a very active Seismic Zone 4, but not a struct engineer) sinking a building requires large seismic event, with long duration, not the babies that BKK is mapped for. Also, the liquifaction maps I've seen place highest risk in sandy deposits and not the sticky, clayey silt I've seen in the Chao Phraya valley. But you may know better, and I'd love to hear about it. But getting back to the big events required for liquifaction, thankfully they won't occur in or near BKK according to the shake maps.

Back to that lateral - windloading issue, which I believe controls in BKK... I'm referring to BKK's modern high rises, whose foundations should be able to easily withstand a moderate event's lateral forces (this due to the windloading lateral resistance), as well as the expected moderate vertical shaking anticipated in the BKK region. No crystal ball here, but we should be ok in/near the capital unless they find a new, local fault that is capable of a significant seismic event. The risk maps show otherwise. Chiang Mai, well thats another kettle of fisk.

[bangon04]

Unfortunately, as in all countries historically, it seems to take a disaster with a large loss of life for laws to be changed, building codes updated, and actual enforcement to begin to take place.

It hasn't made much difference to road safety enforcement in Thailand, which kills thousands every year, so what makes you think there would be a real change in attitudes to building regs?

[dumball]

Do not know why they are talking of structures failing during an earthquake , why not start with something more simple , the hundreds of homes that collapse during a mere thunderstorm accompanied by some flooding ? My goodness ,even poorly constructed roads have been washed away in the recent rash of flooding , is this the first time they have heard about the damage an earthquake can do ?

[bbradsby]

Unfortunately, as in all countries historically, it seems to take a disaster with a large loss of life for laws to be changed, building codes updated, and actual enforcement to begin to take place.

It hasn't made much difference to road safety enforcement in Thailand, which kills thousands every year, so what makes you think there would be a real change in attitudes to building regs?

Purposeful optimism, and a bit of history. Periodically, human calamities related to poor building practices occur which are so horrendous that an outpouring of public sentiment creates incremental changes to the Codes. Next thing ya know, there are real Codes and actual inspectors with paid day jobs. And as a bureaucracy tends to not ever get smaller, the thing takes on a life of its own.

The history of building codes all over the world is one of incremental upgrades after each building-related catastrophic loss of life... after WTC fell, US code officials started looking at dedicated firemens' lifts, whereas Petronas Towers had them in 1998... following the British Code!

[londonthai]

Do not know why they are talking of structures failing during an earthquake , why not start with something more simple , the hundreds of homes that collapse during a mere thunderstorm accompanied by some flooding ? My goodness ,even poorly constructed roads have been washed away in the recent rash of flooding

because it's not only those 60 high tech buildings, which might fall down (each worth hundreds of millions), but hundreds and thousands of people in each of them. Falling debris of 30+ skyscraper in the densely populated area might kill further hundreds and thousands in the houses below and on the street level.

during flush floods people have time to move to the higher floors or grounds and not many lives are lost, only very few houses do collapse (unless there is a landslide) and rural roads can be repaired within weeks/months.