Suvarnabhumi Airport Runway Crisis Deepens

[MEL1]

MEL 1

The sub-surface will get worse, if water dispersion continues. The sub-waters are actually an asset at the moment, as they hold the supporting the supporting materials, and in this case a lot of sand. Once the waters start to disperse that's when the supporting materials develeop major holes, and holes in them disappear. This is all a normal part of subsidence. It's not a normal function to use limestone and sand as supporting matter for an airport runway, on a swamp. The virginal pressures of when built, to now, will have been dispersed and we are just seeing the initial results of that over the last years. There is the propensity for sinkholes the size of football fields and 40m deep to occur at any time if a large water dispersion occurs. You only have to look at the major sinkholes that have occured in Florida, with houses and pools disappearing, in one case a sink hole 100m deep occured and took a building block to get an idea.

-mel.

Or it could be a bitumen surface problem.

Well I agree what you say has some merit. How ever is not the whole area (Bangkok) sinking to below the sea level and would not each little bit of sinking make the chances of the water leaving the area and creating huge sink holes less likely to happen.

With my experience in road building I would not have even attempted to build a airport of that size there as there is no way of getting proper compaction on a area that big.

But the one thing I did learn was that engineers had ways to work around some difficulties that would not occur to the normal person.

Don't get me wrong I have had my differences of opinion with them and been right on occasion but not all the time.

Just found this very short interesting study, which also mentions BKK.

http://wwwrcamnl.wr.usgs.gov/rgws/Unesco/PDF-Chapters/Chapter1.pdf

-mel.

[MEL1]

Let us build a F1- circuit!!!!

We have one it go's all the way around the moat. Exiting to watch during songkrahn. Does any one know what Tsongkhapa is? I got that on my spell checker when I checked Songkhran.

He was a Tibetan Buddhist.

-mel.

[redroo]

Just use waterski's on the landing gears...much cheaper too

[BwindiBoy]

You can see why Number One didn't want it named after him or his family.

They tend to name some airports after people once they are dead. Charles De Gaulle, Dulles & Ronald Reagan International come to mind.

So maybe in years to come, there may be planes landing at Shinawatra International Airport.

Surely Shinawatra Hub International Trade Airport - encapsulating his influence and the pivotal role Thailand plays in keeping South East Asia functioning...!?!

On a more serious note, the priority has to be safety. If that is achieved by continual inspection, closure and repair of runways so be it - as long as a rigid programme is in place. On the other hand, if that can only be achieved by completely rebuilding each runway, that should happen. Whayever they do they just need to be sure it's safe.

[Rob8891]

You can see why Number One didn't want it named after him or his family.

They tend to name some airports after people once they are dead. Charles De Gaulle, Dulles & Ronald Reagan International come to mind.

So maybe in years to come, there may be planes landing at Shinawatra International Airport.

....or maybe in the Shinawatra Hub International (Thailand)......

[Rob8891]

You can see why Number One didn't want it named after him or his family.

They tend to name some airports after people once they are dead. Charles De Gaulle, Dulles & Ronald Reagan International come to mind.

So maybe in years to come, there may be planes landing at Shinawatra International Airport.

....or maybe in the Shinawatra Hub International (Thailand)......

dam_n!..... beaten by seconds

[p_brownstone]

And Swampy gets 200 times more heavy traffic than Utapao every day, maybe even more. Oh and yes the US built it

And traffic is not necessarily the cause of sink holes, poor design and forethought is. At that time, B-52's fully loaded are 'heavy' and daily traffic was high but still nothing happened.

When Utapao was used by the US Airforce, yes the 'B-52's were heavy when they left but they were a d@mn lot lighter when they hit the pavement coming home.

Patrick

Edited July 7, 2012 by p_brownstone

[PingandSingh]

Com'on guys, what are you talking about?

Thais know exactly how to setup those monstrous things.

Wait until the 300km/h high-speed train between BKK and CNX will transport 2.000 people at a time.

They need 3 years only to finish that job. Just as they need a fraction of our time only to walk around with a master or another degree.

Be confident as they know all time what they doing.

[swillowbee]

... a degreed civil engineer here... structural ... don't know it all, but do know a good bit about the subject.

... without inspecting the damages, we can only speculate on causes of the Suvarnabhumi runway failures ... but, this does not sound favorable for the AOT and Thailand's reputation as a nation capable of achieving international standards.

... a few observations ... basics:

• Concrete does not flex well... it is designed to sustain tremendous compression loads, so dropping a fully loaded A380 at 200 knots onto its surface is no problem for properly designed and constructed concrete runways; however,
  
• When subject to significant flexural (bending) loads, concrete fractures ... rather easily, actually ... concrete failure is not a slow, plastic bending, but a sharp dramatic failure ... the steel reinforcing bars embedded in the concrete is placed there to sustain the bending loads, called 'moment loads', that concrete cannot resist.
  

... what is described in the article above is a 60cm x 60cm section subsiding 5cm ... it sounds as a "punching" failure ... this is not the slow subsiding we are witnessing throughout Thailand ... the article does not describe a smooth flexing, which concrete cannot do, as with pliant materials (wood, metal, plastic, etc.) ... the article describes a concrete slab that cracked, separated and dropped 5cm below the level of the surfaces around it ... nothing about this form of concrete "punching" failure (if that is what this is) is normal ... it is not maintenance related ... it would be a dramatic structural failure.

... but a runway failure of this type should not be misconstrued as the problem ... it is not ... the runway failure as this is a symptom of a much greater problem ... the symptom could be caused by a couple of most likely sources:

• The higher probability is that inferior foundations are the most likely symptom of the problem ... no matter how competently the runway slab is designed and built, it is predicated on having a firm foundation ... a failed foundation almost invariably results in failed structures that sit upon them ... because the compacted substrate, subsoil drainage system and pilings (which I presume they used in a swamp) cannot be 100% tested (only sampled), there is a huge exposure here;
  
• Less likely is an inferior runway slab itself ... slab design is fairly straight-forward ... very well-developed, proved construction technology, materials and design standards ... the key is the foundation.
  

... the greater problem of a runway failure as this, as opposed to the symptoms of the problem, could in my view include the following, in order of likelihood:

• Most likely, is inferior quality construction practices ... not installing materials in conformance to the design... this could be simple gross mismanagement, which I've heard is not so unheard of here in Thailand ('mai pen rai' ... 'do just enough'... 'aww, you tink too mutt') ... or, if a Thai contractor did have larceny in him, relatively few co-conspiritors would have to be recruited to get away with taking inferior short cuts ... this is particularly possible when a great deal of work is done in the cool of the night, as was I believe the case here;
  
• A bit less likely, is inferior construction materials ... low-strength concrete, or low-strength reinforcing steel ... in an environment of corruption and incompetence, substituting inferior construction materials is a distinct possibility ... however, the safety factors applied in the design of structures (to international design standards) are quite forgiving ... if inferior materials were substituted, they would be substituted to massive degrees to cause a failure as this;
  
• Least likely, is inferior design ... engineers in Thailand are personally liable (civilly and criminally) for damages and deaths caused by the failures of structures they design ... to protect themselves, Thai engineers are understandably notorious for overdesigning structures to account for the corrupt building practices indemic in Thailand ... and, as mentioned above, international design standards include significant factors of safety that will forgive a measure of inferior construction practices and materials.
  

... but, going back to the top, if this runway failure is as described in the article (a 'punching' failure), this failure could well be the harbinger of a chronic decay of the runway, now underway ... unlikely that it is an isolated failure, but representative of how the entire runway was constructed.

... open 6 years now, major deficiencies at Suvarnabhumi Airport continue to mount ... these are not the isolated sort of corrections expected at the opening of new projects ... these are deeply flawed, fundamental systems deficiencies reflective of a broader mentality ... that is a concern.

... the Thai government is trying to remedially correct them, which is always inferior to doing them correctly in the first place ... leaky roof ... insufficient air-conditioning ... fire safety violations ... too few bathrooms ... radar and air traffic control system failures ... back-up power system failures ... spalling runway concrete ... insufficiently drained, highly expansive subsoils ... under-designed passenger capacity ... forget the ongoing operational problems, this is just the hardware.

... the world's latest technology, most experienced consultants and best contractors and suppliers were available to Thailand in launching it's greatest public infrastructure achievement to date ... Thailand's front door and calling card to the world is suffering signs of obsolesence ... it is 5-1/2 years old.

... anything anyone needs to know about this nation, doing business or living here, is neatly packaged in the story of the building of Thailand's Suvarnabhumi International Airport ... a remarkable story, truly.

Edited July 7, 2012 by swillowbee

[stormstereo]

It seems Thais wait until things break, like airport runways with sink holes, instead of testing and doing preventative maintenance. Here is how to test runways, take preventative action, before aircraft are damaged. Could someone forward this to AOT?

It ends with "QUESTIONS". I have one: Why the heck was that whole presentation in CAPITAL LETTERS? Made it a lot harder to read and it was probably harder to cram all that text into each page.

[Lingba]

good thing Don Meuang openned again...looks like we all may be headed back there

[DefaultName]

I keep wondering what sort of repair they can do in 15 minutes. A bucket of quick-drying concrete and smooth it over with a trowel?

[Bagwan]

Let us build a F1- circuit!!!!

We have one it go's all the way around the moat. Exiting to watch during songkrahn. Does any one know what Tsongkhapa is? I got that on my spell checker when I checked Songkhran.

You use a spell checker? You deserve to be horse whipped and permanently banned. This is ThaiVisa, remember?

I am not from Barcelona but it may be assumed that I know nothing, on the subject of airport runways and taxiways anyway. However it would be a delicious irony if Mr. T's specially designed and vertically extended control tower, so as to make it one of the wonders of the World, began to sink down into the ground and then virtually disappeared.

When the taxiways were being constructed, well behind schedule of course, a contractor explained to the visiting Minister of Transport that his lorries kept sinking into the ground and had to be dug out, hence the delay. He said that this being because the area was infested with evil spirits. The Minister was reported as saying that he knew that this was true because an evil spirit had just flown right past him. I assume that an army of monks was recruited to drive them away. Only in Thailand - and right up there with the 1000 motor boats.

[Konini]

Dumb question. I'm a geek not an engineer. Thank you for your explanation swillowbee. What would be worst case scenario? Possible bumpy landing or possible disastrous and fatal landing? Also, is it only landing - as in could taxi or take off be a problem? Told you it was a dumb question, but I have no knowledge in this area.

Just curious, it's not going to stop me regularly flying in and out of Swampy.

Yet.

[Moruya]

You can see why Number One didn't want it named after him or his family.

They tend to name some airports after people once they are dead. Charles De Gaulle, Dulles & Ronald Reagan International come to mind.

So maybe in years to come, there may be planes landing at Shinawatra International Airport.

ShIT has a certain ring about it - excuse the pun!

EDIT - having reviewed the rest of the thread - it would appear that I am far from the first to suggest this - apologies!

Edited July 7, 2012 by Moruya

[MEL1]

... a degreed civil engineer here... structural ... don't know it all, but do know a good bit about the subject.

... without inspecting the damages, we can only speculate on causes of the Suvarnabhumi runway failures ... but, this does not sound favorable for the AOT and Thailand's reputation as a nation capable of achieving international standards.

... a few observations ... basics:

• Concrete does not flex well... it is designed to sustain tremendous compression loads, so dropping a fully loaded A380 at 200 knots onto its surface is no problem for properly designed and constructed concrete runways; however,
  
• When subject to significant flexural (bending) loads, concrete fractures ... rather easily, actually ... concrete failure is not a slow, plastic bending, but a sharp dramatic failure ... the steel reinforcing bars embedded in the concrete is placed there to sustain the bending loads, called 'moment loads', that concrete cannot resist.
  

... what is described in the article above is a 60cm x 60cm section subsiding 5cm ... it sounds as a "punching" failure ... this is not the slow subsiding we are witnessing throughout Thailand ... the article does not describe a smooth flexing, which concrete cannot do, as with pliant materials (wood, metal, plastic, etc.) ... the article describes a concrete slab that cracked, separated and dropped 5cm below the level of the surfaces around it ... nothing about this form of concrete "punching" failure (if that is what this is) is normal ... it is not maintenance related ... it would be a dramatic structural failure.

... but a runway failure of this type should not be misconstrued as the problem ... it is not ... the runway failure as this is a symptom of a much greater problem ... the symptom could be caused by a couple of most likely sources:

• The higher probability is that inferior foundations are the most likely symptom of the problem ... no matter how competently the runway slab is designed and built, it is predicated on having a firm foundation ... a failed foundation almost invariably results in failed structures that sit upon them ... because the compacted substrate, subsoil drainage system and pilings (which I presume they used in a swamp) cannot be 100% tested (only sampled), there is a huge exposure here;
  
• Less likely is an inferior runway slab itself ... slab design is fairly straight-forward ... very well-developed, proved construction technology, materials and design standards ... the key is the foundation.
  

... the greater problem of a runway failure as this, as opposed to the symptoms of the problem, could in my view include the following, in order of likelihood:

• Most likely, is inferior quality construction practices ... not installing materials in conformance to the design... this could be simple gross mismanagement, which I've heard is not so unheard of here in Thailand ('mai pen rai' ... 'do just enough'... 'aww, you tink too mutt') ... or, if a Thai contractor did have larceny in him, relatively few co-conspiritors would have to be recruited to get away with taking inferior short cuts ... this is particularly possible when a great deal of work is done in the cool of the night, as was I believe the case here;
  
• A bit less likely, is inferior construction materials ... low-strength concrete, or low-strength reinforcing steel ... in an environment of corruption and incompetence, substituting inferior construction materials is a distinct possibility ... however, the safety factors applied in the design of structures (to international design standards) are quite forgiving ... if inferior materials were substituted, they would be substituted to massive degrees to cause a failure as this;
  
• Least likely, is inferior design ... engineers in Thailand are personally liable (civilly and criminally) for damages and deaths caused by the failures of structures they design ... to protect themselves, Thai engineers are understandably notorious for overdesigning structures to account for the corrupt building practices indemic in Thailand ... and, as mentioned above, international design standards include significant factors of safety that will forgive a measure of inferior construction practices and materials.
  

... but, going back to the top, if this runway failure is as described in the article (a 'punching' failure), this failure could well be the harbinger of a chronic decay of the runway, now underway ... unlikely that it is an isolated failure, but representative of how the entire runway was constructed.

... open 6 years now, major deficiencies at Suvarnabhumi Airport continue to mount ... these are not the isolated sort of corrections expected at the opening of new projects ... these are deeply flawed, fundamental systems deficiencies reflective of a broader mentality ... that is a concern.

... the Thai government is trying to remedially correct them, which is always inferior to doing them correctly in the first place ... leaky roof ... insufficient air-conditioning ... fire safety violations ... too few bathrooms ... radar and air traffic control system failures ... back-up power system failures ... spalling runway concrete ... insufficiently drained, highly expansive subsoils ... under-designed passenger capacity ... forget the ongoing operational problems, this is just the hardware.

... the world's latest technology, most experienced consultants and best contractors and suppliers were available to Thailand in launching it's greatest public infrastructure achievement to date ... Thailand's front door and calling card to the world is suffering signs of obsolesence ... it is 5-1/2 years old.

... anything anyone needs to know about this nation, doing business or living here, is neatly packaged in the story of the building of Thailand's Suvarnabhumi International Airport ... a remarkable story, truly.

As a degreed civil engineer, why have you not gone into detail about subsidence, the causes of it - re building on swamp land, the dispersion of water from the supporting sub-strates (sand and limestone in this case), the causes of air pockets and sub-support ground failure when the water which supports those substrates is dispersed, tapped, drained, and so on as the list goes on.

I was hoping for some asertions from a 'civil' engineer to some of my previous posts and statements, which I sourced from general knowledge, and even quoted an internet source.

Would you care to go into detail about the subsidence happening below the concrete slabs, as I think most don't have a problem with the runway surface construction.

-mel.

[Moruya]

Dumb question. I'm a geek not an engineer. Thank you for your explanation swillowbee. What would be worst case scenario? Possible bumpy landing or possible disastrous and fatal landing? Also, is it only landing - as in could taxi or take off be a problem? Told you it was a dumb question, but I have no knowledge in this area.

Just curious, it's not going to stop me regularly flying in and out of Swampy.

Yet.

I guess we all know what it feels like to hit a 5cm kerb at 5km/h and at 50km/h in a one tonne car

I don't know what the landing weight of a 747, 777 or A380 is - maybe 150 tonnes??

The landing speed must be arount 180 - 200 km/h

My guess is that the plane could take it - however there may be some people out there with a better understanding of the tolerance of such aircraft

[KhunMichael]

That's what I've found on Wikipedia:

On 27 January 2007, however, the Department of Civil Aviation declined to renew the airport's safety certificate, which expired the previous day. The ICAO requires that international airports hold aerodrome safety certificates, but Suvarnabhumi will continue to operate because the ICAO requirement has yet to be adopted as part of Thai law.

My questions now:

Is this still the current status?

Has the ICAO requirement been adopted as part of Thai law?

[apetley]

I keep wondering what sort of repair they can do in 15 minutes. A bucket of quick-drying concrete and smooth it over with a trowel?

Works in our village:-)

Sent from my GT-I9003 using Thaivisa Connect App

[londonthai]

30h delay in "news" reporting - the west runway closed thursday night.

o nation, o mores

[GentlemanJim]

... a degreed civil engineer here... structural ... don't know it all, but do know a good bit about the subject.

... without inspecting the damages, we can only speculate on causes of the Suvarnabhumi runway failures ... but, this does not sound favorable for the AOT and Thailand's reputation as a nation capable of achieving international standards.

... a few observations ... basics:

• Concrete does not flex well... it is designed to sustain tremendous compression loads, so dropping a fully loaded A380 at 200 knots onto its surface is no problem for properly designed and constructed concrete runways; however,
  
• When subject to significant flexural (bending) loads, concrete fractures ... rather easily, actually ... concrete failure is not a slow, plastic bending, but a sharp dramatic failure ... the steel reinforcing bars embedded in the concrete is placed there to sustain the bending loads, called 'moment loads', that concrete cannot resist.
  

... what is described in the article above is a 60cm x 60cm section subsiding 5cm ... it sounds as a "punching" failure ... this is not the slow subsiding we are witnessing throughout Thailand ... the article does not describe a smooth flexing, which concrete cannot do, as with pliant materials (wood, metal, plastic, etc.) ... the article describes a concrete slab that cracked, separated and dropped 5cm below the level of the surfaces around it ... nothing about this form of concrete "punching" failure (if that is what this is) is normal ... it is not maintenance related ... it would be a dramatic structural failure.

... but a runway failure of this type should not be misconstrued as the problem ... it is not ... the runway failure as this is a symptom of a much greater problem ... the symptom could be caused by a couple of most likely sources:

• The higher probability is that inferior foundations are the most likely symptom of the problem ... no matter how competently the runway slab is designed and built, it is predicated on having a firm foundation ... a failed foundation almost invariably results in failed structures that sit upon them ... because the compacted substrate, subsoil drainage system and pilings (which I presume they used in a swamp) cannot be 100% tested (only sampled), there is a huge exposure here;
  
• Less likely is an inferior runway slab itself ... slab design is fairly straight-forward ... very well-developed, proved construction technology, materials and design standards ... the key is the foundation.
  

... the greater problem of a runway failure as this, as opposed to the symptoms of the problem, could in my view include the following, in order of likelihood:

• Most likely, is inferior quality construction practices ... not installing materials in conformance to the design... this could be simple gross mismanagement, which I've heard is not so unheard of here in Thailand ('mai pen rai' ... 'do just enough'... 'aww, you tink too mutt') ... or, if a Thai contractor did have larceny in him, relatively few co-conspiritors would have to be recruited to get away with taking inferior short cuts ... this is particularly possible when a great deal of work is done in the cool of the night, as was I believe the case here;
  
• A bit less likely, is inferior construction materials ... low-strength concrete, or low-strength reinforcing steel ... in an environment of corruption and incompetence, substituting inferior construction materials is a distinct possibility ... however, the safety factors applied in the design of structures (to international design standards) are quite forgiving ... if inferior materials were substituted, they would be substituted to massive degrees to cause a failure as this;
  
• Least likely, is inferior design ... engineers in Thailand are personally liable (civilly and criminally) for damages and deaths caused by the failures of structures they design ... to protect themselves, Thai engineers are understandably notorious for overdesigning structures to account for the corrupt building practices indemic in Thailand ... and, as mentioned above, international design standards include significant factors of safety that will forgive a measure of inferior construction practices and materials.
  

... but, going back to the top, if this runway failure is as described in the article (a 'punching' failure), this failure could well be the harbinger of a chronic decay of the runway, now underway ... unlikely that it is an isolated failure, but representative of how the entire runway was constructed.

... open 6 years now, major deficiencies at Suvarnabhumi Airport continue to mount ... these are not the isolated sort of corrections expected at the opening of new projects ... these are deeply flawed, fundamental systems deficiencies reflective of a broader mentality ... that is a concern.

... the Thai government is trying to remedially correct them, which is always inferior to doing them correctly in the first place ... leaky roof ... insufficient air-conditioning ... fire safety violations ... too few bathrooms ... radar and air traffic control system failures ... back-up power system failures ... spalling runway concrete ... insufficiently drained, highly expansive subsoils ... under-designed passenger capacity ... forget the ongoing operational problems, this is just the hardware.

... the world's latest technology, most experienced consultants and best contractors and suppliers were available to Thailand in launching it's greatest public infrastructure achievement to date ... Thailand's front door and calling card to the world is suffering signs of obsolesence ... it is 5-1/2 years old.

... anything anyone needs to know about this nation, doing business or living here, is neatly packaged in the story of the building of Thailand's Suvarnabhumi International Airport ... a remarkable story, truly.

As a degreed civil engineer, why have you not gone into detail about subsidence, the causes of it - re building on swamp land, the dispersion of water from the supporting sub-strates (sand and limestone in this case), the causes of air pockets and sub-support ground failure when the water which supports those substrates is dispersed, tapped, drained, and so on as the list goes on.

I was hoping for some asertions from a 'civil' engineer to some of my previous posts and statements, which I sourced from general knowledge, and even quoted an internet source.

Would you care to go into detail about the subsidence happening below the concrete slabs, as I think most don't have a problem with the runway surface construction.

-mel.

Mel

Lets be fair, the post by swillowbee is quite awesome and full of excellent information. If he types like me it probably took 25 mins and a cup of coffee. The additional info you want would be great but give the guy a chance, only so many hours in the day eh!

I like you understand that the geology is the issue, What swampy does not want is very wet rainy seasons followed by prolonged periods of heat and drought. The subsequent fall in the level of the water table and the accompanied 'shrinkage' are the conditions that could see gaping holes appear, but in the nature that swillowbee describes, sudden, violent and dramatic, and enough to ruin your day if you are in the stages of a take off run or landing.

To give you an idea of how dramatic and sudden these things occur when the wrong geology is in place, check out the mother below that opened in Guatemala after a tropical storm!!! Photoshop not involved!

[cowslip]

<p>A good way to get an idea of the extent of inherent corruption in a nation is to look at the roads. If new or recent roads get damaged quickly or subside, it is usually because the people responsible for laying the foundations - hardcore etc. -  have spent the money on something else - holidays, new cars etc - extending this practice to the national airport is surely taking the practice to new extremes?</p>

<div id="myEventWatcherDiv" style="display:none;"> </div>

Edited July 7, 2012 by cowslip

[dude007]

I told it before: it's not the bad compaction of the reclaimed land; it's the sub-standard quality of the sand (too silty) that causes the problem. The drainage capacity of this sand is too low and compaction pressure by heavy sudden loads (be it a compactor or an aircraft) is taken by the water particles, not the soil grains, with all the consequences.

May I suggets that the certificates of soil-aptness be checked (which were issued during the Thaksin I and II government by crooked soil laboratories working for TRT nominees) be thoroughly checked and these particular "substandard" soils be identified where they were used for reclaiming the swamp with 4 meters... (something which unfortunately is no longer possible). Remarkable and coincidently the sand was coming from borrow pits, all belonging to TRT MP's and Thaksin cronies. This "sandy soil" was bought at an incredible price... And that's why this Suvarnabhumi airport has costed three times its normal price. No one can put the link anymore with the actual problems in the runway but these problems will continue to exist for many more years to come. This will NEVER be a good runway if the 4 meters reclaimed sand was sub-standard, which becomes more an more clear now. Corruption and greed, the two most known characteristics of the Thaksin era... are now costing its toll. And this man still runs free...

[dude007]

... a degreed civil engineer here... structural ... don't know it all, but do know a good bit about the subject.

... without inspecting the damages, we can only speculate on causes of the Suvarnabhumi runway failures ... but, this does not sound favorable for the AOT and Thailand's reputation as a nation capable of achieving international standards.

... a few observations ... basics:

• Concrete does not flex well... it is designed to sustain tremendous compression loads, so dropping a fully loaded A380 at 200 knots onto its surface is no problem for properly designed and constructed concrete runways; however,
  
• When subject to significant flexural (bending) loads, concrete fractures ... rather easily, actually ... concrete failure is not a slow, plastic bending, but a sharp dramatic failure ... the steel reinforcing bars embedded in the concrete is placed there to sustain the bending loads, called 'moment loads', that concrete cannot resist.
  

... what is described in the article above is a 60cm x 60cm section subsiding 5cm ... it sounds as a "punching" failure ... this is not the slow subsiding we are witnessing throughout Thailand ... the article does not describe a smooth flexing, which concrete cannot do, as with pliant materials (wood, metal, plastic, etc.) ... the article describes a concrete slab that cracked, separated and dropped 5cm below the level of the surfaces around it ... nothing about this form of concrete "punching" failure (if that is what this is) is normal ... it is not maintenance related ... it would be a dramatic structural failure.

... but a runway failure of this type should not be misconstrued as the problem ... it is not ... the runway failure as this is a symptom of a much greater problem ... the symptom could be caused by a couple of most likely sources:

• The higher probability is that inferior foundations are the most likely symptom of the problem ... no matter how competently the runway slab is designed and built, it is predicated on having a firm foundation ... a failed foundation almost invariably results in failed structures that sit upon them ... because the compacted substrate, subsoil drainage system and pilings (which I presume they used in a swamp) cannot be 100% tested (only sampled), there is a huge exposure here;
  
• Less likely is an inferior runway slab itself ... slab design is fairly straight-forward ... very well-developed, proved construction technology, materials and design standards ... the key is the foundation.
  

... the greater problem of a runway failure as this, as opposed to the symptoms of the problem, could in my view include the following, in order of likelihood:

• Most likely, is inferior quality construction practices ... not installing materials in conformance to the design... this could be simple gross mismanagement, which I've heard is not so unheard of here in Thailand ('mai pen rai' ... 'do just enough'... 'aww, you tink too mutt') ... or, if a Thai contractor did have larceny in him, relatively few co-conspiritors would have to be recruited to get away with taking inferior short cuts ... this is particularly possible when a great deal of work is done in the cool of the night, as was I believe the case here;
  
• A bit less likely, is inferior construction materials ... low-strength concrete, or low-strength reinforcing steel ... in an environment of corruption and incompetence, substituting inferior construction materials is a distinct possibility ... however, the safety factors applied in the design of structures (to international design standards) are quite forgiving ... if inferior materials were substituted, they would be substituted to massive degrees to cause a failure as this;
  
• Least likely, is inferior design ... engineers in Thailand are personally liable (civilly and criminally) for damages and deaths caused by the failures of structures they design ... to protect themselves, Thai engineers are understandably notorious for overdesigning structures to account for the corrupt building practices indemic in Thailand ... and, as mentioned above, international design standards include significant factors of safety that will forgive a measure of inferior construction practices and materials.
  

... but, going back to the top, if this runway failure is as described in the article (a 'punching' failure), this failure could well be the harbinger of a chronic decay of the runway, now underway ... unlikely that it is an isolated failure, but representative of how the entire runway was constructed.

... open 6 years now, major deficiencies at Suvarnabhumi Airport continue to mount ... these are not the isolated sort of corrections expected at the opening of new projects ... these are deeply flawed, fundamental systems deficiencies reflective of a broader mentality ... that is a concern.

... the Thai government is trying to remedially correct them, which is always inferior to doing them correctly in the first place ... leaky roof ... insufficient air-conditioning ... fire safety violations ... too few bathrooms ... radar and air traffic control system failures ... back-up power system failures ... spalling runway concrete ... insufficiently drained, highly expansive subsoils ... under-designed passenger capacity ... forget the ongoing operational problems, this is just the hardware.

... the world's latest technology, most experienced consultants and best contractors and suppliers were available to Thailand in launching it's greatest public infrastructure achievement to date ... Thailand's front door and calling card to the world is suffering signs of obsolesence ... it is 5-1/2 years old.

... anything anyone needs to know about this nation, doing business or living here, is neatly packaged in the story of the building of Thailand's Suvarnabhumi International Airport ... a remarkable story, truly.

Swillowbee, dear colleague civil structural engineer, I fully agree with your analsyis, athough I know that substandard sand from borrow pits (belonging to TRT PM's) have been used for reclamation at a very high price, certified by crooked soil laboratories, which do no longer exist anymore...

[MEL1]

... a degreed civil engineer here... structural ... don't know it all, but do know a good bit about the subject.

... without inspecting the damages, we can only speculate on causes of the Suvarnabhumi runway failures ... but, this does not sound favorable for the AOT and Thailand's reputation as a nation capable of achieving international standards.

... a few observations ... basics:

• Concrete does not flex well... it is designed to sustain tremendous compression loads, so dropping a fully loaded A380 at 200 knots onto its surface is no problem for properly designed and constructed concrete runways; however,
  
• When subject to significant flexural (bending) loads, concrete fractures ... rather easily, actually ... concrete failure is not a slow, plastic bending, but a sharp dramatic failure ... the steel reinforcing bars embedded in the concrete is placed there to sustain the bending loads, called 'moment loads', that concrete cannot resist.
  

... what is described in the article above is a 60cm x 60cm section subsiding 5cm ... it sounds as a "punching" failure ... this is not the slow subsiding we are witnessing throughout Thailand ... the article does not describe a smooth flexing, which concrete cannot do, as with pliant materials (wood, metal, plastic, etc.) ... the article describes a concrete slab that cracked, separated and dropped 5cm below the level of the surfaces around it ... nothing about this form of concrete "punching" failure (if that is what this is) is normal ... it is not maintenance related ... it would be a dramatic structural failure.

... but a runway failure of this type should not be misconstrued as the problem ... it is not ... the runway failure as this is a symptom of a much greater problem ... the symptom could be caused by a couple of most likely sources:

• The higher probability is that inferior foundations are the most likely symptom of the problem ... no matter how competently the runway slab is designed and built, it is predicated on having a firm foundation ... a failed foundation almost invariably results in failed structures that sit upon them ... because the compacted substrate, subsoil drainage system and pilings (which I presume they used in a swamp) cannot be 100% tested (only sampled), there is a huge exposure here;
  
• Less likely is an inferior runway slab itself ... slab design is fairly straight-forward ... very well-developed, proved construction technology, materials and design standards ... the key is the foundation.
  

... the greater problem of a runway failure as this, as opposed to the symptoms of the problem, could in my view include the following, in order of likelihood:

• Most likely, is inferior quality construction practices ... not installing materials in conformance to the design... this could be simple gross mismanagement, which I've heard is not so unheard of here in Thailand ('mai pen rai' ... 'do just enough'... 'aww, you tink too mutt') ... or, if a Thai contractor did have larceny in him, relatively few co-conspiritors would have to be recruited to get away with taking inferior short cuts ... this is particularly possible when a great deal of work is done in the cool of the night, as was I believe the case here;
  
• A bit less likely, is inferior construction materials ... low-strength concrete, or low-strength reinforcing steel ... in an environment of corruption and incompetence, substituting inferior construction materials is a distinct possibility ... however, the safety factors applied in the design of structures (to international design standards) are quite forgiving ... if inferior materials were substituted, they would be substituted to massive degrees to cause a failure as this;
  
• Least likely, is inferior design ... engineers in Thailand are personally liable (civilly and criminally) for damages and deaths caused by the failures of structures they design ... to protect themselves, Thai engineers are understandably notorious for overdesigning structures to account for the corrupt building practices indemic in Thailand ... and, as mentioned above, international design standards include significant factors of safety that will forgive a measure of inferior construction practices and materials.
  

... but, going back to the top, if this runway failure is as described in the article (a 'punching' failure), this failure could well be the harbinger of a chronic decay of the runway, now underway ... unlikely that it is an isolated failure, but representative of how the entire runway was constructed.

... open 6 years now, major deficiencies at Suvarnabhumi Airport continue to mount ... these are not the isolated sort of corrections expected at the opening of new projects ... these are deeply flawed, fundamental systems deficiencies reflective of a broader mentality ... that is a concern.

... the Thai government is trying to remedially correct them, which is always inferior to doing them correctly in the first place ... leaky roof ... insufficient air-conditioning ... fire safety violations ... too few bathrooms ... radar and air traffic control system failures ... back-up power system failures ... spalling runway concrete ... insufficiently drained, highly expansive subsoils ... under-designed passenger capacity ... forget the ongoing operational problems, this is just the hardware.

... the world's latest technology, most experienced consultants and best contractors and suppliers were available to Thailand in launching it's greatest public infrastructure achievement to date ... Thailand's front door and calling card to the world is suffering signs of obsolesence ... it is 5-1/2 years old.

... anything anyone needs to know about this nation, doing business or living here, is neatly packaged in the story of the building of Thailand's Suvarnabhumi International Airport ... a remarkable story, truly.

As a degreed civil engineer, why have you not gone into detail about subsidence, the causes of it - re building on swamp land, the dispersion of water from the supporting sub-strates (sand and limestone in this case), the causes of air pockets and sub-support ground failure when the water which supports those substrates is dispersed, tapped, drained, and so on as the list goes on.

I was hoping for some asertions from a 'civil' engineer to some of my previous posts and statements, which I sourced from general knowledge, and even quoted an internet source.

Would you care to go into detail about the subsidence happening below the concrete slabs, as I think most don't have a problem with the runway surface construction.

-mel.

Mel

Lets be fair, the post by swillowbee is quite awesome and full of excellent information. If he types like me it probably took 25 mins and a cup of coffee. The additional info you want would be great but give the guy a chance, only so many hours in the day eh!

I like you understand that the geology is the issue, What swampy does not want is very wet rainy seasons followed by prolonged periods of heat and drought. The subsequent fall in the level of the water table and the accompanied 'shrinkage' are the conditions that could see gaping holes appear, but in the nature that swillowbee describes, sudden, violent and dramatic, and enough to ruin your day if you are in the stages of a take off run or landing.

To give you an idea of how dramatic and sudden these things occur when the wrong geology is in place, check out the mother below that opened in Guatemala after a tropical storm!!! Photoshop not involved!

It was exactly this kind of extreme scenario and those in Florida that I wan't referring to though mate.

It's the constant smaller troughs that develop all over the place, roads sinking in BKK and everywhere as a result of poor substructure laying, and a non-undertsanding of sedimentary requirements below, in the first place, that's the worry. For this to be now happening below runways..... well... I have no words really to explain the catostrophes awating, nor the ignorance of the authorities to just cover them up with blind blankets of what they believe is crack filling as the ultimate answer.

Oh! and Edit: No disrespect to you swillowbee, I was looking for further evidence of the ground subsidence and not surface failure, from a qualified person.... thaz all folks!

Edited July 7, 2012 by MEL1

[animatic]

Its obviously not easy with the type of ground and flooding too.

But I suspect that fund mismanagement and corruption by Thaksin is the reason we have these problems in such frequency and severity. Its sort of ironic and also a sad indictment of anti-DP rhetoric, that people are so quick to talk-up the short 'airport seige' by PAD as being a huge blow to the airport functioning as a profitable entity, and the siege's impact on tourist confidence, when in fact the protesters were there for eight days, insignificant compared to all the closure and delays for reparations caused by mismanagement during construction, and PAD were protesting to remove Thaksin's corrupt regime, the very same regime who had robbed money from the construction of the same airport and led to it being an ongoing safety concern years later.

Dangerous runways discourages tourism far worse than eight days peaceful sit-down protest does. It also had over 60 structural faults when it was first opened over a year late, coupled with the flawed runways it doesn't inspire confidence at all.

If it is true that nepotism rather than construction safety-standards determined who Thaksin gave the contracts to, and the money was indeed spent on things other than the airport, then this should be investigated by the current PM, his sister.

Though I would posit it was far from just Thaksins administration that was involved in this debacle. He just applied the finally under-spec screws to the façade covering the sub-standard reality, and let all believe the frosting was an actual cake.

[khaowong1]

The airport should be closed now, & a team of overseas specialists should be brought in to thoroughly investigate the true extent of the the problem.

If not all the major airlines should boycott the airport .

Sure, like that's really going to happen.

[khaowong1]

That's what I've found on Wikipedia:

On 27 January 2007, however, the Department of Civil Aviation declined to renew the airport's safety certificate, which expired the previous day. The ICAO requires that international airports hold aerodrome safety certificates, but Suvarnabhumi will continue to operate because the ICAO requirement has yet to be adopted as part of Thai law.

My questions now:

Is this still the current status?

Has the ICAO requirement been adopted as part of Thai law?

Yeah, right.

[Babcock]

So much rubbish posted in response to this story. The problem of cracking and stripping (where the bitumen comes away from the concrete below) is common. The issue here is the maintenance schedule. The sky is not falling. It is not the end of the world. Once the maintenance schedule is sorted everything will be fine. It is normal to have runways closed for resurfacing and repair work. I believe Sydney airport had a runway closed for nearly a year with maintenance and repair works taking place.

My understanding from posts from the other paper that they have found an area 60cm square sunk 5 cm.

I mean if that's true this story's a joke.

[GentlemanJim]

Mel

Lets be fair, the post by swillowbee is quite awesome and full of excellent information. If he types like me it probably took 25 mins and a cup of coffee. The additional info you want would be great but give the guy a chance, only so many hours in the day eh!

I like you understand that the geology is the issue, What swampy does not want is very wet rainy seasons followed by prolonged periods of heat and drought. The subsequent fall in the level of the water table and the accompanied 'shrinkage' are the conditions that could see gaping holes appear, but in the nature that swillowbee describes, sudden, violent and dramatic, and enough to ruin your day if you are in the stages of a take off run or landing.

To give you an idea of how dramatic and sudden these things occur when the wrong geology is in place, check out the mother below that opened in Guatemala after a tropical storm!!! Photoshop not involved!

It was exactly this kind of extreme scenario and those in Florida that I wan't referring to though mate.

It's the constant smaller troughs that develop all over the place, roads sinking in BKK and everywhere as a result of poor substructure laying, and a non-undertsanding of sedimentary requirements below, in the first place, that's the worry. For this to be now happening below runways..... well... I have no words really to explain the catostrophes awating, nor the ignorance of the authorities to just cover them up with blind blankets of what they believe is crack filling as the ultimate answer.

Oh! and Edit: No disrespect to you swillowbee, I was looking for further evidence of the ground subsidence and not surface failure, from a qualified person.... thaz all folks!

Mel

Thanks. Sorry, when I posted the picture of the sinkhole in Guatemala I did not mean to imply that that kind of thing could happen at swampy. It was just an amazing example of just how bad a sinkhole can get. I agree around BKK it is the many many examples of smaller ones that are worrying, and it would only take a relatively small sinkhole at swampy to rip the undercarraige off an aircraft. When you see them appearing all around the city it makes you wonder what could happen, say with the main supports for the BTS etc etc.