Central May Be About To Collapse

[Phil Conners]

BM LennyW posted the following two images from Centrals carpark in another tread where it unfortunately got buried in a long discussion about other things. I though it was important to give everybody a chance to look at the pictures and judge for themselves.

Several comments were made: Some people report they have felt the building "shuddering", others, presumably with engineering experience suggest that adding these metal things to the carrying concrete pillars risk damaging the structural integrity of the pillars.

I don't know but I think it is very worrying to think about what may happen if just one such pillar gives in for the weight on top - 6 floors of mall + another 8 or so of a hotel on top of it....

[Humphrey Bear]

I haven't looked at this one, but a cautionaryy tale :

Teheran's Mehrabad Airport was supervised by consultant Brian Colquhoun

After completion extra air conditioning was added. In order to put in the ductwork the supporting columns were chipped a little (!!!)

After installing the air-conditioning the authorities decided to add a restaurant - on top of the existing building.

All without knowledge or approval of the BC teheran rep.

Then came the heavy winter snowfall - and the whole dam_n thing collapsed.

Result - a spell in jail for the Brian Colquhoon rep.

I left Iran at about that time and don't know the end of the story.

[Apecks]

BM LennyW posted the following two images from Centrals carpark in another tread where it unfortunately got buried in a long discussion about other things. I though it was important to give everybody a chance to look at the pictures and judge for themselves.

Several comments were made: Some people report they have felt the building "shuddering", others, presumably with engineering experience suggest that adding these metal things to the carrying concrete pillars risk damaging the structural integrity of the pillars.

I don't know but I think it is very worrying to think about what may happen if just one such pillar gives in for the weight on top - 6 floors of mall + another 8 or so of a hotel on top of it....

Looks like some body 'forgot' the rebar

[Soutpeel]

BM LennyW posted the following two images from Centrals carpark in another tread where it unfortunately got buried in a long discussion about other things. I though it was important to give everybody a chance to look at the pictures and judge for themselves.

Several comments were made: Some people report they have felt the building "shuddering", others, presumably with engineering experience suggest that adding these metal things to the carrying concrete pillars risk damaging the structural integrity of the pillars.

I don't know but I think it is very worrying to think about what may happen if just one such pillar gives in for the weight on top - 6 floors of mall + another 8 or so of a hotel on top of it....

Looks like some body 'forgot' the rebar

Dont think I would go that far, inadequate rebar perhaps, if no re-bar, the place would have come down all ready.

Per my previous posting of the opinion the structual sections are a retro-fit to fix an existing problem, how severe, anybodys guess, suppose if anyone has got time on their hands go and count how many columns have these structual sections are installed if all over, then suspect a serious problem..

[MJo]

These supports are not there for the column and generally should not compromise the column as there is only few anchor bolts. Can not see from the pic but the bolts might even go thru the column with grouting. Naturally this means that they have left the rebars intact (usually located only in the corners).

There additional brackets are simply to prevent the column "going straight thru" the floor slab, i was structural designer in my previous life but can not remember the corret term in english now... Basicly to add contact area that transfers the load from the concrete floor slab to the column to prevent the slab breaking (column punching thru the slab) and the column going thru it. This method is very common in concrete columns that are "mushroom" shaped in the top for the same reason. Here it seems that designer forget it or the contractor forget to cast them with the columns...

In any case quite bad mistake either way, if it was the designer his licence should be questioned or revoked and if it was the contractor then he should be made to pay and reorganize his site management and supervisors.

[Soutpeel]

These supports are not there for the column and generally should not compromise the column as there is only few anchor bolts. Can not see from the pic but the bolts might even go thru the column with grouting. Naturally this means that they have left the rebars intact (usually located only in the corners).

There additional brackets are simply to prevent the column "going straight thru" the floor slab, i was structural designer in my previous life but can not remember the corret term in english now... Basicly to add contact area that transfers the load from the concrete floor slab to the column to prevent the slab breaking (column punching thru the slab) and the column going thru it. This method is very common in concrete columns that are "mushroom" shaped in the top for the same reason. Here it seems that designer forget it or the contractor forget to cast them with the columns...

In any case quite bad mistake either way, if it was the designer his licence should be questioned or revoked and if it was the contractor then he should be made to pay and reorganize his site management and supervisors.

Agreed, my worry would be what else have they forgot.. ....a very big oversight on a structual engineers part not to design adequate bearing for slab or complete lack of supervision on the "clients" part.

Re you last paragraph, we are in Thailand, so a few brown envelopes will solve everything..

[deprogrammed]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

[Soutpeel]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

You been reading Wikipedia again..

[deprogrammed]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

You been reading Wikipedia again..

25 years - Construction Engineer (man and boy).

Edited June 6, 2009 by deprogrammed

[Soutpeel]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

You been reading Wikipedia again..

25 years - Constuction Engineer (man and boy).

....With your 25 years in the business, in your opinion does it appear that the builders have f*kced up then..??

Edited June 6, 2009 by Soutpeel

[LennyW]

I guess it is going to be difficult to ever get accurate justification for these "extras", difficult to know how many there are - are they fitted all over the building and hidden by suspended ceilings etc.??, or only in a specific "problem" area??

It sure is not normal anyway, all you condo dwellers here take a look around your buildings, new or old, and i doubt if you will see such add on's!!

Not that long ago since there was a collapse during construction in Pratumnak soi 6........

From the last thread some members have passed on the pics and limited info to engineering types, but no real "concrete" replies yet as it seems too little info to go on for the experts.

[Mobi]

I don't know but I think it is very worrying to think about what may happen if just one such pillar gives in for the weight on top - 6 floors of mall + another 8 or so of a hotel on top of it....

Good idea Phil.

As I posted in the other thread, I have sent copies of these pics and some comments to the Bangkok Post, and am still awaiting their action - if any

[Soutpeel]

It sure is not normal anyway,

You are right, its not normal to do something like this

[ballbreaker]

These supports are not there for the column and generally should not compromise the column as there is only few anchor bolts. Can not see from the pic but the bolts might even go thru the column with grouting. Naturally this means that they have left the rebars intact (usually located only in the corners).

There additional brackets are simply to prevent the column "going straight thru" the floor slab, i was structural designer in my previous life but can not remember the corret term in english now... Basicly to add contact area that transfers the load from the concrete floor slab to the column to prevent the slab breaking (column punching thru the slab) and the column going thru it. This method is very common in concrete columns that are "mushroom" shaped in the top for the same reason. Here it seems that designer forget it or the contractor forget to cast them with the columns...

In any case quite bad mistake either way, if it was the designer his licence should be questioned or revoked and if it was the contractor then he should be made to pay and reorganize his site management and supervisors.

I tend to agree with MJo statements concerning reasons for added steel brackets.

Some may remember the Seoul department store that collapsed 10-15 years ago. It was built using flat slab construction (columns support the floor without use of any beams) because of the added weight from a new floor and air cons on its roof the columns punched through the floor causing the building to collapse. I think they found not enough rebar was used to attach floor to columns for the amount of weight added.

[deprogrammed]

I don't know but I think it is very worrying to think about what may happen if just one such pillar gives in for the weight on top - 6 floors of mall + another 8 or so of a hotel on top of it....

Good idea Phil.

As I posted in the other thread, I have sent copies of these pics and some comments to the Bangkok Post, and am still awaiting their action - if any

Unlikely - considering a previous BKK Editor was forced to resign following negative press given to a very large project - think airplanes!

[PattayaParent]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

You been reading Wikipedia again..

25 years - Construction Engineer (man and boy).

There's so many discerpancies in your explanation I doubt that very much.

Edited June 6, 2009 by PattayaParent

[IanForbes]

Unlikely - considering a previous BKK Editor was forced to resign following negative press given to a very large project - think airplanes!

Yah, and we all know how that turned out. The first couple of my visits were positive, but after that I could never get a quick flight again. I always had to book several days in advance. I never used to have that problem in Don Muang and I always got a flight to Chiang Mai within 2 hours of booking.

[Mobi]

I don't know but I think it is very worrying to think about what may happen if just one such pillar gives in for the weight on top - 6 floors of mall + another 8 or so of a hotel on top of it....

Good idea Phil.

As I posted in the other thread, I have sent copies of these pics and some comments to the Bangkok Post, and am still awaiting their action - if any

Unlikely - considering a previous BKK Editor was forced to resign following negative press given to a very large project - think airplanes!

That was Thaksin inspired. The whole country was in fear and trembling of his power and untold billions.

Things are a bit better now.

There is nothing to prevent an investigative journalist from doing a bit of research and see what he comes up with. If there is a grain of truth to our concerns, a carefully worded story could stay well clear of libel /slander laws.

Just look how they report the bus leasing scandal. The whole world knows it is a major corruption scam on the part of the Dems coalition partner, but no-one is actually saying it in the press.

Even the Bangkok Post can't cover up what may turn out to be a major disaster, and if they did, I doubt they could live it down. They have been advised, (I emailed the Editor in Chief, and the News Editor), so up to them.

If nothing appears soon, I will do the same to the Nation.

Edited June 6, 2009 by Mobi

[MJo]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

You been reading Wikipedia again..

25 years - Construction Engineer (man and boy).

There's so many discerpancies in your explanation I doubt that very much.

Well he's correct as slump test should be done to each batch of concrete before it is poured. It gives some info regarding the mix.

What is also standard practise globally (and also in Thailand) is to take test cubes from the concrete used in load bearing structures and test them in a lab say 7, 14 and 28 days to confirm the concrete strenght is as per specs.

For "savings" the most costly material is the rebar, then cement. So contractors tend to save on rebar and concrete mix plants on cement. However nowdays there is rebar inspections even in thailand just before the pour and also the test cubes to check the mix coming out from a plant. So not that much opportunities to cheat, at least in a project like central. Also what i see here in Bangkok is that bigger condo etc sites look very organized and "modern". Methods and materials used are the same as you see in sites in europe. Actually better here than southern europe. Well that's my opinion just looking at the sites, not working on them here on Thailand. Maybe some in biz here in Thailand can give more professional opinion.

Regarding structural design, it is common practise to design the structures so that what ever reason brings one column down, the structure as a whole will stay up. You can consider it so that if one column is removed, the others around it has extra strenght calculated in so that they will not fail. Then as was the case in Korea, if the whole roof slab or one floor comes down it will take down the rest of the floors as well. Same happened in 9/11, just bigger scale. The reason in korea was indeed vibrations from additional aircon units broke the roof slab and the columns "punctured" the slab.

Anyways there is always a risk that someone is cutting corners. It happens time to time here in Thailand as it still happening sometimes in the west.

[wpcoe]

Another potentially lethal design flaw: The main exit doors on the ground floor leading to the beach side open toward the *inside.* In the case of an emergency stampede, the doors should open *outward.*

[deprogrammed]

The most expensive commodity in such buildings is concrete. To test the potential strength and integrity of the finsihed product, a simple 'slump test' is carried out - at agreed stages during constuction.

Slump test is very simple: eg. a 10 inch peice of plastic pipe is filled with the wet concrete mix and then the pipe pulled from the mix. The amount of slump in the concrete is measured. A one inch slump (depression) for example may be acceptable a 2 inch slump not.

The material - wet concrete - should also be weighed by voulume to give density.

If the pre specified density (specific gravity) and slump are below spec. then the resulting concrete will be honeycombe in structure and lack the required density/strength.

Inspectors (clerk of works) who insist of such measures risk being shot. Enjoy your shopping

You been reading Wikipedia again..

25 years - Construction Engineer (man and boy).

There's so many discerpancies in your explanation I doubt that very much.

When I say man and boy, well I really mean boy - you know leggo

[NanLaew]

It sure is not normal anyway,

You are right, its not normal to do something like this

OK, just because you happen to have had your attention drawn to these steel plates in the parking garage of the local mall, you come out and say it's not normal? How about the thousands of hidden supports and beams in all the multi-storey buildings you have been inside elsewhere in the world? Just because you haven't had your attention drawn to them before (because without the pictures, you would still be blissfully ignorant) does not mean that this is a rare or bad construction practice.

Anyway, I note that some still chose to go head-to-head with construction engineers more experienced and learned commentaries. Keep sounding off and I am sure they will find enough 'wiki-experts' will flock to your cause... whatever it may be. Maybe they seek some morbid satisfaction from 'I told you so' when buildings collapse?

Why the OP wanted to reinvent this 'Bob the Builder says' thread in the first place is a bit beyond me. The first one took a few pages before it got into a pissing contest between the usual suspects. This one is crashing & burning even faster.

[Mobi]

OK, just because you happen to have had your attention drawn to these steel plates in the parking garage of the local mall, you come out and say it's not normal? How about the thousands of hidden supports and beams in all the multi-storey buildings you have been inside elsewhere in the world? Just because you haven't had your attention drawn to them before (because without the pictures, you would still be blissfully ignorant) does not mean that this is a rare or bad construction practice.

Anyway, I note that some still chose to go head-to-head with construction engineers more experienced and learned commentaries. Keep sounding off and I am sure they will find enough 'wiki-experts' will flock to your cause... whatever it may be. Maybe they seek some morbid satisfaction from 'I told you so' when buildings collapse?

Why the OP wanted to reinvent this 'Bob the Builder says' thread in the first place is a bit beyond me. The first one took a few pages before it got into a pissing contest between the usual suspects. This one is crashing & burning even faster.

You are almost certainly correct.

But isn't it better to be safe than sorry?

Personally, I couldn't even construct a Lego building, let alone understand the mysteries of a major construction, project - stresses and the like.

But I do know Thailand, and I do know that anything can, and does happen in this fair land.

I am more concerned about the so-called "shudders", if they are true, than the flanges in the pics, and I for one will stay well away from that building until I learn that someone suitably qualified has given it a clean bill of health.

[crudy21]

Im no construction expert but i do know one thing........ If im ever in there and there is a heavy snowfall, i'll be first one out of the doors!

[NanLaew]

^ At last! An undebatably qualified, well-reasoned and incontestable post on the subject!

[crudy21]

^ At last! An undebatably qualified, well-reasoned and incontestable post on the subject!

No probs dude, if you need any more assistance, im at your call!

[tropo]

It sure is not normal anyway, all you condo dwellers here take a look around your buildings, new or old, and i doubt if you will see such add on's!!

The absence of extra supports in other buildings in Pattaya doesn't mean they are not necessary. Your comment proves nothing at all.

[tropo]

Some may remember the Seoul department store that collapsed 10-15 years ago. It was built using flat slab construction (columns support the floor without use of any beams) because of the added weight from a new floor and air cons on its roof the columns punched through the floor causing the building to collapse. I think they found not enough rebar was used to attach floor to columns for the amount of weight added.

They moved the aircons across the roof by dragging them. This caused damage on the roof which started the collapse.

[LennyW]

It sure is not normal anyway, all you condo dwellers here take a look around your buildings, new or old, and i doubt if you will see such add on's!!

The absence of extra supports in other buildings in Pattaya doesn't mean they are not necessary. Your comment proves nothing at all.

Not trying to prove anything, simply making a comparison.

[Texpat]

The most important consideration has been completely overlooked -- was the building blessed by a busload of monks prior to its opening?