Skyscraper as tall as 1km: Innovative concept from a Bangladeshi engineer

[Bilal9]

Shariful Hasan

Thu Aug 26, 2021 12:00 AM

It may surprise many to know that in the global race to build the tallest skyscrapers, two Bangladeshis have made towering contributions.

Bangladeshi structural engineer and architect, Fazlur Rahman Khan, introduced an important structural system in the 1960s that made the construction of 140-storied buildings possible.

Following in the footsteps of Khan, now another Bangladeshi engineer, Feroz Alam, has come up with a structural concept that would allow for the construction of a 264-storied structure or a skyscraper as tall as one kilometer.

Alam's book "Parallel Shear Walls (PSW)-An Innovative Concept on Mega tall Buildings" published in 2016 has already captivated the structural engineering world. His book ranked 26 out of the 100 structural engineering publications of all times, according to Bookauthority.

It is also ranked 60th among the 100 best-selling books on structural engineering.

I have shown in my structural concept that it is possible to build a 3,262 feet high (one kilometer) skyscraper. At present, if you want to build a building beyond the 20th floor, you have to pay attention to issues related to wind and earthquakes. This requires some additional structural methods that cost a lot of money. But in my structural concept, these are not necessary.

I have shown in my structural concept that it is possible to build a 3,262 feet high (one kilometer) skyscraper. At present, if you want to build a building beyond the 20th floor, you have to pay attention to issues related to wind and earthquakes. This requires some additional structural methods that cost a lot of money. But in my structural concept, these are not necessary.
Due to the growing demand, Alam's book has been published in nine languages -- English, French, German, Italian, Spanish, Dutch, Polish, Portuguese, and Russian.

The novelty of Alam's invented concept is the use of "parallel shear walls" instead of "columns in buildings".

While the column transfers vertical load from top to the bottom, shear wall -- a special type of concrete wall -- can resist horizontal force in a building due to its sheer strength.

"I have shown in my structural concept that it is possible to build a 3,262 feet high (one kilometer) skyscraper. At present, if you want to build a building beyond the 20th floor, you have to pay attention to issues related to wind and earthquakes. This requires some additional structural methods that cost a lot of money. But in my structural concept, these are not necessary," Feroz Alam told The Daily Star recently.

He also said that his concept does not require a vanity height, while referring to Burj Al Khalifa, the world's tallest skyscraper in Dubai.

Standing at 2,619 feet tall, Burj Al Khalifa has up to 2,060 feet for commercial and personal use. The remaining 659 feet is called the vanity height or beauty enhancement part.

Alam, who worked as a structural engineer in different countries of the Middle East for more than 20 years, came to the global spotlight when his innovative concept "Parallel Shear Walls" was published in the American Journal of Civil Engineering in 2016.

The University of Illinois invited Alam to give a presentation on the new concept. Afterwards, a German publishing house, "Scholars Press" approached him to write a book on his groundbreaking work.

Feroz's book was completed in 2016 and a second edition was published in February 2021 with more details. Both editions have been translated into nine languages. His book is also available on Amazon and other European websites.

"Many countries around the world have been researching this structural concept since the book was published. Multi-storied buildings have already been built in Qatar and India using this concept. Bangladesh, a country with a growing population, can also use it to construct buildings from 30 stories and above. This will save both land space and cost," Alam said.

Engr Anwar Hossain Akon, former chairman of the Institute of Engineers, Bangladesh (IEB) Qatar Chapter, told The Daily Star, "The construction of a one-kilometer-tall building was just a fantasy. But now it is a matter of pride for us that a Bangladeshi has shown the way for 3,282 feet high buildings."

Dr Golam Mostafa, former president of the Engineers' Association (IEB) and current chairman of Dhaka Wasa, said, "Feroz Alam's book is not only on the list of the best structural engineering books of all time but it is also being read by engineers in different countries."

"It is a breakthrough concept in the construction of multi-storey buildings. However, it is sad to say that he has not yet gotten proper recognition in the country."

Dr Shafiul Bari, a professor of civil engineering at BUET, opined, "Alam's innovative parallel shear walls theory will also be useful to the construction of 20-50 storied buildings."

Born on June 29, 1964, in Rangpur in a family dominated by physicians, Alam however had a keen interest in mathematics from his childhood. He has graduated from the Institute of Engineers (IEB) with a degree in civil engineering in 1991 and MSc in civil engineering from USA in 2013.
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These are pre-cast shear walls manufactured and put to use in US buildings.

 

[Tamiyah]

Do u have any more graphical representation of his idea?

 

[Michael Corleone]

Do u have any more graphical representation of his idea?

tell me that as a kid you didn’t try make structure with your book opened at right angles because I did.
man this is so simple yet genius.
one dude goes to take out cigarette from his pack and ends up making sears tower and not her dude takes my childhood lego idea and publishes a solid book on the concept. So proud of their achievements. Mashallah

 

[bluesky]

I have shown in my structural concept that it is possible to build a 3,262 feet high (one kilometer) skyscraper. At present, if you want to build a building beyond the 20th floor, you have to pay attention to issues related to wind and earthquakes. This requires some additional structural methods that cost a lot of money. But in my structural concept, these are not necessary.

- If it is shear walls in tall structures, they have been in existence for about a hundred years.

- There are also VERTICAL transverse beams in between two columns at the corners that also withstand the horizontal wind/ seismic force that try to twist and break a structure at the corner.

- Shear walls are also provided in the staircase and lift/ elevator rooms. An open floor for these rooms is weak and so, it is strengthened by providing shear walls on the three sides. The 4th side remains open for the entry of the users.

All roads go to Rome and all loads (Vertical: Dead and Live, and Lateral: Wind and Seismic) go down to the foundations and from there to the soil. Nobody should expect tall buildings can be constructed in BD soil unless stone bedrocks are discovered below, say. 50m.

Guys, please note that although wind/ seismic loads act horizontally, they ultimately add extra temporary vertical loads to the piles on the opposite side of the structure. Please note that these loads are temporary, but have the strength to destroy a structure built on weak soil.

So, better we do not expect very tall buildings to be built in or near Dhaka.

 

[PoondolotoPandalum]

What's happening to the legacy tower in Purbachall city? Has construction started yet?

I bet it'll be overbudget and massively delayed, based on our inexperience building such a structure in our soil, not to mention the inevitable corruption.

Wasn't there also a plan to build a 700m+ skyscraper in the same area? Will that be approved?

Either way, they're not really priorities, more of a vanity, trying to paint the picture of a Bangladesh that doesn't exist yet, but "might" exist in the late 2020s

 

[fallstuff]

What's happening to the legacy tower in Purbachall city? Has construction started yet?

I bet it'll be overbudget and massively delayed, based on our inexperience building such a structure in our soil, not to mention the inevitable corruption.

Wasn't there also a plan to build a 700m+ skyscraper in the same area? Will that be approved?

Either way, they're not really priorities, more of a vanity, trying to paint the picture of a Bangladesh that doesn't exist yet, but "might" exist in the late 2020s

They probably haven't figured out the kick backs on this deal. Once that little detail is sorted out you're going to hear more !

 

[Bilal9]

What's happening to the legacy tower in Purbachall city? Has construction started yet?

I bet it'll be overbudget and massively delayed, based on our inexperience building such a structure in our soil, not to mention the inevitable corruption.

Wasn't there also a plan to build a 700m+ skyscraper in the same area? Will that be approved?

Either way, they're not really priorities, more of a vanity, trying to paint the picture of a Bangladesh that doesn't exist yet, but "might" exist in the late 2020s

There are three main towers planned, the tallest one (depending on the phase of the moon and the amount of ganja in the adda) is going to be 96 floors or 111 floors. 96 is the more credible I have heard. There are also going to be two other towers, a 71 story and another 52 story (wink wink). Chetona rears its head again. Frigging sycophants. These are the same Chetona AL f*ckers who get real touchy and mad when you mention "71 er gandagoler shomoi." and claim to be muktijoddha when they weren't even born at that time. Fakes all around. I mean we all love our country, but when you put Hasina on a Hindu-like Devi pedestal, really....it puts North Korea to shame.

Any how there are also going to be a whole slew of other 40 plus story buildings around the campus, supposedly some 30 or more of them, massive project which will require major investments and resources, both technical and logistics wise. It will be Bangladesh' Burj Khalifa, in a manner of speaking, if it ever gets built.

They probably haven't figured out the kick backs on this deal. Once that little detail is sorted out you're going to hear more !

That is right on the money.

Also - other reasons are that there are a dozen different mega projects going on right now in Dhaka itself consuming massive amounts of resources and equipment. Too much to handle by all the govt. depts., even with the promise of huge graft. Purbachal Expressway, Padma Bridge near dhaka, Airport 3rd terminal, BRT to Ashulia etc., North-South Expressway, Metro Line 6 none of these are completely done, and there is Metro Line 5 (underground) which is coming up July 2022 - which is going to be another juggernaut mega project in itself. I bet they are going to bring in the Karnaphuli tunner digger machine to complete that one.

Metro Line 5 from airport to Kamalapur will be underground, but there will be a side route to Purbachal which will be on viaducts like Line 6. The DMTCL is waiting for Line 6 to be completed, then they can start on Line 5. I understand soil testing is already done. Looks like not much will happen before they complete the Purbachal eight-lane Highway (plus service lanes) on which they have started asphalt carpeting already.

Nobody should expect tall buildings can be constructed in BD soil unless stone bedrocks are discovered below, say. 50m.

@bluesky bhai - does soil friction or density have anything to do with load bearing capacity? I understand Purbachal site hardly floods and that soil substrate is older than the alluvial substrate closer to the main rivers we have. Mymensingh area soil (lal etel mati) is even older and much stronger in density.

I saw a video of the construction of Merdeka 118 in KL recently (world famous construction firm Turner USA was involved). They built the sheer wall core first on a bed of pilings about 200 feet deep, then built the floors slowly around the core. I don't know if you go down to 200 or more feet with piling, Purbachal towers may be made feasible. What I saw on the Merdeka video, they did not hit bedrock either but made do with plenty of pilings.

Merdeka PNB 118 (KL 118) Facts and Information

Merdeka PNB 118 or KL118 which is its formerly used name, is a 118 floors megatall skyscraper currently being built in Kuala Lumpur, Malaysia. Below are some facts and information of the skyscraper. Name: The official name of the tower is Merdeka PNB 118 or simply Merdeka 118. Merdeka means...

thetowerinfo.com

This Turner document explains the piling method.

https://docplayer.net/85221000-Merd...uang-shi-yan-fang-fa-zhi-cai-yong-fen-xi.html

 

[bluesky]

@bluesky bhai - does soil friction or density have anything to do with load bearing capacity? I understand Purbachal site hardly floods and that soil substrate is older than the alluvial substrate closer to the main rivers we have. Mymensingh area soil (lal etel mati) is even older and much stronger in density.

Yes, the density of soil determines the friction coefficient of soil vis-a-vis the steel pile perimeter. However, BD soil is mostly alluvial/ silt. Most of the country was once sea and then became rivers that carried silt from the Himalayas.

Talking about clayey soil (Etel Mati) in Mymensingh, this kind of soil may also be most precarious. Instead of working upwards to resist the vertical loads, some
clayey soil may go downwards instead. So, a design engineer may not decide how the load will act on the soil he is considering before he gets all the information on the SPT (Standard Penetration Test).

I saw a video of the construction of Merdeka 118 in KL recently (world famous construction firm Turner USA was involved). They built the sheer wall core first on a bed of pilings about 200 feet deep, then built the floors slowly around the core. I don't know if you go down to 200 or more feet with piling, Purbachal towers may be made feasible. What I saw on the Merdeka video, they did not hit bedrock either but made do with plenty of pilings.

Last time one poster was saying about the Shanghai Tower that there is no bedrock. Then, I checked the soil information and found there are bedrocks below to sustain the heavy loads.

I have checked the link you have provided. But, there is no words on the soil investigation at all. So, no one can be sure there is no bedrock below the piling.

Increasing the number of piles may help to minimize loading on each of the single piles. You can increase the piling area and double or triple the number of piles. For example, the building base is 200m x 200m or 40,000m2.

But, if you spread the pile area to, say, 400m x 400m or 160,000, you get four times more area and the number of piles becomes almost four times. So, the loads on each pile become also 1/4th.

But, this may not be the best solution. economy-wise. Note also that Dhaka is located in an earthquake-prone zone. A designer will never overlook this factor and commit suicide after something happens.

I actually cannot say anything definite until I have the opportunity to read through the boring log data of a proposed site.

 

[Bilal9]

Yes, the density of soil determines the friction coefficient of soil vis-a-vis the steel pile perimeter. However, BD soil is mostly alluvial/ silt. Most of the country was once sea and then became rivers that carried silt from the Himalayas.

Talking about clayey soil (Etel Mati) in Mymensingh, this kind of soil may also be most precarious. Instead of working upwards to resist the vertical loads, some
clayey soil may go downwards instead. So, a design engineer may not decide how the load will act on the soil he is considering before he gets all the information on the SPT (Standard Penetration Test).

Last time one poster was saying about the Shanghai Tower that there is no bedrock. Then, I checked the soil information and found there are bedrocks below to sustain the heavy loads.

I have checked the link you have provided. But, there is no words on the soil investigation at all. So, no one can be sure there is no bedrock below the piling.

Increasing the number of piles may help to minimize loading on each of the single piles. You can increase the piling area and double or triple the number of piles. For example, the building base is 200m x 200m or 40,000m2.

But, if you spread the pile area to, say, 400m x 400m or 160,000, you get four times more area and the number of piles becomes almost four times. So, the loads on each pile become also 1/4th.

But, this may not be the best solution. economy-wise. Note also that Dhaka is located in an earthquake-prone zone. A designer will never overlook this factor and commit suicide after something happens.

I actually cannot say anything definite until I have the opportunity to read through the boring log data of a proposed site.

Thanks @bluesky bhai, if I can find the piling and boring test data, I will post it here...

 

[bluesky]

Thanks @bluesky bhai, if I can find the piling and boring test data, I will post it here...

I have checked and found that Malaysia is not in an earthquake-prone zone. But Dhaka lies very near to such a fault that runs from the Himalayas to Thailand. Thailand has a hot spring because of this fault.

I believe a Japanese famous company like Kajima should be involved with any such Purbachal project. Japan and California (also Hawai) fall in the earthquake zone. So, Kajima-like companies have long experience in constructions in a seismic zone.

Now, please read what a book titled "Foundation Design" (P. 18) by Wayne C. Teng that says on foundations on silty soil which is prevalent in BD.

"-----Because of the fine particle size (passing No. 200 sieve), this (cohesionless) soil has the following undesirable characteristics:

1. Low shear strength immediately after load application,
2. High capillary and frost susceptibility,
3. Low permeability,
4. Low relative density-difficult to compact.

Note that silts have a natural low density that was seen in the construction of Padma bridge foundations. Piles in two of those foundations had to go 120m below the surface, and the number of piles increased.

To tell you frankly, even then I am worried about this 120 me long as well as other piles. I believe a Kajima-like company would have done it differently: either a pneumatic caisson or compaction of silt by the explosion of hundreds of tiny dynamites through at least a 100m depth.

Note that the dynamite explosions compact the silt and thus increases the density to give stronger skin friction to the piles.

You have to read through the scripts on how the compaction of soil was done below the Kaptai dam. It was done by a Japanese company, probably Kajima, who exploded small dynamites. Was it the following book that refers to Kaptai Dam, I am not sure. The book was in the library of the company I was employed in and I do not have a copy.

Foundation Engineering Handbook
by Fang, Hsai-Yang

But, good or bad, the Chinese company took a different approach in the Padma Bridge foundations. However, I must say their approach to lengthen the piles did not show any technical ingenuity. It was as a usual procedure.

 

[Paul2]

I have checked and found that Malaysia is not in an earthquake-prone zone. But Dhaka lies very near to such a fault that runs from the Himalayas to Thailand. Thailand has a hot spring because of this fault.

I believe a Japanese famous company like Kajima should be involved with any such Purbachal project. Japan and California (also Hawai) fall in the earthquake zone. So, Kajima-like companies have long experience in constructions in a seismic zone.

Now, please read what a book titled "Foundation Design" (P. 18) by Wayne C. Teng that says on foundations on silty soil which is prevalent in BD.

"-----Because of the fine particle size (passing No. 200 sieve), this (cohesionless) soil has the following undesirable characteristics:

1. Low shear strength immediately after load application,
2. High capillary and frost susceptibility,
3. Low permeability,
4. Low relative density-difficult to compact.

Note that silts have a natural low density that was seen in the construction of Padma bridge foundations. Piles in two of those foundations had to go 120m below the surface, and the number of piles increased.

To tell you frankly, even then I am worried about this 120 me long as well as other piles. I believe a Kajima-like company would have done it differently: either a pneumatic caisson or compaction of silt by the explosion of hundreds of tiny dynamites through at least a 100m depth.

Note that the dynamite explosions compact the silt and thus increases the density to give stronger skin friction to the piles.

You have to read through the scripts on how the compaction of soil was done below the Kaptai dam. It was done by a Japanese company, probably Kajima, who exploded small dynamites. Was it the following book that refers to Kaptai Dam, I am not sure. The book was in the library of the company I was employed in and I do not have a copy.

Foundation Engineering Handbook
by Fang, Hsai-Yang

But, good or bad, the Chinese company took a different approach in the Padma Bridge foundations. However, I must say their approach to lengthen the piles did not show any technical ingenuity. It was as a usual procedure.

One more option I saw over the years of travelling to engineering projects around the world: cryo-stabilisation.

A giant freezer is built to freeze the soil around the foundation perimeter. Frozen soil expands, and compacts the rest of the soil laterally.