Introduction - Dubai Floating Island Project in Progress - Designer

(.) #22

Hello Mr. Duman;

Welcome to the discussion forum. I hope you like it here.
Your experience is impressive.
Mr. Tapkan’s experience is also impressive.

Respectfully yours;


(Ali) #23

Dear Spark

Thank you for your kind message, i like it here



(Wilfried Ellmer) #24


Dear Ali,

I find it interresting that you introduce yourself as Civil Engineer with experience in marine structures.

Can you share a bit what you have been working on and what you are interested in ?

The bottleneck in Seasteading is very much caused by this traditional seperation of civil engineering and marine engineering so people with capacity to bridge that gap are very important.

Kindest Regards

Wilfried Ellmer

(Ali) #25

Dear Wilfried

Thank you for your interest. I am a civil engineer who especially worked for caisson supported port,shipyard construction projects. This is a kind of block type port construction method. We need semi-submersible/submersible platforms to construct caissons up to floating conditions to transport sinking area. Please see the photo below that showing one of the our projects in Turkey;

Additionally, we build huge caissons for foundation of a suspension bridge construction projects, with floating conditions with weight of 37.000tonnes up to installation to project site. Please see photos below for Osmangazi Bridge Project in Turkey

In the World, temporary/permanent floating structures are important parts of some of the civil engineering projects, floating airports, floating bridges, temporary floating port&bridge construction elements etc. I was responsible for the construction, sinking&towing&installation operations of the caissons. I was responsible for temporary floating stability (GM, draft, balance weight) calculations. This is the most important calculation for caisson supported structures

That is why i would like to join Seatsteading, because your projects include floating breakwaters, houses, islands with many civil&structural issues this is not just marine engineering

If you want i can send e-mail to you for more detailed photos
And you can read details from my Linkedin profile

Kind Regards

(Wilfried Ellmer) #26


Dear Ali

Great to have you here. Finally somebody who can offer an educated opinion worth listening to.

I am @nautilusmaker

I imagine you googled me up just as i googled up you .

If i got it right you are a collegue of PK Mehta - so here is my first question - as you are in the field -

• What is your opinion about his visionary prediction that in the 21 st century ocean based construction might well pass land based construction in importance. ( ref )

(Ali) #27

Dear Wilfried

I am not the collegue of PK Mehta, my first time regarding the book, i will have a look

(Wilfried Ellmer) #28

@aliduman | sorry “peer” is probably a better word than “collegue” | meaning you are not working with him in the same group you work in the same field at the same level (in another engineering group on similar projects)…this is why your opinion counts.

Is his vision considered outlandisch or shared by most of his peers who have insight in marine concrete engineering.

• Do you see a possibility to create a New Venice or New Atlantis on floating concrete foundations ?

• Do you think floating foundations can compete with Singapore and Dubai Landfill projects on the real estate market ?

• What would you estimate as cost per real estate square meter (Singapore landfill goes at USD 700) and this is billion dollar business already.

You must have had some deep thoughts on that ... can you share ?

(Nick Gencarelle) #29

Mr. Duman, Nice to have your skills and experience here. Have you or are you using any composite reinforcements like my basalt rebars and mesh and fibers? And have you used any ultra high strength concretes? Nick

(Ali) #30

Dear Nick
Thank you for your kind message. I never used basalt reinforcement, for permanent floating reinforced concrete structures it would be usefull to avoid corosion.
I never used ultra high strength concrete too but used C70 concrete prestressed spun pile supported marine structures, that was my master thesis. Please give me details. Regarding floating cities i don’t think we need such kind of concrete, am i right?

(Nick Gencarelle) #31

Hi. Yes our UHPC has been tested by the US Army Corps of Engineering for over twenty years now in blocks of concrete placed in the ocean off the coast of Maine-very rough waters.They have not seen any degradation to even the top surface yet-no chloride penetration. So a much thinner stronger and longer lasting solution is available-even if this is just used as a coating on regular concrete with our basalt volcanic rock reinforcements. Basalt is 2-3 times stronger in tension than steel yet over 70% lighter and will not corrode. Basalt is very resistant to salts and acids and corrosive chemicals, high and low temperatures and does not conduct electricity or harbor bacterial or microbial growth. You can use a size or two smaller than steel and we can put the equal of 8 containers by weight of steel in 1 container of basalt saving over $35,000 to begin.

(Nick Gencarelle) #32

As we know salt water and steel in concrete has a very limited lifespan.

(Nick Gencarelle) #33


These walls made right at my beach less than ten years ago I think are totally shot open.

(Ali) #34

Dear Wilfried

Sure, i can share my thoughts

I had a quick look to book. I generally agree with his vision, great book. High-stregth lightweight aggregate concrete would be usefull for floating concrete structures, because decreasing concrete weight means increasing floating capability (with required balance weight below sea level if needed). In the world, floating airports, bridges, underwater tunnels etc. are commonly used.

  • It is possible to create new cities on floating concrete foundations, i believe it will be common construction method against to global warming&rapidly increasing population

  • As of now i don’t think floating foundations can compete with Singapora and Dubai Landfill projects. Because they use sand from see bottom for foundations means that required material for foundation comes directly from construction area, generally without transportation, big advantage.

  • Unfortunatelly i can not say anything for price, because we construct floating structures for different purpose, heavy structures


(Wilfried Ellmer) #35

@aliduman |

Dear Ali

I hoped you would say something like that. In a way i see you confident that the actual methods used in marine concrete engineering are “sufficiently good”

So what we have at hand, can serve as foundation of a floating city - in spite of the pictures of concrete spalling caused by rusting rebar that @NickGri posted.

In a way i do not want this to become another “versus debate” where it comes to a polarization of the benefits of steel rebar versus the benefit of basalt rebar.

I think we all are in consensus that the "vulnerable component of the “composite material concrete” is in fact the rebar.

We are also aware that there are horrible examples of concrete falling apart due to rebar rusting.
To be fair it needs to be said that there are also “surprising examples of non rusting rebar in marine ambient for many decades”.

It is no secret that the North Sea concrete based floating oil infrastructure, far from falling apart after a few decades, just was upgraded in “service life expectancy” and surprisingly little damage was found after decades of exposure by independent surveyors.

It is also known that concrete ship SS Peralta built 1921 and on a cero maintenance shedule since then is still floating.

So i would like to invite to a kind of consensus that the horrible spalling pictures correspond rather to a “incompetent builder” getting the mix wrong and failing to apply “good concrete practice” than to a universal “non fitness of steel reinforced structures for the marine ambient”.

Having said that it must also be mentioned that the traditional marine concrete engineering is vulnerable to errors of the contractor resulting in desasterous service life reductions.

So the question if it is wise and neccessary to look into alternatives to steel rebar is still on the table - altough “existing structures have shown a good overall performance” over several decades.

So nobody expects the structures built by @aliduman and @Kerim_Tapkan to have a service life of less than 100 years what makes them compareable to any land based building.

@NickGri | @aliduman | @Kerim_Tapkan | @Matias |

If the “expert panel” is still with me on that consensus the interresting questions that are on the table are:

• If we have technology at hand to build floating cities where is the bottleneck that avoids that this is happening ?

• Is it the cost factor ?

• What are the markets floating real estate would have to compete with ?

any comments on that ?

Pieces of the North Sea Oil Infrastructure | Ekofisk | Marine Concrete Engineering |

Tubular marine concrete structure | Troll A | 303m deep underwater | decades of deterioration free service | 1m wall thickness | 24 m tube diameter | what is out there already | works surprisingly fine |

(Nick Gencarelle) #36

Somewhat agreed. You point the possibly “one” concrete boat still in existence maybe there are a few out of the many dozens made. I would think those that survived probably have had some serious maintenance and paint as well regularly. Yes pilings in the water below the waterline probably last much longer as there is little oxygen getting to them. A boat or barge moving up and down will have much more exposure. Weight considerations, and total costs are yes bottom line items to be considered. Depending on if the project is to stay in one place permanently or to be moved occasionally, how deep underwater is wanted, so the total weight of the structure with everything and everybody onboard? A lot of maritime engineering and design considerations of course. Reducing weight on such a structure and having much less repair and maintenance are what using the right materials upfront reduce costs for considerably.

(Ali) #37

Dear Wilfried

Sorry for confusion, ı am not confident to use actual methods used in marine concrete engineering. I mean, do we need ultra-high strength concrete for floating structures? Just strength issue. We need to check the relationship between strength&wall thickness&weight for floating concrete structures to ensure the floating stability. Thank you for your and @NickGri detailed info regarding basalt volcanic rock reinforced concrete, i will look for it.

(Ali) #38

Hi, thanks for detailed info, seems interesting

(Nick Gencarelle) #39

Yes indeed. The weight of a UHPC reinforced with the basalt when it has no large aggregates and is much thinner yet still much stronger than a regular concrete is what I believe is the difference. Again a much longer life with less repairs, better impact and ductility, and actually being that much less material probably less expensive in total.

(Nick Gencarelle) #40

1 meter thick that’s a whole lot of concrete! Probably with coatings on it as well. What is the cost of that? and again underwater is yes less issues with corrosion. Basalt rebars can be hundreds of meters long so no 20-40 foot pieces of rusty steel and sharp ends and overlaps loss of rebar and the time to tie them together.

(Matias Volco) #41

Hello Ali, thank you for your contributions.

I was wondering, in the context of the Floating Islands projected for Polynesia, how coastal environmental concerns already impact the cost and approach of traditional Landfill?

In the ongoing works described in the video the sand is imported from 1000km away