Auguri a tutti! In questo periodo non c'è richiesta dei soliti lavoretti, mi sono pertanto dedicato (con la fantasia) a progetti più importanti, tra cui le isole artificiali.
Ecco alcune ulteriori informazioni che sono riuscito a trovare (c'è molto poco in rete).
In Canada sono state costruite alcune isole artificiali per pozzi di petrolio, in ghiaia.
Attualmente si preferisce utilizzare sabbia dragata con impianti aspiratori, e rivestire il tutto con geotessile + una "corazza" esterna di massi, più grandi dove l'energia idraulica è maggiore. Vi cito alcuni dettagli, tratti dal forum eng-tips:
Manmade islands can be built from many materials. The critical thing is the amouring on the outside.
I was involved with one about 1km of the coast in the Clyde Estuary in Scotland It was in about 20 m of water.
It was basically dredged sand in a pile delivered by suction dreger and a 18' pipeline, a geotextile layer on the outside and some rock armouring, rocks were about 2 to 3 ft size.On more exposed locations the external rocks get larger I think up to about 5 tons each if I remember. The outer layers with progressively smaller rocks in layers below and of course geotectiles to prevent washout of fines.
The island in Scotland was a temporary facility to build oil platforms.I do not know how long it lasted or if its still there.
Prepakt Honk kong and Gammon International did the original site investigation for the Honk Kong airport so I am sure we still have some files somewhere.
Intrusion Prepakt
www.marineconcrete.com Ancora:
There have been a lot of artificial drilling islands put in the Beaufort Sea (north of Alaska and Yukon Territory) over the years. A few friends from my old days at Golders were working on them for Dome Petroleum back in the late 70s or early 80s. Can do a search for papers by Mike Jeffries who was with Golders, then Dome. I think that there must have been some papers in the annual Canadian Geotechnical Conferences on the subject. Mainly, if my recollection is correct, they are made of gravel - huge islands. I think on my google search, some environmental group was pining about all the gravel used. But, you are right in that not much shows up on searches.
Back in the mid-1970s, Golder was working on vacuum sand islands - huge "rubber" bags filled with sand and then using a vacuum to suck out the air. Made them very very dense. Don't really know what came of it though on a practical sense. I saw some lab work being done on scale models.
