Underwater breakwater «Grebenka»
English version | Русская версия
PROBLEM
The Issue of Shore protection seems to be rather acute in the world & in some regions even sharp.
E.g. especially tough situation is on Portuguese Atlantic Shore where in the North sector along 120-km shore line up to the city of Porto bank erosion due to sea waves not only washes out the beach but already even causes landslides & rockslides which endangers buildings & some of it are to be demolished due to risks to inhabitants (e.g. in Paramos village). Similar problem regions could be found in many countries.
And specialists predict that current climate changes lead to increased strength & frequence of storms with more high waves.
TRADITIONAL WAYS & LIMITS
Usually the task of shore protection is achieved by erecting different kinds of Seawalls, Piers, Groynes, Cutwaters, Bunes, Artificial Reefs etc. But such traditional constructions demand a lot of materials & plenty of time, while common components to it (concrete, steel, etc.) are vulnerable to sea water corrosion & destruction by powerful waves which shortens its life & pollutes the environment. It costs a lot but very often erection of these constructions is lagging behind shore demolition by waves.
Traditional technologies of beach nourishment by adding each year more & more sand to the beach instead of great amounts washed away by sea are only temporally & relatively effective but very costly & devastating for places from where sand is being extracted both in-land or off-shore.
OPPORTUNITY FOR SOLUTION
So the idea is to use up to date materials which are strong & corrosion-proof & long-standing & easy to install & ecology safe – thus saving a lot of money & time. One of such options is to use composites (Fiberglass & Basalt Fiberglass) as they have got all mentioned above characteristics: it is competitive in strength & durability to steel & concrete (tensile strength of Basalt Fiberglass is more than 70 000 PSI) but much less in weight & not vulnerable to sea or any other corrosion. So it’ll work to protect shores many times longer than traditional materials. And it is easy & quick in installation & much less expensive.
TECHNICAL IMPLEMENTATION & ADVANTAGES
Our proposed technical solution – we call it “Comb” — is a kind of artificial reef made of mentioned composites. The construction allows not only to withstand waves strikes & to break waves & save beaches & shore but – due to simultaneously elastic & tough features of composite – makes this job more efficiently by amortizing to the wave pressure & absorbing kinetic energy of the wave. The elements of construction are placed so that it breaks waves but allows water to penetrate & does not create closed “dead” zones behind it, while amortizing process & poplling even helps to enrich the water by air bulbs.
The construction can be placed on any lay of the bottom with different angles of slope. It is capable to cover up to 24 meters in height thus intercepting most of incoming waves & breaking it. There is technical solution to increase this range even more if necessary. Mentioned construction consists of as many modules (each one 10-12 meters wide) as required for particular place, which are installed in a line thus creating a prolonged artificial reef protecting the shore & waters behind it.
Due to less weight than concrete or steel analogues our composite Comb could be assembled nearby on the shore & placed very quickly both from vessels or land. It is possible to remove it or replace or repair it when necessary.
For the sake of steadiness of Comb on the bottom against waves & tides & currents it is made heavier under water by injecting concrete inside construction (where concrete is isolated & protected from aggressive sea water). Thus weight of one module of Comb 12 meters wide could reach form 15 MT to 120-140 MT.
EFFECT
Studies in Russian Sea & Ocean Scientific Centers show that height of waves thanks to the Comb is decreased up to 4 times; reflection coefficient is 0.2 only, while wave absorption coefficient is 0.89.
As for financial aspect our experience in Russia shows that proposed Comb costs at least twice less than similar concrete construction.
And period of installation decreases form several months to several days or even shorter.
DEMONSTRATION OF PROCESS
We attach here some drawings & short video describing how our Comb works.
PATENTS
We’ve got Russian Patents 187014, 189520 & 189521 for different technical options of our Comb construction (Bottom-based, Floating, Combined Bottom-Floating) & are now in process of International Patenting within the framework of PCT (PCT/RU2019/000043) with priority date established since October 2018.
COOPERATION & CONTACT
We hope this general information given above allows to estimate if such a construction is helpful to solve the problem of shore protection in your region.
Ready for installation
In case of your interest we are ready to supply required quantity of described constructions adjusted to particular place & conditions or to discuss any other ways of cooperation.
Download technical report (PDF 5.23 Мб.)