Editor’s introduction: A great many alternatives have been proposed for mitigating the damage from the ongoing oil spill in the Gulf of Mexico. Geosynthetic technologies have certainly been part of active solutions, from oil booms to floating geosynthetic tubes to sock normally used for stopping sediment migration (and, in this case, perhaps filled with human hair). But, so far, these solutions have focused mostly on surface collection of oil.
In an online discussion with I-CORP‘s Ian Peggs, SKZ‘s Helmut Zanzinger proposed some loose ideas on how geosynthetic technologies might be incorporated into stopping the spill from its point of origin.
We reprint his comments here by permission and invite other ideas from the global geosynthetics community. They are needed. Send your thoughts to chris@geosynthetica.net and please note if may share them with Geosynthetica’s readership. — Chris Kelsey, Editorial Director.
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GOING AT THE SOURCE OF THE PROBLEM
First Email
Dear Ian,
Every day we realize on TV that BP is not able to find a method to close the leakage of the oil pipeline in the Gulf of Mexico. Is there nobody able to find a solution? Last week we were shown excellent applications with geosynthetics at the 9th International Conference on Geosynthetics. Why is nobody trying to use geocontainers, geobags and lining systems as a flexible solution?
Of course, any solutions must be stable against erosion and strong enough to fulfill all needs.
To solve such a disaster by using simple geosynthetic solutions…I could imagine that it could be possible to cover the leak with a large and strong sheet of reinforced geomembranes. The edges should be jointed with heavy geocontainers. The whole system could be positioned by fixing each geocontainer with correctly designed air-filled ballons. By releasing the air out of the ballons the whole system of geomembrane and geocontainer can move slowly down in a controlled manner to the ground.
After positioning of that system at the ground the whole geomembrane has to be loaded with a lot of geobags. When a sufficient confining pressure is reached the leaking must stop.
If the reinforced geomembrane is not strong enough, a combination of an extra reinforcing layer above the geomembrane can support the system.
For us, it is unbelievable that this leak has not yet been solved.
Follow-up email from Dr. Zanzinger
My idea was that everything has to be removed so that a flat cap could be placed. The oil pressure might be very high. Anyway, it is a question of the design. When the surcharge is high enough and if the covered area is large enough.
In a first step, a strong and large woven fabric could be placed on the ground above the hole. It must be fixed and loaded on the edges with heavy sand-filled geocontainers. The woven fabric is permeable and must have a very high tenacity (eventually, aramid wovens). Oil would pass through.
In the second step, further geocontainers with very high flexibility (low filling ratio) will be placed on the same area–the oil flow will be reduced to a certain degree. Start from the outside and then place them in the direction of the centre (hole).
After the oil pressure is reduced and also the upstream forces are reduced, the third step can start with placing a real watertight “carpet” on this hill. In this case, the geocontainer will be placed first in the centre and after that going stepwise to the edges of the “carpet”.
If the flat placing of the “carpet” is not possible, geocontainers shall be placed first around the blow-out preventer to form a platform around the hole. Finally, even with the oil tube inside a covering of the area in the above-described manner might be possible, but you need many more geocontainers and the area will be wider.
Eventually the carpet could also be connected with a few funnels.
My description sounds rather easy, but…thoughts are free.
– Helmut Zanzinger
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Editor’s Conclusion: Thoughts are free, certainly; but they are the seeds of great ideas and actions. We invite more comments from Geosynthetica’s audience, both in response to (or building upon) Dr. Zanzinger’s thoughts and other potential angles of response to the Gulf situation. We thank Drs. Zanzinger and Peggs for their time. And we hope you will take a moment to look into two forthcoming SKZ events that will advance other discussions and professional exchange in construction and engineering with geosynthetics:
- 3rd International Symposium on Geosynthetic Clay Liners
- 3rd Geosynthetics Middle East
