From the GMA Techline
RE: Marine works, geotextile characteristics
I want to know your point of view concerning the selection of the correct geotextile as a separation layer below a submerged reef. The submerged reef section … includes a 2–3 ton double layer laid directly on a geotextile, without insertion of sublayer, because they wanted to reduce the cost.
The question is: How could I select the right geotextile for this specific use? I think that the most important parameter I have to consider for the correct geotextile selection is the static puncture strength (EN ISO 12236), which should be compared to the stone weight. Is this right? And in this case, what should be the ratio between the geotextile static puncture strength and stone weight?
Is there any other parameter that I have to consider? In my opinion a geotextile of 600/800 grams per square meter should be enough.
Thanks in advance for your advice. Best regards.
(Fran | Italy)
Reply: Thanks for your question that is, indeed, a good one. I do agree that puncture is the major mechanism but it might be more than just static weight since the influence of impact might be a factor. Rather than do impact tests, per se, I would add a factor depending on the contractor’s operation in the field.
A second issue that comes to mind is the angularity of the stones, which can also be an influence.
Rather than giving you a direct answer of 600/800 g/m2, we will send to you a 1986 paper where we looked a different variations from both static puncture and impact perspectives. Do let me know if this helps.