Originally Posted by TomG
I'm still waiting for answers to my questions. But I will suggest that you go out and get NCMA certified, the class will teach you about the importance of geo-grid in walls and that "just using correct soil type and compaction" is not enough for taller walls. While your at it get ICPI certified also.
Tom, lets stay on subject, shall we?
As I stated - geo-grid is intended for retaining walls, it's intended for VERTICAL structures. Keyword "VERTICAL". Vertical. Vertical. Vertical.
Staying on subject in reference to your picture of the granite, that is NOT a vertical structure, as I stated.
Here is something I copied and pasted for you from retainingwallexpert.com, again, notice the use of the word "vertical":
Imagine a small pile of sand on a card table....got it?
Okay - besides being a mess, you can picture that the sand will
just run onto the floor, no matter how much sand you try to pile up!
It will run off the table because sand won't stand vertically.
Now - envision putting beach towels down on the table that are
the exact same size and shape of the table. Imagine these beach
towels between 1-inch thick layers of sand! By repeating layers
of towels and sand over-and-over again you can make a really
high, vertical column of sand! You just did what GEOGRIDS
do for walls that are 40 to 50 feet tall!
So, GEOGRIDS reinforce the soil or sand to make the sand
stand up nearly vertically! Geogrids such as Stratagrid are
manufactured with high quality in a variety of strengths.
Now, the other day I editted a post, but it was after the 10 minute period allowed for post editting, and being the super important man that I am - I was on a jobsite. Grid can also be used for soil stabilization, (staying on subject and in response to your statement) but in YOUR photo you show it being used as geo-textile fabric.
We do alotta concrete demolition, so I see what benefits of wire and rebar do in a prospective that many folks do not see.
In relation to the GRID in YOUR photo:
GEOGRID is to similar to soil what reinforcing steel is to concrete
Much higher loads can be carried by the soil structure.
Again, back to your PHOTO - in order for that statement to be true with your job, your grid would have to be DEEPER in the ground. Which is why I mentioned that "soil settles from the bottom up". As what your picture shows the grid is close to the surface.
On my old computer I have a video showing what happens without grid. I know I posted the video on a hardscape forum, it may have been 3 yrs ago, but I'm not sure if it was this forum or another.