ecology block retaining walls w/ geogrid
ecology block retaining walls w/ geogrid
(OP)
Because it looks like a simple, inexpensive retaining wall, I get a lot of requests from homeowners and some builders to design eco-block retaining walls. Many of them, especially the homeowners, incorrectly believe that eco-blocks can effectively form tall gravity walls, even to ridiculous heights. One thing they are correct about, though, is that eco-blocks are cheap, or at least cheaper than segmental wall systems like keystone. In our area, I have found that with clay backfill, eco-block walls are only reliable to 4' above ground (the first block is buried 1', and there is a 1' cap block) and maybe 6' with granular, freely draining backfill past the angle of internal friction, and with a 6:1 batter. To go any higher, especially without any batter, would require geogrid. Does anyone have any experience or insight into the design of an MSE/ecology block wall? How effective is the friction grip on the geogrid by the blocks?
Thanks
Thanks





RE: ecology block retaining walls w/ geogrid
If your client is going more than about 4 to 5 feet, insist on a segmental wall system. Stick to your guns - you're on the right track.
Do you have much of a problem with the clays washing between the eco-blocks?
RE: ecology block retaining walls w/ geogrid
I'm thinking that maybe a bolted conxn with cable and a deadman might work, but then I'd have to worry about corrosion.
Damn I hate cheap clients, they always make me think.
RE: ecology block retaining walls w/ geogrid
RE: ecology block retaining walls w/ geogrid
Thanks,
Chris
RE: ecology block retaining walls w/ geogrid
Good luck.
RE: ecology block retaining walls w/ geogrid
RE: ecology block retaining walls w/ geogrid
I have some questions re your post. When you say "reinforcing steel mesh" are you referring to a pre-fab mesh that would normally be used in a concrete slab? What designation mesh or what size bar would you be talking about? Can you give me some more details on how this would be built? What do you mean by "shutter?"
JDMM,
Ecoblocks are blocks manufactured locally out of return concrete, probably the same as your "Lock Blocks" except they are 2x2x6, with semi-cylindrical locking sections (male at top, female at bottom) They tend to suffer from lack of uniformity, i.e. there are often gaps of an inch or more between the blocks when stacked, which could affect geogrid effectiveness (pullout). I'd appreciate any insights you could offer.
Thank you,
Chris
RE: ecology block retaining walls w/ geogrid
Thread255-43311
We did a quick test stacking two blocks with a piece of geogrid inbetween. The geogrid was Tensar UX1500HS. Using a a 16" wide piece of geogrid I wove a piece of barstock through the free end and we pulled with a backhoe. With no filler the the geogrid pulled out easily as you mentioned because you do not get a tight fit between the blocks (and the geogrid was placed between interlocks so they gave no contribution). The next time we put the geogrid down and mixed up a cement grout and trowled it over. I think we did it on a Friday, so it would have cured over the weekend, 3 days. Pulling this time ended up pulling the blocks over, so >3000lbs/ft connection strength. More than I needed.
Hope this helps.
RE: ecology block retaining walls w/ geogrid
RE: ecology block retaining walls w/ geogrid
They do provide computer programs for their products; but these can be a bit difficult to operate. If used, they should be verified by independent calculations. I have seen reports and design procedures from geotextile vendors; but this is some time ago. Check with Nilex, or Layfield plastics in Calgary, Alberta, Canada.
I will look for the references, and advise; but not this week. Sorry.
RE: ecology block retaining walls w/ geogrid
RE: ecology block retaining walls w/ geogrid