Let's talk about GeoTex

Discussion in 'Heavy Equipment & Pavement' started by Scag48, Apr 12, 2008.

  1. Scag48

    Scag48 LawnSite Fanatic
    Posts: 6,067

    Alright guys, here's the deal. My dad called me this morning with some inquiry about GeoTex. He got called to go do a retaing wall bid, wall height is 10 feet tall and he has been provided the engineering specs, so he doesn't need to find an engineer, it's already been done. He said it's fairly thorough, except for where to tie the GeoTex to the blocks. The engineering calls for a certain type of block, it is a batter type block so it's not vertically pinned, which I'm curious about. I can see how it would be simple to attach the tex between blocks using the pin system, just run a loop of the material through the pin, drop a block on top and keep on going. Second question pertains to attaching the other end of the material to the slope. I haven't personally seen the engineering plans, so I'm not 100% sure if it says anything in there about that. I didn't really ask my dad and I'm not sure if he's read all the way through the 15 pages of material, he just got the plans yesterday and has briefly looked over them. He does say that the tex is required every 3 tiers of blocks with this design and the drainage system is very well explained. I know this isn't rocket science, but having no experience with GeoTex poses a few questions to start with. So my question is, are there multiple methods for securing the GeoTex to the slope? And does anyone have experience with batter type blocks using the tex? Like I said, seems simple with vertical stack blocks and pins running vertically, but I'm not sure about the batter style and where to secure the tex to them.
     
  2. nac

    nac LawnSite Member
    Posts: 126

    I am assuming you mean geo-grid. You can have batter with Keystone block they have two set of holes for the pins. With a block with the lip just friction and the weigh of the block hold the geo-grid. The geo-grid is not attached to the slope it use the fill material above it to anchor it. The only time it is attached if it dos not have the room in distance then it is attached using rock bolt or soil nails around a steel pipe and back to the block. But if it is and engineered wall just look at the section threw and it will show everything.
     
  3. RockSet N' Grade

    RockSet N' Grade LawnSite Silver Member
    Posts: 2,454

    Scag......I just picked up a job like the one you are talking about. I am sure there are notes which are very specific about attachment and compaction and testing.....my little plans have all the specifics, fairly standard to include them. The real key to this process, is to get the engineer to commit to inspections on a timely manner of each phase of the installation and getting written approval from the engineer ( on each phase ) of the installation. That should be set in stone at a pre construction meeting......no if and or buts about it........if that is not included or discussed, a simple job could turn into a job that drags out 4-5 times longer than it should and it leaves you holding the bag entirely which is not what it is all about. I will say it again, because I have learned the hard way, make sure the engineer signs off in writing at each phase of install that is pre-agreed to before the job starts. Usually, inspections are not included in the bid price, and are paid in addition to the contract amount. Hope that helps......
     
  4. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Posts: 4,276

    I would also require the engineer too test the soil under the footer and have it verified stable before I would ad the base.
    It should be required but here only concrete footers get any sort of inspection so this is one area that is overlooked on smaller wall jobs.
     
  5. Scag48

    Scag48 LawnSite Fanatic
    Posts: 6,067

    Nac, that's kinda how I figured things would work with a block with a lip in the rear, just the weight of the block would hold it in there and I figured the same goes for attaching to the slope, the weight of the fill would hold it down unless you don't have enough distance to make the run. That's how I figured it should be done but thought I'd ask anyway.

    RSG, I will call my dad and have him get this all figured out. I told him to be cautious of anything that needs engineering, there are added steps that need to be carefully followed and you're absolutely right. I'm sure he's aware there is an added complexity of building an engineered wall to the extent of additional steps in the building process as well as covering your arse and making sure everything is done correctly through the construction process.
     
  6. Scag48

    Scag48 LawnSite Fanatic
    Posts: 6,067

    My edit time ran out. Just called my dad, forwarded some information from here to him and he understands the process he needs to go through. I told him he needs to sit down with the engineering firm and get an inspection schedule figured out and what that will cost. He said he might take pictures of the process as well to double verify that all aspects of the design requirements have been met or exceeded in the unlikely event of a failure down the road that would take the burden off the contractor's shoulders and back to the engineering firm. A guy in excavation I know had a wall engineered for a customer, built the wall to spec, it fell down. Went to the engineer, of course that didn't go well, he wasn't insured or something ridiculous, so they rebuilt the wall again. Fell down one more time, rebuilt it one more time and it's been good since, but the first couple times were a real hassle, the engineer was of no help.
     
  7. RockSet N' Grade

    RockSet N' Grade LawnSite Silver Member
    Posts: 2,454

    The job I just got like the one you are bidding on is for a bank. It is their engineer and I am doing it to his spec's and getting it signed off each step of the way. Another bug-a-boo you often run into is points of survey......I always make sure that I am not responsible for points of survey and it is an extra above and beyond bid price......they said on this one "they would help me layout lot lines", and I said NO!......I would have nothing to do with that.........don't get swindled into being responsible for that little nightmare waiting to happen!
     
  8. Scag48

    Scag48 LawnSite Fanatic
    Posts: 6,067

    Good call on the POS. I took a surveying course last fall at college, very informative. A lot of people start assuming and fumbling through lot lines, not a good plan whatsoever. That's one thing that can really bite you in the arse later down the road if anyone does any looking into about it.
     
  9. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    The old style way of doing it is using steel cable to dead mans buried behind the wall.

    What ever your dad does make sure the engineer has his or her name all over the plans etc. These engineers love trying to wiggle out of the line of fire when something goes wrong.
     

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