retaining wall layout tips

Discussion in 'Landscape Architecture and Design' started by smithsonmi, Aug 31, 2000.

  1. smithsonmi

    smithsonmi LawnSite Member
    Posts: 75

    I completely understand the nuts and bolts of this installation, but would appreciate some tips. The 4' wall I will be working on extends out from the house at the bottom of a hill and after 10 feet or so it curves up the hill at a constant radius (the minimum radius the wall can make without cutting...) and then continues another 10 feet or so at that angle (the radius is basically a fillet between the two walls). Since this is on a hill, what is the best method to layout this radius? If it was on level ground, it would be a simple metal post at the center with string etc.. but since the ground at the center of this curve is 4 feet higher than the base course, how should I measure out this curve?

    I considered making a template from a large piece of cardboard. or....suspending a level measuring tape and hanging a plumb bob?

    Thanks!
     
  2. steveair

    steveair LawnSite Bronze Member
    Posts: 1,073

    I would just 'eye' it out, but if you really don't feel comfortable doing that I would try to do the string/radius idea, hanging a plumb bob from the end of the string.

    Now, just a tip.

    Because wall block usually has a set back (at least in most cases) what this means is that if the wall is going to step into the hill during the turn, then the wall WILL NOT be perfectly strait, at least technically, and marking it out really does not help. You can "float" them a little if you need the wall to run perfectly straight, but it sounds like you won't have to worry about this. Usually a problem if the wall is stepping up along a straight drive or what not.

    What this means is that, if the wall is 4 ft tall (by the way, don't go much higher, as you should have it engineered then) then the block at the end of the wall after the turn will be 8" (4 ft wall = 8 6" blocks) inches father in (if there is a 1 inch set back on the block) than the first block at the bottom of the turn.

    Hard to explain, so maybe someone else can explain it better than me if you don't quite see it.

    o, I think the best idea is to just 'eye' it. Just concentrate. Be the wall.......

    steveair
     
  3. paul

    paul Lawnsite Addict
    Posts: 1,625

    Steveair:
    sounds right too me :)

    Just wondering 48" wall plus how many block buried?
    I would bury at least one block depending on the surcharge and might even install grid along with it.
     
  4. BRL

    BRL LawnSite Bronze Member
    Posts: 1,211

    Steve,
    You made me laugh. "Be the wall" It works. I've gotten strange looks & good laughs from customers while "being the wall" during planning or designing stuff. But it works sometimes. ;)
     
  5. FIREMAN

    FIREMAN LawnSite Senior Member
    from n.j.
    Posts: 318

    CONSIDER A TRANSIT, GET A HELPER AND DO ALL THE MEASURING WITH A TRANSIT, IT'S A REAL PAIN IN THE A** TO FIGURE OUT THE FIRST FEW TIMES BUT IF YOU READ IT RIGHT IT'LL NEVER BE WRONG. THATS IF I AM SEEING THE SAME THING IN MY HEAD AS YOU ARE WITH YOUR EYES, HOPE THIS IDEA HELPS.
     
  6. smithsonmi

    smithsonmi LawnSite Member
    Posts: 75

    Thanks.

    First, I am using Lafarge's Cambrian wall...it allows 4' walls (including buried...6") with standard block or up to 6' with their extended blocks without grid.

    I am going to try either the transit or plumb bob method as this wall is meeting up with another wall coming down the hill (two terraces meeting in the middle....). Plus I am using the minimum radius to reduce cutting, but that is the TOP of the wall...I have to add 3/8"/row for setback to get the radius for the base row and I would like that to be very exact so I reduce the cutting of the caps since I have that design flexiblity.

    I can see the wall now.....ahhhhh
     
  7. steveair

    steveair LawnSite Bronze Member
    Posts: 1,073

    Hello,

    A quick note on terracing walls.

    Not sure how you are terracing, but will say that you need to be careful.

    For example, from a engineering standpoint, if you are going to build a 4 ft wall first and then have another wall behind it, say set back 4 ft, and that wall is 3 ft tall, then from a technical pt, the engineering should be considered as 1 wall at 7 feet. What this means is fabric would be suggested.

    I say this because a case that happens is this. I have seen a situation where a builder, who knew he needed a engineer to build anything over 4 ft, needed to build a 20+ wall for a new housing development. So, to bypass the engineering, he built like 7 tiers, all less than 4 ft, none with fabric, no engineering.

    What happened is, after two years, the walls failed and a condo slid down the hill. Major problems there.

    Now granted, for a most tiered walls, especially of the scale you are doing, not a concern, but it is something you need to keep in mind.

    steveair
     
  8. smithsonmi

    smithsonmi LawnSite Member
    Posts: 75

    Great advice.

    Both walls will be 4' with 20' between them...Ok?
     
  9. paul

    paul Lawnsite Addict
    Posts: 1,625

    that should be no problem.
    Surcharge on slope should be ok but still think about grid

    [Edited by paul on 09-03-2000 at 01:59 PM]
     
  10. mattingly

    mattingly LawnSite Member
    Posts: 136

    guys,
    I am having trouble visualizing all of this and want to get into more wall building. People love this sort of thing around here. Do any of you have books you have looked at initially to help you out. I know lots probably learned via experience but i would like to read up on it. Any suggestions?
    TIA
     

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