Site remidiation

Discussion in 'Landscape Architecture and Design' started by activelandscaping, Nov 23, 2004.

  1. activelandscaping

    activelandscaping LawnSite Member
    Messages: 241

    I was wondering what process you would use to remedy the following. This is a retention pond in a high visibility area and the original prints called for Rip-rap flumes to be constructed. However, they wanted something that looked nice and directed that the flumes be cobble. There is no responsibility on the part of the installer, no it wasn't me , to remedy this since deviation from architectural spec. was properly authorized. The before pics are what you see, geo-fabric and 6" cobble turned to s**t. What you see in the after pics appears to be a cobble flume, in fact only the top layer is cobble. I will list the site specifics. How would you address this problem?

    (1) Soil- Muck( at least 3' deep ), incapable of any load support, especially in the flume discharge and spillway area.
    (2) 14" and 16" concrete discharge flumes coming out of clean 36" sumps.
    (3) These discharge 20 acres of storm runoff into the pond, 15 acres is roof or parking lot, while not quite fire hose velocity there will be a lot of hydraulic pressure directed at the flumes.
    (4) You have 10 days to finish the job. They want it done in time for a major project launch, all their customers will be attending.
    (5) You have an open ended PO from a 200 million dollar/yr company. This is the only time I have ever received an open ended PO, those of you who do commercial work know what this means.

    I will list the remedy I provide later. I video taped the actual work, I will try and pull some stills off the tape. There are some more pics on the Best work thread.

    The original install is less than a year old and the owners still want it to look like cobble or a nice stone finish.






  2. D Felix

    D Felix LawnSite Bronze Member
    Messages: 1,898

    I'm doing a lot of catching up here, acording to the calendar (girls) thread, this is the first time I've been here in 10 days.:D I'm surprised no one else has answered yet....

    Even though I've never had to deal with anything like that, here's some of my thoughts:
    -Bigger pipes are needed. The bigger the pipe, the slower the velocity.
    -Bigger pipes mean bigger channels, d'uh.:)
    -Excavate the channels past muck depth, down to hardpan. The fill with either concrete, or, probably more preferably, large boulders at least 2'x2'x2' in size. Gradually build up to finish grade by filling voids between boulders with small stones, and build on top of that with smaller 6-10" stones. Again, fill voids with smaller stones and finish off with smaller stone.

    With an open ended PO (I assume that to be basically a blank check?), it could be done in 10 days assuming the weather doesn't turn to complete sh*t. It could probably be done in 5-7 if the weather is good, i.e.- no rain. Rain would probably add a day or two, but work would still be attempted on rainy days.

    Is that 10 days from the time you look at it initially? Or 10 days start to finish? If the former, I can't imagine the stress level! It could be done, and there better be a blank check!!

    Equipment that I would forsee: Tracked skidsteer (Bobcat T300 or equivalent), larger track hoe ~14-18 ton, possibly a mini-ex (Bobcat 337 or larger equivalent). Not to mention the trucks or any really specialized equipment that might be needed....

    So how'd you do it?

  3. activelandscaping

    activelandscaping LawnSite Member
    Messages: 241

    D Felix,

    Unfortunately it was 10 days from the time I looked at it. I was called on a Tuesday afternoon and got the OK the next morning. To be honest I didn't even want the job, but they had given me quite a bit of work and I couldn't figure out how to say no and still expect more work from them. I flat out refused to even give them a ballpark figure, and was in shock for about 10 minutes after I got the OK. :eek:

    The storm drains are laid in 10' solid sections. There wouldn't be any way to get the sections out without breaking up the road. To be honest the velocity coming out of the flume wasn't really as much of a issue as the volume running down the grade.

    We caught one break on the job, we were able to cart the spoils across the road to some vacant land they owned.

    The way you described was pretty close to how I ended up doing it.
    The tough part on this job was removing a bucketful of muck, without having the rest settle in. I ended up taking a bucketful of stone, then forcing the bucket down into the muck and displacing it with stone. I kept doing this until I had, essentially, built coffer dams 20' out ( around ) the perimeter of the flume/spillway area. This was the only way to prevent the muck from resettling.
    I mucked out about 250 yd of wet material. It was roughly the consistency of loose pudding. This was the worst stuff I ever worked with, by the end of the day everything & everyone on the job was covered. We replaced the crap with 6" crushed concrete, compacted in 12"-24" lifts. The flumes themselves are actually constructed out of Geo-web. The web was pinned, and spread open, using 42" re-bar (driven down into the crushed concrete). I used a pumper truck to fill the web with 2000 psi concrete and we then seeded the concrete with the stone cobble.

    I used a Komatsu PC300 LC-6, 60" bucket & 60' extended reach. Cat D5N wide-track, which immediately got stuck and cost $ 450 to get pulled out. A 15 yd aluminum dump. I also had a ASV on site.
    The only part of the job I let out was laying the sod. We did all the prep. but after 8 straight days, non-stop, I just couldn't stand the thought of a semi full of sod to lay.

    We managed to finish up on Wednesday afternoon and they laid the sod Thursday morning, the kickoff party was on Friday ( I gave everyone the day off with pay ).The only last minute hiccup I ran into was the SOB who brought the 40 yd dumpster never showed up to get it. I borrowed a 50 ton forklift from the plant and dragged it into the back, where no one could see it. The job total ended up at around 80K, not bad for 9 day's worth of work.:D

    Thanks for the reply D Felix. I believe your solution would have worked just as well. :)


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