Hi Lately I have done a lot of small cut n fill's in backyards for retaining walls or creating a flat area on a slope. Am I doing this right? I approach the slope uphill and slowly cut in until I make a level pad back to the line where the wall will be. Once my pad is large enough to swing the skid around I then work my way across the slope low side first and take cuts until I get to the wall line. I am finding that as I work often i end up with the flat area draining back to the wall as if I have taken too much from the uphill side. Any ideas? I imagine my initial cut is too much as the bucket bites in? Would it be worth doing the pad and then putting the level on it before going further? Also my final cut to smooth off the wall, the side of the bucket is doing the cutting and i get flex through the arms and the bucket twists slightly. Is this okay or am I risking damage. I run a positrack RC30 which is used for narrow access jobs. Criticism's / Advice ? cheers dazzler
You're technique sounds similar to what I do. I start making a one bucket wide swath about 3-6" deep depending on the soil. Then I run with the arms down and use one side of the bucket to widen my original swath by 12-18" at a pass. With a little luck the dirt seems to roll right into the bucket, if the soil is good you can go at quite a clip. I try to keep the cut edge trimmed as I go using the side of the bucket with the arms fully lowered instead of trimming it at the end with a raised bucket. The only part about this that I think may be hard on the machine is the full width cut. I try to alternate sides when I am widening the original swath, the corner tooth on my bucket is more worn on one side since I seem to favor it. I always try to work with the arms fully lowered. It also helps to have a bucket as wide as your machine. I like working this way, because once you get a nice flat spot to work on it just seems to go so easily. If you don't have one you should consider getting a good laser transit or level. You can always set it up out of the way, and once establish a rough elevation you can run around with the receiver in your cup-holder and hold it up in the cab (you can tape a line in the cab a few tenths under), just to make sure you don't over-dig.
Sheer luxury :notworthy
Dazzler, we do retaining walls pretty much every week. To be honest we will use a skid if we can but probably 60% of our walls are cut with mini-excavator. This way we can be very precise with the width of the footing and don't move any excess spoil. If the wall is a big'un we do the rough dig with the mini-ex and finish with the skid. It also depends how much of the overburden is going to be used for backfilling the wall. Sometmes (if there is room somewhere) I will take 20-30 cubes out to a stockpile while the job is done. At other times we just have to lose some dirt in front of the wall by simply raising the level for the duration of the task. The best thing to do with your overburden is stockpile it behind the wall (if you can) so that its a simple manner of knocking it down for the backfill. This is where the mini-ex beats the skid because it has the reach to throw the dirt up behind the wall. We have the luxury of having two machines on site but many guys in my line just have one or the other and they get by with a little practice, some cunning and guile. All good retaining wall footings will have a very slight back slope...better to be slightly lower on the uphill side than vicki-verka.....nothing worse than trying to build your backslope into a wall that has a footing leaning forwards DAMHIK!. Also, you always need more space, and to take slightly more out of the back than what it appears. If I am prepping for a 720mm wide base I will always make sure I have a 100mm extra both sides. If I'm really trying to get the footing perfecto I will first over excavate with the mini-ex. Then I rough level low with the skid and compact with platey. Then I run in some clean yellow sand to bring it up and level with the skid, compact then finish with a box....thats what I do in clay or gravel footings.
sounds good