Hi, I'm in the process of looking for a mid-size rubber track excavator. In the meantime, I do own a Gehl CTL70 and was wondering if I bought the right attachments; maybe I can do without an excavator and just drill my piers with the Gehl. The piers are 18" in diameter and may need to go as deep as 20'. If I go this route, I'm sure I'll need extensions of some sort. Can anyone give me some ideas? Or if you've done this before, I would appreciate anything you'd like to share. Thanks
We used an auger a couple of years ago on a Cat 242, which is a rubber tired machine. It was for six holes, about 4-5 feet deep. They were for steel poles to support a sun shade thing at a community swimming pool. I'd never done it before, but it was pretty straightforward, and there were no major problems. The machine handled the attachment just fine, although, to go as deep as you're proposing would no doubt require stopping partway through and attaching more auger. That would really complicate things, as we found it advantageous to occasionally pull up out of the hole to shake the auger clean, to keep it maximally productive. This was in hard compacted fill, composed of slag from the steel mills, so there were all sorts of chunks of stuff in it. I don't know how it would've behaved differently in virgin earth. Interestingly, I wondered if Google Maps Streeview would show the completed structure, but apparently, if they'd been there just a day or two earlier, they might've gotten a picture of the drilling in progress! Here's the site, with the poles in place, but the shade not hung yet. Oh, and since this is your first post, welcome to Heavy Equipment Forums!
The only machine I have seen used for deep piering(over 12 feet down) was a lattice crane supporting a core drill rig, we have 'Texoma' rigs for deeper than normal post hole bores for tall utility poles but they fall short of the distance as they can only dig to around 12 feet while being quite heavy fully truck chassis mounted and cumbersome. Placing piers to a depth of 20' or more may be better left for pile driving or specialty companies due to the expense of the equipment for cut at depth.
Cat 299C Hi, First time on a forum but here goes We use a Cat 299C XPS track machine to drill all the time some 12" holes but mostly 16" our driller goes down to 33' max if u want pictures feel free to email me at [email protected]
Good luck using a skid steer to auger 18' deep holes. I have done many piers. To do such a deep pier you will need a long screw to help get the dirt up or you will be lifting and lowering a small bit a lot to clear the dirt each time removing and adding extensions. The above bit could be bound up if screwed in to far, if bound up the skid steer could not provide enough power on just 6' deep holes. I think I had to screw and lift about 10 times for holes in loose soil only 6' deep. I would think hiring a specialty rig would be best. Let me know how it works out. That is a new machine with just 60 hours on it.
done a lot of piers.....in our area with rocky soils and hard pans.....6' is about all you can do economically with a skid style machine....hard soils n rock will even make big drill rigs work for their pay.....and once you start having to add/take off extensions more problems arise and productivity is very poor...
The other option is to use something as the self drilling column piers as many of the foundation piering companies use. The units I know of come from AB Chance MFG, are basically 3" schedule 80 pipe with a drill flighting at the end, extension sections at around 9' are bolted onto the first 'bit' section and hydraulically rotated into the ground until 1) they hit solid and spin out or 2) torque the hydraulic motor clutch out. Helitech is the company that uses them here, only need a hydraulics supply system and the drive motor which could theoretically be mounted to a skid steer. http://www.abchance.com/wp-content/uploads/2012/07/01-9013.pdf http://www.abchance.com/products/helical-piles-anchors/
I've been 12 foot on 18 inch piers and saw a guy go 17 feet with a skidloader and auger. 12 is about the max that's easy unless you have the power head on a extended bobtach. If it stuck out like a three point hitch drill you would have the height plus sticking it down in the hole.