This excavator appeared in Awesome Road Construction Part 2 and it's got one of the most unusual attachments I have ever seen. (Well, it looks like it's got the body of some unknown Hitachi excavator.) Do you know what this attachment is? And if yes, then is it still being manufactured and used today? Because these are the only screenshots I could make of it. Just look at the mess of hoses, wires and cables this attachment has! It was used to drill holes for rebars to make a highway retaining wall.
Looks like a drill to me Have worked around many pulling spoils from them at different sites.
Looks like a tie back blast hole drill mounted on a Hitachi. Appears to be a soil nail retaining wall under construction. Last year we were did the excavation portion of a similar wall for a new gas station.
This is what it's auger looks like:
Very crude mounting setup. Continuous flight auger. In that case I’d say stabilization of some sort based on auger size. We see them here doing geothermal stuff. Can’t say I’ve ever seen one mounted on the boom like that but I guess it gives them the angle needed. Bad thing about continuous flight is you can’t crowd on them very hard as there’s significant deflection. Makes sense in this case......if it’s soft enough to need stabilization odds are it’ll drill fairly easy.
I didn't spot the auger, good call. No that's not what the wall guys had on the project we worked on above.
There are some very similar rigs on the I5 project running through tacoma I haven't taken any pics but if I get a chance and traffic is lite next trip through there I'll try to get some if they are drilling.
Good good, cause I wanna see what these tie back drills look like today. And yes, the diameter of this auger's spyrolls are pretty small, so they didn't need a wide tunnel hole to install those skinny rebars. PS, here it is in action
Those images of DBM (Donald B Murphy) out of Federal Way WA (60 years and still drillin') are probably 35 years old. The carrier appears to be a Hitachi UH 122 probably mid 80's. I suspect that they are currently running gear that is consistent with the advances made in the industry. http://www.dbmcontractors.com/
Used ones similar to these in my early construction life as a pile driver. Drill them in, ram the DeweyDag bar inside the shaft, and then pump concrete grout down the inside of the drill filling the hole around the bar as you pull the augar out. Some have the capability of belling the bottom of the soil nail hole for additional support. They have not changed much over the years, just more user friendly and easier to mobilize now.