Hello, everyone.
This is Enta.
Starting this week, we have been drilling holes for ground anchors in Yamanashi Prefecture.
Since all the drilling machines normally used for anchors were already in use, this was our first time drilling with a spring drill.
The maximum drilling length is approximately 15 meters, and the borehole diameter is φ115.
I was totally anxious lol
I have experience drilling with a Spring Drill 40 II at a diameter of 90, but I have no experience drilling at a diameter of 115.
I was pretty nervous, but I managed to dig it up in a flash.
That said, when the surface gets hard, the speed drops off sharply.
How deep have you all drilled with the Spring Drill 40 II?
My longest direct excavation in sandy soil is 20 meters. (φ90 with grout injection)
Other than that, this 15m φ115 looks like it will be the longest one.
However, I figured that having a heavy casing would be a problem after all, so I’m using a slightly unconventional method for the installation.
A φ115 inner rod would normally be a 73 inner rod, but in this case, we're using a 57 inner rod.
Since this increases the bit play, I'm using the standard inner bit for the 73.
I'm using a reducer coupling for the 73-57 inner rod to connect the 73 starting rod to the 57 rod.
It's a strategy to lighten the machine's load, even just a little bit, lol.
The bit protrudes about 5 millimeters from the inner surface.
It probably depends on the soil conditions of the mountain, but for the water, we use a high-pressure washer in combination with compressed air (50 horsepower).
With these settings, we were able to drill a φ115–15m hole in about 2.5 hours.
However, if you don't secure the unit properly, it will move easily because it's lighter than the machine's power.
So, the front is secured with a lever block, and the back is secured with a steel pipe.
All things considered, it’s really handy that such a small machine can drill holes this deep.
Looks like I underestimated the power of the Spring Drill 40 II a bit, lol.
Large machines are convenient in their own way. They dig quickly and smoothly, and aren't too stressful to use, but they're just so heavy!
It's just so heavy!
That really sums it up, doesn't it? There are plenty of job sites where it's a hassle to bring things along.
Lightweight drilling machines are really handy, aren't they?
Machines have their pros and cons, so it's up to people to decide where to put them to work.
If you put them in a setting where they can make the most of their abilities, they’re sure to excel.
It all comes down to one approach to the operation, lol.
If the operators can work flexibly, the machines will surely respond in kind.
Since we'll be drilling through next week, it looks like I'll be commuting from Azumino City this week and next.
We're starting to hear a few mentions here and there about next year's work—how about you all?
See you later.
