Hello, everyone.
This is Enta.
先日の九州ではだいぶ涼しくなっており、あれ？秋？？
って思うほどでした。
昨年の灼熱地獄を思えば昨年はホント異常気象でしたね！
楽年に比べて体が楽なので良いです。
But that's beside the point.
Points to Consider When Choosing Self-Drilling Screws
There are quite a few reasons to choose self-drilling rock bolts, aren't there?
The key selling point of this self-drilling rock bolt is that it can be drilled even if the borehole wall is not self-supporting.
However, this actually caused a problem in the past.
Self-drilling rock bolts look something like this, right?
(Please ignore the image preview.)
Self-drilling rock bolts can generally be drilled into most surfaces.
Even if the borehole wall keeps collapsing, it’s easy to drill down to the specified depth into the bedrock.
On the other hand, if the excavated soil is not being discharged, the cement slurry injection will stop at the tip.
The key to drilling with self-drilling rock bolts is to drill while ensuring the borehole walls remain stable.What's up with that! lol
I'm saying something weird, aren't I?
Realistically speaking, to remove the drill cuttings, you have to clean thoroughly as you go.
To do this, we repeatedly move the steel beams in and out to remove the soil.
そしてロックボルトを予定の箇所にセット出来るんです。
There is no other way to ensure that the grout is injected into the self-drilling rock bolts!!!
That said, there is one method: drilling a double-pipe borehole and installing self-drilling rock bolts...
Any rock bolt into which cement slurry cannot be reliably injected is considered a defective installation.
It was a human error during construction.
The most important factor to consider when selecting and installing self-drilling rock bolts is
1. Is it possible to reliably inject the cement slurry?
2. Is it possible to apply the cement slurry so that it completely coats the steel?
3. Does the design have a diameter that allows for circumferential friction?
*Note: Even if the cement slurry is partially displaced by soil, there is a very real possibility that the circumferential friction will not be lost.
Please take that into consideration when reviewing the matter.
機械が入らないから自穿孔でって言う選択肢は十分あります！
See you later.
