Hello, everyone.
This is Enta.
The other day, I asked our "Legend" (age 74), "How long are you going to keep working?" (meaning, "How many more years or so?")
When I asked about that,
"Every day is a battle!"
I was speechless at the words of that veteran figure....
But that's beside the point.
It’s really tough when the sand keeps washing back—what can be done about it?
1. Increase the water flow. (Use a larger machine.)
2. Upgrade the compressor.
3. Don't overdo it with the digging.
4. It's also important to wait until the sand settles.
5. I'll start writing now.
This time, we used grout!
Typically, once the double-pipe drilling is complete, the inner casing is retrieved and the anchor body is installed.
However, this time there was so much sand being kicked up that,We injected grout from the tip of the inner casing.
Next is the retrieval of the inner casing.
It looks like they sealed off the inside of the casing with grout first.
The specific gravity of cement slurry is 3.0 or higher.Since it’s more than three times heavier than water, it doesn’t rise to the surface easily.
If the water level is too high or there is water pressure, even that might get blown away, but in that case, other measures would be necessary.
When I injected the grout first, it stopped bubbling up.
Thanks to that, it took hold successfully this time.
I'm sure some people will say, "That's not the right way to do it!" but it worked for me this time.
As expected, it has taken root firmly.
There are some drawbacks to this method.
There's a tremendous amount of resistance when inserting the anchor body.
"Resistance" means that since it's inserted into the grout, it doesn't go in easily! It's also called "dip-coating," but it's a real struggle because it's so hard to get it in.
Plus, grout gets everywhere—from the inner casing all the way to the machine's water supply line—so it's a pain to clean! lol
It can't be helped, but grout always seems like it could be washed off, yet it just stays there, doesn't it?
Wash it thoroughly and get it ready for next time, lol.
Actually, grout loses moisture very quickly when mixed with sand.
That's why the surface of the grout is rock-hard after injection. (Applying pressure to the sand is extremely effective.)
I suppose it would harden completely even before the grout is pressurized by its own weight, though.
Therefore, using the method described above allows for installation while ensuring sufficient anchorage.
In some cases, the water pressure can be high. When the water pressure is high, the grout gets pushed out!
I’ve only experienced that once myself. Man, was I panicked! lol
You’re probably wondering, “What do you do in a situation like that?”
I'll save that for next time, lol.
See you later.
