Hello, everyone.

This is Enta.

Do you know what this is?

 

That's right! These are the remains of the anchor material from the ground anchor work lol

I messed up lol

We had two failures on this job site.

 

What I learned from this experience was the mix ratio for grout used in grouting drilling.

Standard grouting drilling isStandard FormulaWe'll do it there.

In our case,

W/C = 50%, admixture 2%

8 bags of cement, 96 L of water, 4 L of admixture

That's right.

This method involves using grout as drilling fluid and injecting it around the casing while drilling in cases where the borehole walls in natural ground are prone to collapse or where sandy soil causes backflow after drilling.

Because cement slurry has a high specific gravity, this method prevents backflow; since it is injected into the rock mass, the borehole walls remain stable; and even when anchors are inserted, the grout reliably wraps around them.

Once the drilling is complete, you place a blind plug over the swivel’s discharge port and press it back in to prevent the grout from escaping.

If you move the machine up and down several times and grout comes out from the outside of the casing, I think the installation will generally go smoothly.

 

The water pressure at this job site was extremely high, so we used packers during construction.

However, it's not possible to drill a grout hole using a packer.

I can drill the hole, but with a standard cement mill, the cement starts setting the moment I insert the anchor—which uses a packer—into the casing!

In the anchoring industry,The packer is spinningThey say they'll do it.

 

If you dip a piece of cloth into highly concentrated cement slurry, the cloth absorbs the water from the slurry, and the area around the cloth hardens instantly. (It’s not very strong, but it’s in a firm, paste-like state.)

That's what happens inside the casing.

If that happens, the anchor, the packer, and the inner surface of the casing will become stuck together inside the casing and cannot be removed.

The result ends up like this lol

Since I'm completely stuck inside the casing with no way to move, I'm cutting through it with a sander to get the casing out lol

It's all a waste of time and money, lol.

 

Based on past experience, I knew that the standard formula wouldn't work.So, on this job site, we reduced the amount of cement. (Lean mix)

At first, I was mixing six bags at a time.

100 L of water and 6 bags (150 kg) of cement, without admixtures; W/C = 66%

We used this to perform a grouting borehole, and after inserting the anchor, we injected standard cement slurry into the packer.

Things were going well. (For a while, at least.)

But I realized later that it was super hot that day!!!

I suppose you could apply it even with a 6-bag mix, but even in winter, if you wait too long, it probably won't work. (High risk)

In the summer, it's only on rainy days or when the temperature is a bit lower. (Higher risk)

 

From then on, we switched to a batch of five bags.

100 L of water and 5 bags (125 kg) of cement, without admixtures; W/C = 80%

With this, we can definitely get the job done. (Low-cost mix)

We were able to ensure that the grout spread thoroughly around the casing without causing dehydration, and we were also able to significantly reduce backflow.

 

If you want to use a packer to stabilize the borehole wall and ensure the most reliable installation possible, this is one method you can try.

Of course, the process concludes with the injection of the standard mixture.

We use a lot of cement, but it's still reliable.

Considering the possibility that the ground anchors might come loose, I’d really like to use plenty of cement to build a solid foundation, lol.

I imagine each provider has its own way of doing things, but if you know of any other methods, please let me know.

 

See you later.