Hello, everyone.

This is Enta.

My senior has been in Nagoya for a two-night, three-day trip since the other day.

There’s a senior colleague from my old job whom I’ve been in touch with ever since I was 19, and,

For the past few years, I've been coming to Nagoya every year around this time for the general meeting of the construction methods association.

We've known each other for a long time, which is fun, but I end up getting dragged out to drink with them all night long...

I'll do my best tonight too lol

But that's beside the point.

Aren't units kind of a hassle?

Once you get used to it, it's no big deal, but,

I'm always forgetting things, lol.

Are there standard units used by slope engineers?

So, let's take a look at some units that can be confusing.

Tensile force used in anchor work

MPa (megapascal) = kgf/cm²

To put it another way, if I want to apply a pressure of 1 metric ton, do I just apply a tensile force of XX MPa?

Let's break down kgf/cm².

kgf refers to pressure.

"cm²" refers to the area under pressure.

So, the pressure-bearing area refers to the surface against which the jack presses.

This is a cross-section of the top part.

The red area corresponds to the pressure-receiving area, and you divide by that area.

That makes it an SI unit called MPa.

Please remember this one thing.

1 kgf/cm² × 0.0980665 = 0.0980665 MPa
1 MPa = 10.2 kgf
1 kN = 102.0 kgf

For example, Fujiwara Industries' 1,000 kN model

Let's say you used a center-hole jack.
(FSC Fujiwara Industry Data)

The pressure-receiving area is 150.8 cm².

We will apply a load of 100 kN.

100 kN equals 10,200 kg, or 10.2 metric tons.

MPa = 10,200 fkg/150.8 cm²
67.6 kgf/cm² × 0.0980665 = 6.63 MPa

Recently, jack calibration tables have also been converted to SI units.

So, there's no need to worry about it too much, but,

It might come in handy to know this just in case.

See you later.