Hello, everyone.

This is Enta.

Lately, there have been a lot of rebar insertion jobs.

The contractor told me, "There aren't many ground anchors, are there?"

Well, the fact that there’s no ground anchor work means they’re not expecting a major landslide—and they don’t want to spend that much money on it, right!?

I can't really say anything about this area, though, since there's a lot of mutual back-scratching going on between the government office and the construction consultants, lol.

Is the government out of money, or have they already done everything they can?? lol

Some of you may not know this, but,

As a general rule, the maximum length for rebar insertion is 6 meters.

The minimum length for ground anchor work is 7 meters.

For ground anchor construction, the minimum anchorage length is 3 meters, right?

Therefore, since the minimum free length is 4 m, 3 m + 4 m = 7 m.

If stability calculations show that the required retaining force cannot be maintained using the rebar insertion method (i.e., the retaining force is insufficient), the method will be changed to the ground anchor method.

To put it in extreme terms, it’s like using a single ground anchor to support a structure that would normally require five rebar inserts.

You can then decide between the two by considering factors such as cost-effectiveness, workability, and economic efficiency.

That's the general idea.

Every now and then, JR in Tokyo does seismic retrofitting work that involves inserting 7-meter-long rebar, lol.

It’s a bit unusual, but since standard rebar isn’t strong enough for that kind of application, we sometimes use PC strands called “Genbi Stabs.”

Since this is a construction method that’s quite rare these days (or perhaps outdated?), it’s believed to be almost nonexistent now. (JR might still use it, though.)

Here's what the distinction between rebar insertion work and ground anchor work looks like.

Reinforcing bar insertion work is limited to 6 meters

Ground anchor work starts at 7 meters

Please keep that in mind.

Theoretically, there's nothing you can't do, lol.

This is left up to the designer's philosophy. (Looking at the old design documents...)

See you later.