Hello, everyone
This is Enta.
I was in the Kanto region starting last Thursday.
I visited one of our group companies' sites to conduct an on-site inspection and determine various courses of action.
It was a tough job site, so I had to figure out a better way to do things—just checking in lol
With challenging projects, the initial approach is crucial, so I intend to handle them thoroughly.
But that's beside the point.
This is a continuation of my previous post.
4. Tension Work
If there are any mistakes from this point on, they’re more likely to be on the construction management side.
A significant number of managers have the wrong idea about stress management, but,
Td × 1.25, based on the design anchor force for Grade A
The maximum test load is set so as not to exceed this value.
It's okay not to exceed that amount. However, most people calculate using 1.25 times that amount.
Japanese is difficult, but,
"Go Beyond"＝"Excluding the reference quantity, it must be greater than that amount."
"Don't go over"＝"Not including the reference quantity, but being less than that"
Based on the interpretation above, that means the maximum load is 1.24 times the standard load. (Not that it really matters, lol.)
Well, I guess you could call it nitpicking, but dealing with someone who’s that picky would probably get annoying at this point, lol.
Inspectors who nitpick every little detail, lol
But that's not actually the point.
The part where there's a misunderstanding is,
Tests are conducted at 1.25 times the standard load for all soil typesThat's it.
If the anchorage is in rock that's as hard as a rock, then sure, that would be fine.
But what if it’s a slimy mudstone that’s hard to drill through when water gets in?
No matter how long the hold is, I think it’s a bit much, and you’d probably want something a little lighter, right?
It's okay to use that feeling as a benchmark, right?
This means you don't have to apply a load equal to 1.25 times the maximum test load at every anchor site!
"The maximum design load specified in the standards is an upper limit; since testing is conducted using anchors that will actually be used in service, the responsible engineer may, based on the actual conditions at the site, set the load below this limit."
Design and Construction Standards for Ground Anchors, and Commentary Thereon, p. 190, Japanese Geotechnical Society
That's what it says.
There’s no need to subject something that will be in service for decades to such rigorous testing.
Simply put,As long as it can withstand loads greater than the design load, that's fine.That's the point.
Personally, I interpret it as meaning that the design load is sufficient, lol.
However, considering set loss, it’s best to keep it between about 1.10x and 1.20x.
In my case, I use the same safety factor for both the qualification test and the verification test, so the maximum test load is the same.
It makes writing on the blackboard easier, lol (though we use a digital whiteboard now).
I actually use a multiplier of 1.15 to 1.2 times (to ensure it exceeds the set loss).
Even if you submit a contingency plan to the government office, they usually won’t say anything, and if they do ask why,
The mountain was rough, so I played it safe. I'll just go through here.
Since the government office will be using it later as well, I’m not saying you absolutely have to pull it.
Outsourcing construction management seems like a bit of a hassle, but let's push through with it.
(You wouldn't want to be told what to do by a construction manager who has neither the authority nor the knowledge, would you?) lol
These are the areas where construction errors can occur when using anchor bolts.
What do you all think?
See you later.
The Moment the Anchor Breaks Free!
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