Hello, everyone.
This is Enta.
Clamping force
How much torque do you use to tighten rock bolt nuts?
As a general rule, it is considered standard to tighten it just enough so that it does not come loose.
You aren't tightening the fasteners based on the tensile load Td specified in the design phase, are you?
Please don't do that.
There is a possibility that the soil and cement slurry may become detached.
However, there are cases where the tightening torque is lower than the point at which the Td is too low to loosen the fastener, but
In that case, please make sure it doesn't come loose.
Is there really no way to loosen it at all?
Actually, it comes loose pretty easily.
When it's tightened like that, it won't budge an inch with just your bare hands.
So, how do you loosen it up? Well...
I think the nut is tightened and the bolt is sticking out slightly.
Try hitting that head with a hammer.
The red partThat's it.
To put it simply,The friction in the screw is dissipated by vibration.That's right.
I can just hear someone saying, “Well, then don’t hit it!”
The end treatments on rebar inserts along expressways and other major roads are quite loose.
You might occasionally find them lying along the main road.
The reason for this is the vibration caused by the car while it's moving, isn't it?
This vibration is actually quite powerful, so it can actually loosen the screws.
So, next time we'll look at countermeasures.
See you later.
