In situ vane shear test
In situ vane shear test
(OP)
Hello,
I am trying to become familiar with this in situ test since a client is requesting this for a project.
After doing some research, I noticed that the stores that sale the apparatus (blades + rods + etc), they only sale a total rod length of 3 meters (6 pieces of 0.5 m).
Is this test meant to be performed in the top 3 meters (10 ft) below surface?. I have watched few videos and usually they run the test in the top 2 to 3 m.
In this project, I foresee soft clays at 15 and 20 mt below surface. Is there any special way to perform this test at these depths?. I am not sure if by adding more rods will be enough to run the test at these depths. I noticed the rods are too thin and at these depths they might buckle.
Please advise.
Thanks.
I am trying to become familiar with this in situ test since a client is requesting this for a project.
After doing some research, I noticed that the stores that sale the apparatus (blades + rods + etc), they only sale a total rod length of 3 meters (6 pieces of 0.5 m).
Is this test meant to be performed in the top 3 meters (10 ft) below surface?. I have watched few videos and usually they run the test in the top 2 to 3 m.
In this project, I foresee soft clays at 15 and 20 mt below surface. Is there any special way to perform this test at these depths?. I am not sure if by adding more rods will be enough to run the test at these depths. I noticed the rods are too thin and at these depths they might buckle.
Please advise.
Thanks.
RE: In situ vane shear test
RE: In situ vane shear test
At 15 m, how did you measure torque?, I ask that because 15 m is a long AWJ rod length, so i am not sure if applying torque from surface will require a special correction to whatever torque value you read at surface.
RE: In situ vane shear test
RE: In situ vane shear test
Yes, sometimes they can only reach to 5 or 10 feet in depth.
Sometimes the soft clay is located at 20 feet in depth which renders your equipment null and void.
Bear in min the cost comes out of your pocket and you may only use it 5 times.
Why not just ask the drillers if they have a vane?
I assume your going to hire a driller?
Many drill companies have vanes that can be put on the end of AW/AWJ/NWJ rods.
Vanes usually come in a variety of sizes for different soil stiffness.
Use some casing and then you can eliminate all the rod friction error issues.
As BigH noted - in the 70's and 80 we used a fish scale which was the best tool at the time.
Most drillers now have fancy calibrated torque wrench's that they carry on the drill that can be used to turn the rods and complete the test.
Check with your local drillers.
RE: In situ vane shear test
We had a pilcon shear vane that attached to the pipes also. We would do hand augers in SILT/CLAY down to 6m depth. The only reason we didnt do deeper was because it was difficult to pull 6m of pipe out of the hole, lay it down, take the soil out and put it back in the hole. Up to 4m generally 1 guy could manage but it was a 2man job after that.
RE: In situ vane shear test
RE: In situ vane shear test
RE: In situ vane shear test
RE: In situ vane shear test
RE: In situ vane shear test
So if you have 2 lengths it's 1.9m, 3 is 2.8, 4 is 3.7m, 5 is 4.6m, etc