Automated Vane Shear ( AVS )

Owned by jr_pinero
Last updated: Mar 26, 2024 by jr_avila
6 min read

X402

  • AVS tested, not used. all good

X400

  • AVS was only used to measure five points at the first site. It was no longer used by scientists after that.

  • No issue is reported.

X395

  • AVS has been tested at the beginning of the expedition, no issues

  • Not used on X395

X399

Not tested and not used on X399.

X398

AVS

Software Issues

  • At the beginning of the expedition GeoLab was not opening properly, the Init button didn't appeared in the window. The GeoLab folder on the computer had a lack of information. The old GeoLab from the TRANSFER folder was copied to the computer and it worked properly. 

  • Scientists asked to add to the database a value of 150 kN/m2 for sections with harder material than the one that could be measured with vane A.

 

Penetrometer

  • Scientists used the penetrometer to measure in the bottom of each core during the APC coring, measurements were taken parallel to the core in the z-direction.

  • Data were uploaded to LIMS using SpreadUploader because  Shear_Penetration Strength Uploader has not the ability to manage these measurements. 

  • Related with the previous point and after having talk with the developer in charge (David Fackler) a new uploader spreadsheet will be developed to allow the scientists to upload penetrometer data in a more efficient way. The changes that will be incorporated are:

    • Under adaptor there will be for options: One for the penetrometer without adaptor and the others for the three adaptors that we have onboard. Each of these last three ones will make the appropriate correction using the correction factor written in the adaptor. Currently only the non adaptor and the foot-adaptor options are available in the spread sheet.

    • Allow to insert the Text ID for sections. Currently is only possible to enter, by scanning the label, the Text ID of section halves.

    • Allowing to enter the Text ID manually or using a drop down menu, like in IMS. Currently is only possible to enter it by scanning the label.

    • Prepare the software to bring together with the text ID also the length of the section and allow the user to select if the measurement has been done in the bottom or in the top of the section. Currently is only possible to enter the offset manually.

  • It is not possible to change the actual Shear_Penetration Strength Uploader because it is protected by an unknown password.

  • To compare penetrometer results with AVS measurement scientists followed the procedure bellow:

Results obtained with the AVS are reported in kN/m2 and results reported by the penetrometer (compressive strength - Δσ) are in kg/cm2. 

To compare both results scientists converted the penetrometer results using the equations: Δσf (kPa) = 98.1 x Δσ(kg/cm2) and 1kN/m2 = 1000 Pa

Using Peter Blum 1997 Technical Notes: Unconfined shear strength (Su(penet)) is approximately related to compressive strength using Su(penet)= Δσf/2

 

X397

  • Not Used in this expedition.

X397T

  • No shear strength measurements were taken.

 

X397P

  • The software had the known communication issue, preventing the INIT button from appearing at start up.  After restarting and reconnecting cables, the software worked properly.

  • The AVS master spreadsheet was corrupted during the computer transfer, but another copy was found and placed on the computer.

X393

  • No issues reported during this expedition.

X390

  • Some AVS measurements has made in soft sediment corers

  • No issues has reported in this expedition

X392

  • Not used

X391

  • lost communication with pc, disappearing the ini button. solution: restart the pc, disconnecting the 232 communication cable

  • Soft sediments were tested on Automated Vane Share but the AVS lost communication with the PC. The RS232 to USB cable was replaced with an RS232 to RS232 cable. This solved part of the issue, but periodic issues continued to occur and were resolved by shutting down the PC and unplugging the 232-communication cable and then plugging it back in and starting again.

X396T

  • Not used

X396

  • Not used

X395C

  • Not used

X395E

  • Not used

X395P

Mar 7, 2021  Torvane and Penetrometer QSG was reviewed and updated in Confluence.

X390R

  • QSG were reviewed and formatted.

Tests

  • We carried out tests where the sensitivity of the instrument is measured in response to different known loads, arranged in various configurations, explained in the, Automated Vane Shear (AVS) Test  Report (*.pdf), attached in Technical Notes section on this page.

The experiment is designed around a pully system, where a weight is suspended from a thin cable, over a single or double pully, then attached to special vane fixed to the AVS.  Using this setup, a torque is measured and compared to calculated theoretical values.

Fig1 support of pulley system and vane to perform torque test

 

The result of test applied is divided in five groups, one for each distance in the vane using the same weight, the last experiment was using an additional weight (50g) using single and double pulley.

In the configuration n.5 we use 161g of weight (0.06Nm) with good results in accuracy and precision, and this correspond near to half torque of an average of the torque measured in an historic data (X353 to X375), corresponding to 0.19016Nm.

 

Report is under review by David Houpt, Gary Acton and others on shore.  The plan is to have the Lab Working Group review the report and make recommendations on keeping the current setup and using the pulley method to calibrate, or getting a new AVS, or just using the hand held Torvane.

X390C

  • This station was not used during the expedition.

  • Tests will be perform while in port during next expedition.

X390P II

  • Not used during this expedition.

X384/390P I

  • No used during this expedition.

X387P/387T

  • The AVS station was not tested since last expedition.

X378/378S

  • Jan 3, 2020toJan 11, 2020

    • A little metal piece of metal was founded down the drill apparently broken from the left side of the axis (fig1)

 

Fig 1

The metal part was delivered to the marine instrumentation specialist to find the spare part.

AVS was tested without the spare part and presents data consistency in 10 consecutive tests (table 1).

 

AVS KN/m2

offset, cm from top

43.821

20.5

52.911

18.5

50.5

16

46.152

14.5

50.814

12.5

49.881

20.5

48.949

19

49.881

17.5

48.25

15.5

49.182

13.5

  • We have put "the screw back in the screw", unfortunately the tests carried out are not consistent with the old measurements, we try to adjust the position of the 3 points of contact with the sensors but the measurements are still different (lower, around 20-30 KN/m2) to the old ones.

  • Jan 10, 2020 GeoLAB did not have "init" button to start testing: When opening GeoLAB software, the "init" button in Figure 2. in the user guide did not show up. It was suspected that there was an hardware connection issue between the instrument and the computer. This was resolved by turning both the instrument and computer off and disconnecting the R232 to USB cable. Then after 30 seconds connecting the cable again and first switching the instrument back on followed by the PC. When opening the software the device was now connected with the init button appearing on screen.

X378T

No Issues

X385

  • Sep 23, 2019GeoLAB did not have "init" button to start testing: When opening GeoLAB software, the "init" button in Figure 2. in the user guide did not show up. It was suspected that there was an hardware connection issue between the instrument and the computer. This was resolved by replacing the serial-port-to-serial-port cable which was linking the two machines by a new serial-port-to-USB-port cable. Upon installation, the "init' button came back and the software has run smoothly.

X379T/385T

No Issues

X383

No Issues

X382

No Issues

X379

No Issues

X368T

No Issues

X378P/368X

No Issues