Introduction

The AVS test is used for in situ determination of the undrained strength of intact, fully saturated clays (undrained strengths < 100 kN/m2); the test is not suitable for other types of soil or if the clay contains sand or silt laminations.

A four-bladed vane is inserted into the split core and rotated at a constant rate to determine the torque required to cause a cylindrical surface (with a diameter equal to the overall width of the vane) to be sheared by the vane. This destructive measurement is done in the working half, with the rotation axis parallel to the bedding plane. The torque required to shear the sediment along the vertical and horizontal edges of the vane is a relatively direct measure of the shear strength. Typical sampling rates are one section per core until the sediment becomes too firm for insertion of the vane.

The rate of rotation of the vane should be within the range of 6°–12°/min.

The GeoLab software that controls the AVS calculates shear stress as:

Stress (kN/m2) = torque (Nm) × Vane constant (1/m3) × 1/1000

Procedures

Preparing the Instrument

1. Click on the GeoLab Icon on the Desktop to start the GeoLAB application (Figure 1).

Figure 1. GeoLab Icon.

2. Start a new project for each site: Project > new > project > Expedition_SiteHole (Figure 2).

3. Start a new test in the project folder: Project > new > test > CoreTypeSection_Offset or TextID_Offset.

4. Keep the subdirectory highlighted, and click on EXCEL from within the application (Figure 2).

Figure 2. New Project.

5. Select the Excel template (e.g., AVS_master_XXXX.xls) (Figure 3). The PP technician will select and save a master file for each particular expedition.

Figure 3. Excel Templates.

6. Check the rotation speed (1–1.5) and vane type (A, drop-down list) (Figure 4).

Figure 4. Rotation Speed and Vane Type.

Making a Measurement

1. Insert the vane into the sediment, by turning the black handle clockwise, until the top of the wings are even with the sediment surface. Avoid obviously disturbed areas (cracks, gaps, bioturbation, etc.) and note that the test is not suitable for sand or gravel-sized material or for clay that contains sand or silt laminations.
IMPORTANT! If the brass fitting (Figure 5) pushes out of the support beam below the hand crank, the sediment is too hard for this test. Do not attempt to force the vane into the sediment as you may damage the instrument!

Figure 5. Brass fitting

2. Open the Excel spreadsheet from within GeoLAB by clicking on the Excel icon (Figure 2) (Points 3 to 6 on the previous paragraph).

3. Use the barcode gun to scan the section information into the yellow cell below the graph. Be sure to cut everything past the textID (e.g., TEST-U341PA…) and paste into an adjacent cell (Figure 7).

Figure 6. Monitor Acquisition.

4. Measure and enter the offset from top of section (blue cap) into the top interval field (light blue box), then click Enter.

Figure 7. Paste Barcode TEXT_ID (make sure to segregate the TEXT_ID and Label_ID so it will upload properly).

5. Modify this information for each core measured.

6. With GeoLAB already open, Click on init; set sample-time to 1 to 3 readings/sec (i.e., sampling rate), depending have often a measurement will be taken (Ex: 1 sec. means that a measurement each second.; and click the traffic light icon to start the measurement (Figure 8a). Set Input Speed to 1. Monitor the test curve on the Excel screen (Figure 6). When the maximum shear strength of the sediment (highest point of the curve) has been reached, stop the test by clicking the STOP sign icon in the GeoLAB application (Figure 8b).

Figure 8a. Set Acquisition Parameters. Figure 8b (click stop sign after the measurement).

7.Copy the Text_ID from the Excel page.

8. Save the Excel template with its data as a .CSV (comma delimited) file using Save As…CSV UTF-8 (Comma delimited) (*.csv) : Path = C:\data\gantry\in; Filename = TextID_offset_AVS.csv

9. Click OK pn the pop-up window.

9. Close the EXCEL application, without saving it again, (LIMS will not upload the file if it is in use). Click DON'T SAVE in the pop-up window.

Uploading Data to LIMS

1. Launch MegaUploadaTron (MUT, Applications Folder: IODP) if it is not already running.

2. Check to see if the AVS file(s) are present on the screen. If not, select the proper Upload Directory in the MUT application under File.

3. Click on the directory of choice (e.g., C:/gantry/IN) and check the MUT dialog window. The files to be uploaded should be present in this window.

4. Select the files to be uploaded, or use the Select All checkbox in the lower left corner of MUT.

5. Click the Upload button to load the data into LIMS. Note: MUT will automatically search the .CSV data file and select the peak shear value.

6. Users may also check the Automatic Upload checkbox for future uploads without any user intervention required.

Retrieve Data from LIMS

1. Go to LIMS Reports at http://web.ship.iodp.tamu.edu/LORE/.

2. Under Select Report, choose Physical Properties > Shear Strength Automated Vane (AVS).

3. Under Select Sample Range, specify Expedition, Site, Hole, and Section data to retrieve.

4. Click View data or Download data file to view data on screen or download a CSV file.

LIMS Component Table

ANALYSIS	TABLE	NAME (expanded report)	NAME (standard report)	ABOUT TEXT
AVS	SAMPLE	Exp	Exp	Exp: expedition number
AVS	SAMPLE	Site	Site	Site: site number
AVS	SAMPLE	Hole	Hole	Hole: hole number
AVS	SAMPLE	Core	Core	Core: core number
AVS	SAMPLE	Type	Type	Type: type indicates the coring tool used to recover the core (typical types are F, H, R, X).
AVS	SAMPLE	Sect	Sect	Sect: section number
AVS	SAMPLE	A/W	A/W	A/W: archive (A) or working (W) section half.
AVS	SAMPLE	text_id	Text ID	Text_ID: automatically generated database identifier for a sample, also carried on the printed labels. This identifier is guaranteed to be unique across all samples.
AVS	SAMPLE	sample_number	N/A	Sample Number: automatically generated database identifier for a sample. This is the primary key of the SAMPLE table.
AVS	SAMPLE	label_id	N/A	Label identifier: automatically generated, human readable name for a sample that is printed on labels. This name is not guaranteed unique across all samples.
AVS	SAMPLE	sample_name	N/A	Sample name: short name that may be specified for a sample. You can use an advanced filter to narrow your search by this parameter.
AVS	SAMPLE	x_sample_state	N/A	Sample state: Single-character identifier always set to "W" for samples; standards can vary.
AVS	SAMPLE	x_project	N/A	Project: similar in scope to the expedition number, the difference being that the project is the current cruise, whereas expedition could refer to material/results obtained on previous cruises
AVS	SAMPLE	x_capt_loc	N/A	Captured location: "captured location," this field is usually null and is unnecessary because any sample captured on the JR has a sample_number ending in 1, and GCR ending in 2
AVS	SAMPLE	location	N/A	Location: location that sample was taken; this field is usually null and is unnecessary because any sample captured on the JR has a sample_number ending in 1, and GCR ending in 2
AVS	SAMPLE	x_sampling_tool	N/A	Sampling tool: sampling tool used to take the sample (e.g., syringe, spatula)
AVS	SAMPLE	changed_by	N/A	Changed by: username of account used to make a change to a sample record
AVS	SAMPLE	changed_on	N/A	Changed on: date/time stamp for change made to a sample record
AVS	SAMPLE	sample_type	N/A	Sample type: type of sample from a predefined list (e.g., HOLE, CORE, LIQ)
AVS	SAMPLE	x_offset	N/A	Offset (m): top offset of sample from top of parent sample, expressed in meters.
AVS	SAMPLE	x_offset_cm	N/A	Offset (cm): top offset of sample from top of parent sample, expressed in centimeters. This is a calculated field (offset, converted to cm)
AVS	SAMPLE	x_bottom_offset_cm	N/A	Bottom offset (cm): bottom offset of sample from top of parent sample, expressed in centimeters. This is a calculated field (offset + length, converted to cm)
AVS	SAMPLE	x_diameter	N/A	Diameter (cm): diameter of sample, usually applied only to CORE, SECT, SHLF, and WRND samples; however this field is null on both Exp. 390 and 393, so it is no longer populated by Sample Master
AVS	SAMPLE	x_idmp
AVS	SAMPLE	x_orig_len	N/A	Original length (m): field for the original length of a sample; not always (or reliably) populated
AVS	SAMPLE	x_length	N/A	Length (m): field for the length of a sample [as entered upon creation]
AVS	SAMPLE	x_length_cm	N/A	Length (cm): field for the length of a sample. This is a calculated field (length, converted to cm).
AVS	SAMPLE	status	N/A	Status: single-character code for the current status of a sample (e.g., active, canceled)
AVS	SAMPLE	old_status	N/A	Old status: single-character code for the previous status of a sample; used by the LIME program to restore a canceled sample
AVS	SAMPLE	original_sample	N/A	Original sample: field tying a sample below the CORE level to its parent HOLE sample
AVS	SAMPLE	parent_sample	N/A	Parent sample: the sample from which this sample was taken (e.g., for PWDR samples, this might be a SHLF or possibly another PWDR)
AVS	SAMPLE	standard	N/A	Standard: T/F field to differentiate between samples (standard=F) and QAQC standards (standard=T)
AVS	SAMPLE	login_by	N/A	Login by: username of account used to create the sample (can be the LIMS itself [e.g., SHLFs created when a SECT is created])
AVS	SAMPLE	login_date	N/A	Login date: creation date of the sample
AVS	SAMPLE	legacy		Legacy flag: T/F indicator for when a sample is from a previous expedition and is locked/uneditable on this expedition
AVS	TEST	test changed_on		TEST changed on: date/time stamp for a change to a test record.
AVS	TEST	test date_started
AVS	TEST	test group_name
AVS	TEST	test status
AVS	TEST	test old_status
AVS	TEST	test test_number
AVS	TEST	test date_received		TEST date received: date/time stamp for the creation of the test record.
AVS	TEST	test instrument		TEST instrument [instrument group]: field that describes the instrument group (most often this applies to loggers with multiple sensors); often obscure (e.g., user_input)
AVS	TEST	test analysis		TEST analysis: analysis code associated with this test (foreign key to the ANALYSIS table)
AVS	TEST	test x_project		TEST project: similar in scope to the expedition number, the difference being that the project is the current cruise, whereas expedition could refer to material/results obtained on previous cruises
AVS	CALCULATED	test version
AVS	CALCULATED	test order_number
AVS	RESULT	test replicate_test
AVS	RESULT	test replicate_count
AVS	RESULT	test sample_number		TEST sample number: the sample_number of the sample to which this test record is attached; a foreign key to the SAMPLE table
AVS	RESULT	Depth CSF-A (m)	Depth CSF-A (m)	Depth CSF-A (m): position of observation expressed relative to the top of the hole.
AVS	RESULT	Depth CSF-B (m)	Depth CSF-B (m)	Depth [other] (m): position of observation expressed relative to the top of the hole. The location is presented in a scale selected by the science party or the report user.
AVS	RESULT	giesa_raw_asman_id link		RESULT instrument: name of the instrument used
AVS	RESULT	giesa_raw_filename		RESULT needle name: serial number of the needle used (H#### for half-space; V#### for full-space)
AVS	RESULT	max_torque_angle (deg)		RESULT number of solutions: number of independent valid solutions the SAM method found; the higher this number, the better (and <100 should be carefully checked)
AVS	RESULT	offset (cm)	Offset (cm)	RESULT offset (cm): position of the measurement relative to the top of a sample (generally a section)
AVS	RESULT	penetration_direction		RESULT spreadsheet uploader ASMAN_ID: serial number of the ASMAN link for the spreadsheet uploader file
AVS	RESULT	rotation_rate (deg/sec)		RESULT spreadsheet uploader filename: file name of the spreadsheet uploader file
AVS	RESULT	shear_strength (kN/mÂ²)		RESULT start time (s): the starting time of the experiment in seconds from initialization
AVS	RESULT	vane		RESULT average thermal conductivity (W/(m*K), SAM): mean result of successive thermal conductivity observations using the SAM method
AVS	SAMPLE	sample description	Sample comments	SAMPLE comment: contents of the SAMPLE.description field, usually shown on reports as "Sample comments"
AVS	TEST	test test_comment	Test comments	TEST comment: contents of the TEST.comment field, usually shown on reports as "Test comments"
AVS	RESULT	result comments	Result comments	RESULT comment: contents of a result parameter with name = "comment," usually shown on reports as "Result comments"

Credits

This document originated from Word document AVS_QSG_372.docx (see Archived Versions below for a file copy) written by T. Cobb (2017-12-18). Credits for subsequent changes to this document are given in the page history.

All improvements to the Quick Start Guides and User Guides are a communal effort, with honorable mention to the group of LOs, ALOs, and technicians who have helped.

Archived Versions

AVS Quick Start Guide - 27Sept2022
AVS Quick Start Guide 2020 (*.pdf)
AVS_QSG_372.docx: Written by T. Cobb (2017-12-18)

Laboratory Manuals, Guides, and Resources

Automated Vane Shear (AVS) Quick Start Guide

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