MSL974028
Classify soils


Application

This unit of competency describes the skills and knowledge to classify soils for geotechnical and civil construction purposes using the symbols and descriptors specified in the Australian Standard for Geotechnical Site Investigations (AS 1726-2017 Geotechnical site investigations, or its replacement). The unit involves confirming the client’s requirements, physical examination of site samples, interpreting field observations and test results and assignment of an appropriate soil classification. Personnel are expected to recognise and rectify obvious errors or unexpected results, perform confirmatory tests if required and seek advice to deal with situations beyond their own technical competence.

This unit applies to laboratory technicians working in the construction, mining and drilling industry sectors under the guidance of a geotechnical paraprofessional or engineer.

No licensing or certification requirements exist at the time of publication. However, regulations and/or external accreditation requirements for laboratory operations exist, so local requirements should be checked. Relevant legislation, industry standards and codes of practice within Australia must also be applied.


Elements and Performance Criteria

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1

Prepare to classify soil samples

1.1

Review job request and any accompanying documentation to identify purpose of soil classification and client’s information needs

1.2

Identify any hazards and relevant safe work procedures associated with the types of site samples

1.3

Inspect supplied samples and test data, compare with specifications and record and report any discrepancies

1.4

Liaise with client when supplied samples, test data and/or job request forms do not comply with workplace procedures and resolve any problems

1.5

Assemble required equipment/materials and check that they are fit for purpose

2

Examine properties of soil samples

2.1

Assess appearance and feel of soil to determine moisture condition

2.2

Use moulding/indentation tests, penetrometer and/or density index data to determine soil consistency

2.3

Identify the soil’s major, secondary and minor components and the proportion of each

2.4

Assign a soil colour based on own observations and review of field log sheets

2.5

Determine soil structure based on own observations and review of available zoning, defect and cementing data recorded for undisturbed field samples

2.6

Review any additional observations and test data that may identify soil origin

3

Analyse available test results

3.1

Compare supplied mechanical test data with standard classification values for different soil types

3.2

Compare particle size and percentage composition data with standard classification values for different soil types

3.3

Compare other laboratory test results with own observations to confirm assignment of plasticity, grading and strength of soil samples

3.4

Recognise anomalies or unexpected results and, if necessary, recheck specimens and test results and conduct repeat tests to ensure reliable results

4

Record soil classification

4.1

Use standard symbols and descriptors to assign a valid soil classification

4.2

Record and store client’s soil classification, samples and test data in accordance with workplace procedures

4.3

Maintain confidentiality of client information in accordance with workplace procedures

5

Maintain a safe work environment

5.1

Use safe work procedures and personal protective equipment (PPE) to ensure personal safety and that of other personnel

5.2

Clean work area and collect, recycle or dispose of all waste in accordance with workplace procedures

5.3

Clean and check serviceability of test equipment before storage

Foundation Skills

This section describes those language, literacy, numeracy and employment skills that are essential to performance.

Numeracy skills to:

read graphs and tables to extract classification data, such as D10, D30 and D60 points

perform accurate calculations, such as coefficients of curvature and uniformity for gravels and sands.

Other foundation skills essential to performance are explicit in the performance criteria of this unit.


Competency Field

Testing