GEOTECHNICAL CAPABILITIES

 

Geotechnical Services

Our knowledge of the soils and geology in Southern Inland NSW are second to none.

Based on this we are able to provide scientifically sound geotechnical data and interpretation to qualified engineers to design, analyse and test their foundation systems.

Our laboratory is NATA accredited and qualified staff are Certified Professional Soil Scientists (CPSS) meaning we have a high-level professional competence in soil science and management, derived from a broad soil science knowledge base.

 
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Our laboratory is NATA accredited with a quality system that complies with the requirements of ISO/IEC 17025

 

GEOTECHNICAL INVESTIGATION

Geotechnical investigations are our specialty and we pride ourselves on delivering practical and cost-effective solutions for our clients. Our expert knowledge of soil and geology in Southern Inland NSW is the hallmark of our work. Our reports follow the two formats prescribed in the Australian Standard ‘AS 1726 - Geotechnical Site Investigations’, namely:

  1. Geotechnical Data Report (GDR) - This report is an important first step and documents the procedures used and the data collected. It includes:

    • The objectives and agreed scope.

    • The location and description of the project site and its history.

    • Plan showing investigation locations.

    • Description of the regional and local geology.

    • Records of fieldwork, including methods and results.

    • Laboratory testing and summary of results.

  2. Geotechnical Interpretative Report (GIR) - This report is formulated as second step as more design information about the project becomes available. It includes:

    • Reference to the data upon which the interpretation has been made.

    • An interpretation of the site geology and the development of the geotechnical model.

    • A summary of the geotechnical properties of the ground applicable to the project.

    • An interpretation of the implications of the ground conditions for the project.

    • An assessment of potential geotechnical risks to the project.

    • Recommendations for further work, if relevant.

 

Field and Laboratory Testing

McMahon has the capability for high quality field and laboratory testing and our construction material testing facility is NATA accredited which assures quality of results. We cover a wide range of tests for material suitability in our NATA facility.

SOILS

  • Sampling from earthworks, stockpile, windrow and pavement

  • Compressive strength

  • Density (compaction control)

  • Level 1 and 2 earthworks supervision

  • Relative compaction

  • Bearing ratio (CBR)

  • Permeability

  • Dry density/moisture

  • Linear shrinkage

  • Plasticity

  • Sieve analysis (particle size distribution)

  • Earth resistivity measurement

AGGREGATE

  • Sampling from stockpile, windrow, truck and pavement

  • Wet/dry strength

  • Aggregate crushing value

  • Particle shape

  • Average least dimension

  • Crushed faces

  • Flakiness

  • Proportional calliper

  • Particle density of coarse and fine aggregate

  • Water absorption of coarse and fine aggregate

  • Bulk density – compacted and uncompacted

  • Particle size distribution

  • Foreign materials

  • Organic impurities

  • Clay and fine silt

CONCRETE

  • Sampling from a mixer, deposited concrete and coring

  • Slump flow

  • Wet sieving analysis

  • Mass per unit volume

  • Compressive strength

  • Air content of freshly mixed concrete

  • Specimen condition

  • Specimen curing

 

RESEARCH AND DEVELOPMENT

We are always working on research and development to improve what we do:

  • Can the shrink-swell index be predicted in the Wagga Wagga region based on Atterberg limits? Australian Geomechanics | Vol 59 No 1 [March 2024] · Mar 1, 2024.

  • Relationship between soil strength and soil moisture of soils within the Wagga Wagga area. Ready for publication sometime in 2024.

  • We are working with UNSW on a long term project for soft soil (silt) engineering in Wagga Wagga.