RFI 10.03.2020 - Appendix C - Memorandum cooroibah waterway crossing · MCU16/0099.01

1.       Explanatory notes and abbreviations
The following information provides the terms and abbreviations used in Aurecon geotechnical
borelogs and reports. Description of soil and rock are generally in accordance with the Unified Soil
Classification System and Australian Standard AS1726-2017, Geotechnical Site Investigations. Soil
and rock descriptions using established field techniques have been recorded independent of any
laboratory test results. As far as is practicable the data contained on the log sheets is factual. Some
interpretation is inevitable in the assessment of conditions between samples and of the origin of the
materials.
Assessment of potential site contamination does not form part of this geotechnical report. Any
reference to potential contaminants is for information only, and does not necessarily indicate the
presence or absence of soil or groundwater contamination.


1.1 Soil Description
Soils are generally described in the borehole log using the following sequence of terms:
[Drilling Information]; [USC Symbol]; [Soil Type, Colour, Plasticity/Particle Description, Structure];
[Moisture Condition]; [Consistency]

Unified Soil Classification Group Symbols
Typical Names                                  USC Symbol        Typical Names                                 USC
                                                                                                               Symbol
Well graded gravels                            GW                Well graded sands                             SW
Poorly graded gravels                          GP                Poorly graded sands                           SP
Silty gravels                                  GM                Silty sands                                   SM
Clayey gravels                                 GC                Clayey sands                                  SC
Inorganic silts of low plasticity.             ML                Inorganic clay of low plasticity              CL
Inorganic silts of high plasticity             MH                Inorganic clay of medium plasticity           CI
Organic silts of low plasticity                OL                Inorganic clays of high plasticity            CH
Organic clays of high plasticity               OH                Peat and other highly organic soils           Pt


Soil Type and Particle Size
Major Divisions                                                  Symbols        Subdivision         Particle Size
Coarse Grained Soils                 Boulders                                                       > 200 mm
(more than 65% of                    Cobbles                                                        63 mm – 200 mm
material                             Gravels                     G              Coarse              19 mm – 63 mm
is larger than 0.075mm)              (more than half of coarse                  Medium              6.7 mm – 19 mm
                                     fraction is larger than
                                                                                Fine                2.36 mm – 6.7 mm
                                     2.36mm)
                                     Sands                       S              Coarse              0.6 mm – 2.36 mm
                                     (more than half of coarse                  Medium              0.21 mm – 0.6 mm
                                     fraction is smaller than
                                                                                Fine                75 µm – 0.21 mm
                                     2.36mm)
Fine Grained Soils                   Silts                       M                                  < 75 µm
(more than 35% of                    Clays                       C
material is smaller than             Organic                     O
0.075mm)




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NOTES\EXPLANATORY NOTES AURECON 2018 V2 (002).DOC  26 February 2018  PAGE 1