Compiled Reference Documents - OPW25/0053 (As Published)

                                                                                               Terminology
Soil Descriptions                                                                                 Symbols
                                                                                              Abbreviations


Compaction (anthropogenically modified soil)          Cementation (natural and anthropogenic)
   Compaction Term       Abbreviation Code              Cementation Term         Abbreviation Code
 Well compacted         `WC`                           Moderately cemented      `MOD`
 Poorly compacted       `PC`                           Weakly cemented          `WEK`
 Moderately compacted `MC`
 Variably compacted     `VC`

Extremely Weathered Material
AS1726-2017 considers weathered material to be soil if the unconfined compressive strength is less than
0.6 MPa (i.e. less than very low strength rock). These materials may be identified as “extremely weathered
material” in reports and by the abbreviation code `XWM` on log sheets. This identification is not correlated
to any specific qualitative or quantitative behaviour, and the engineering properties of this material must
therefore be assessed according to engineering principles with reference to any relic rock structure, fabric,
or texture described in the description.

Soil Origin
            Term                                   Description                                Abbreviation
                                                                                                  Code
 Residual                Derived from in-situ weathering of the underlying rock               `RS`
 Extremely               Formed from in-situ weathering of geological formations. Has         `XWM`
 weathered material      strength of less than ‘very low’ as per as1726 but retains the
                         structure or fabric of the parent rock.
 Alluvial                Deposited by streams and rivers                                      `ALV`
 Fluvial                 Deposited by channel fill and overbank (natural levee, crevasse      `FLV`
                         splay or flood basin)
 Estuarine               Deposited in coastal estuaries                                       `EST`
 Marine                  Deposited in a marine environment                                    `MAR`
 Lacustrine              Deposited in freshwater lakes                                        `LAC`
 Aeolian                 Carried and deposited by wind                                        `AEO`
 Colluvial               Soil and rock debris transported down slopes by gravity              `COL`
 Slopewash               Thin layers of soil and rock debris gradually and slowly             `SW`
                         deposited by gravity and possibly water
 Topsoil                 Mantle of surface soil, often with high levels of organic material   `TOP`
 Fill                    Any material which has been moved by man                             `FILL`
 Littoral                Deposited on the lake or seashore                                    `LIT`
 Unidentifiable          Not able to be identified                                            `UID`

Cobbles and Boulders
The presence of particles considered to be “oversize” may be described using one of the following
strategies:
•    Oversize encountered in a minor proportion (when considered relative to the wider area) are noted in
     the soil description; or
•    Where a significant proportion of oversize is encountered, the cobbles/boulders are described
     independent of the soil description, in a similar manner to composite soils (described above) but
     qualified with “MIXTURE OF”.




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