Compiled Reference Documents - MCU25/0091 (As Published)

                                                METHOD OF SOIL DESCRIPTION USED ON BOREHOLE AND TEST PIT
                                                REPORTS
                               FILL                                                          CLAY (CL,CI, or CH)

                               GRAVEL (GP or SW)                                             ORGANIC SOILS (OL or OH or Pt)


                               SAND (SP or SW)                                               COBBLES or BOULDERS

                               SILT (ML or MH)

    Combinations of these basic symbols may be used to indicate mixed materials such as sandy clay.

    CLASSIFICATION AND INFERRED STRATIGRAPHY
    Soil and Rock is classified and described in Reports of Boreholes and Test Pits using the preferred method given in AS 1726 - 2017. The material proper-
    ties are assessed in the field by visual/tactile methods.

                             PARTICLE SIZE                                                                  PLASTIC PROPERTIES

          Major
                        Sub Division               Particle Size
         Division

                   Boulders                          >200 mm

                   Cobbles                         63 - 200 mm

          Gravel              Coarse               20 - 63 mm

          Gravel             Medium                6.7 - 20 mm

          Gravel               Fine               2.36 - 6.7 mm

          Sand                Coarse              0.6 - 2.36 mm

          Sand               Medium               0.21 - 0.6 mm

          Sand                 Fine             0.075 - 0.21 mm


                     Silt                    0.002 - 0.075 mm

                    Clay                           <0.002 mm

    MOISTURE CONDITION FOR COARSE GRAINED SOIL                        AS 1726 - 2017

    Symbol             Term                                           Description

    D                  Dry                                            Non-cohesive and free running

    M                  Moist                                          Soil feels cool, darkened in colour, tends to stick together

    W                  Wet                                            Soil feels cool, darkened in colour, soil sticks together, free water forms when handling

    MOISTURE CONDITION FOR FINE GRAINED SOIL                          AS1726 - 2017


    Symbol             Term                                           Description
    W<PL               Moist dry of liquid limit                      Hard and friable or powdery
    W = PL             Moist near plastic limit                       Soils can be molded at a moisture condition approximately equal to the plastic limit
    W >PL              Moist, wet of plastic limit                    Soils usually weakened and free water forms on hands when handling
    W = LL             Wet near plastic limit
    W > LL             Wet, wet of liquid limit
    CONSISTENCY TERMS FOR                           AS1726—2017           RELATIVE DENSITY OF COARSE GRAINED SOILS                                   AS1726—2017
    COHESIVE SOILS
                                                                          Symbol                 Term                      Density Index %           SPT ‘N’ #
    Symbol           Term                           Undrained Shear
                                                                          VL                     Very Loose                Less than 15              0 to 4
                                                    Strength
                                                                          L                      Loose                     15 to 35                  4 to 10
    VS               Very Soft                      0 to 12 kPa

    S                Soft                           12 to 25 kPa          MD                     Medium Dense              35 to 65                  10 to 30

    F                Firm                           25 to 50 kPa          D                      Dense                     65 to 85                  30 to 50

    St               Stiff                          50 to 100 kPa         VD                     Very Dense                Above 85                  Above 50

    VSt              Very Stiff                     100 to 200 kPa        In the absence of test results, consistency and density may be assessed from correlations with
                                                                          the observed behaviour of the material.
    H                Hard                           Above 200 kPa
Document Set ID: 24031832
Version: 1, Version Date: 14/08/2025