14169-001-Rev0 17 Webb Rd -Revised Draft · 132002.220527.1

                                                                         METHOD OF SOIL DESCRIPTION
                                                                                      USED ON LOGS
CLASSIFICATION AND INFERRED STRATIGRAPHY
Soil and rock is classified and described in borehole and test pit logs using the preferred method given in AS1726 – 1993,
(Amdt1 – 1994 and Amdt2 – 1994), Appendix A.The material properties are assessed in the field by visual/tactile methods.
Particle Size                                                                      Plasticity Properties

Major Division Sub Division            Particle Size40
          BOULDERS                     > 200 mm
          COBBLES                     63 to 200 mm
                   Coarse              20 to 63 mm
 GRAVEL           Medium               6.0 to 20 mm
                       Fine           2.0 to 6.0 mm
                   Coarse             0.6 to 2.0 mm
                                                         C
  SAND            Medium              0.2 to 0.6 mm
                   Fine               0.075 to 0.2 mm
                SILT                   0.002 to 0.075
             CLAY                      < 0.002 mm mm



MOISTURE CONDITION                                                AS1726 - 1993
Symbol     Term    Description
   D
   M
                  Dry
                 Moist
                                                 T
                              Sands and gravels are free flowing. Clays & Silts may be brittle or friable and powdery.
                              Soils are darker than in the dry condition & may feel cool. Sands and gravels tend to cohere.
                                              AF
   W              Wet         Soils exude free water. Sands and gravels tend to cohere.

CONSISTENCY AND DENSITY                                          AS1726 - 1993
 Symbol     Term        Undrained Shear                        Symbol        Term             Density Index %        SPT “N” #
                           Strength
    VS           Very Soft             0 to 12 kPa               VL         Very Loose          Less than 15              0 to 4
                                   R

    S              Soft               12 to 25 kPa                L            Loose               15 to 35              4 to 10
    F              Firm               25 to 50 kPa               MD       Medium Dense             35 to 65          10 to 30
    St             Stiff              50 to 100 kPa               D            Dense               65 to 85          30 to 50
                           D


    VSt          Very Stiff          100 to 200 kPa              VD         Very Dense            Above 85           Above 50
     H            Hard             Above 200 kPa
In the absence of test results, consistency and density may be assessed from correlations with the observed behaviour of
the material.
# SPT correlations are not stated in AS1726 – 1993, and may be subject to corrections for overburden pressure and
equipment type.




                                                                                                                                           Rev0
                                                                                                                                   October 2013