2016-03-01 Planning & Organisation Committee Agenda

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Soil Descriptions                                                                                  i ID

 Description and Classification Methods                    -
 The methods of description and classification of     Definitions of grading terms used are:
 soils and rocks used in this report are based on     e   Well graded - a good representation of all
Australian Standard AS 1726, Geotechnical Site            particle sizes
 Investigations Code. In general, the descriptions    *   Poorly graded - an excess or deficiency of
 include strength or density, colour, structure, soil     particular sizes within the specified range
 or rock type and inclusions.                                .                                   .
                                                      e   Uniformly graded - an excess of a particular
 Soil Types                                               particle size
 Soil  types  are  described   according  to  the     *   Gap graded - a deficiency of a particular
 predominant particle size, qualified by the grading      particle size with the range
 of other particles present:
                                                      Cohesive Soils
                           Particle size (mm)         Cohesive soils, such as clays, are classified on the
                                                      basis of undrained shear strength. The strength
  Cobble                       63 - 200               may   be  measured    by  laboratory testing, oF
                                                      estimated   by   field  tests   or   engineering
                               2.36 - 63              examination.  The strength terms are defined as
                             0.075 - 2.36             follows:
                             0.002 -0.075
                                <0.002                 Description      Abbreviation      Undrained
                                                                                        shear strength
 Th       d    id       1  si         be   furth                                            _
    hdividedasfollows SS StStSS:tCt«<‘<‘~i               rvs, =       Tvs Tt
 subdivided as follows:                                Very soft             vs              <12
                                                     [sot             |     ts | 12-25
                           Particle size (mm)                                              25 - 50
                                20-63                                                     50 - 100
  Medium gravel                                        Very stiff                         100 - 200
                               236-6               Fr
                              0.6 -2.36
                               02-06                  Cohesionless Soils
                              0075-02                 Cohesionless soils, such as clean sands, are
    mESSen                     ;      a               classified on the basis of relative density, generally
            ;                      .           .      from the results of standard penetration tests
 The proportions of secondary constituents of soils   (SPT), cone penetration tests (CPT) or dynamic
 are described as:                                    penetrometers (PSP).   The relative density terms
                                                      are given below:
  And                Specify     Clay (60%) and        Relative    Abbreviation     SPT N     CPT qc
                                   Sand (40%)         Density                       value      value
  ens _| eons |                    sso
  Slightly          12-20% |      Slightly Sandy         =               :
                                     Clay            [loose      |      |       | 4-10 | 2-5 |
  With some          5-12%       Clay with some        Medium                       10 - 30    5-15
                                      sand             dense
  With atraceof | 0-5% | Clay witha trace             [Dense | =d_             | 30-50 | 15-25
                                     of sand          Very               vd          >50        >25
                                                       dense

                                                                                              July 2010

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