1 - GEOTECHNICAL INVESTIGATION REPORT - 150320 LAR Road Investigation Ridgewood Geotech 23042015_Rev1-Combined

                                               GEOTECHNICAL TERMS AND SYMBOLS
Introduction
This document is intended to provide assistance in the interpretation of the terms and symbols used
on the geological logs report sheets for non-cored and cored drill holes and excavations. Soil and
rock are described and classified using the preferred methods presented in Appendix A of AS 1726 -
1993 “Geotechnical site investigations”.

Soil Description
Soil properties are described in the field using visual and tactile methods. The following provides
further details of the descriptions shown on the geological logs.
CLASSIFICATION TERMS
Particle Size                                              Plasticity Properties
   Major
               Sub Division           Particle Size
  Division
         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
   SAND          Medium               0.2 to 0.6 mm
                   Fine             0.075 to 0.2 mm
            SILT                   0.002 to 0.075 mm
           CLAY                        < 0.002 mm


CONSISTENCY TERMS – Cohesive Soils
                 Undrained Shear                                              Field Guide
    Term
                     Strength
  Very Soft         0 to 12 kPa          A thumb can be pushed well into the soil with little effort.
    Soft           12 to 25 kPa         Readily remoulded with finger pressure.
    Firm           25 to 50 kPa         Can be remoulded with significant finger pressure.
                                        Cannot be remoulded by finger pressure but thumb can cause an indent in the soil
     Stiff         50 to 100 kPa
                                         surface.
  Very Stiff      100 to 200 kPa         Cannot be remoulded by finger pressure but thumb can mark the surface.
    Hard          Above 200 kPa          The surface of the soil can only be indented by the thumb nail.

RELATIVE DENSITY TERMS - Non-cohesive Soils
                     Density Index        SPT "N"                                      Field Guide
       Term
                            %              Value
  Very Loose          Less than 15          0 to 4      Foot pressure leaves an indent in the soil surface.
    Loose               15 to 35           4 to 10      Shovels easily.
 Medium Dense           35 to 65          10 to 30      Shovelling difficult.
    Dense               65 to 85          30 to 50      Pick required.
  Very Dense           Above 85           Above 50      Picking difficult.
Notes:
1. In the absence of test result, consistency and density are assessed based on the field guide.
2 SPT correlations are approximate only and should take into consideration the overburden pressure at the test depth and equipment
   type.




                                                                                                                 Rev0, 20/09/2013