Appendix D Geotechnical report App · MCU18/0013

NOTES RELATING TO THIS REPORT

 

 

 

 

 

INTRODUCTION

These notes are provided by Soil Surveys Engineering
Pty Limited (the Company) to complement the
geotechnical report in regard to classification methods
and field procedures. Not all notes are necessarily
relevant to all reports.

The ground is a product of continuing natural and
man-made processes and therefore exhibits a variety
of characteristics and properties which vary from place
to place and can change with time. Geotechnical
engineering involves gathering and assimilating limited
facts about these characteristics and properties in
order to understand or predict the behaviour of the
ground on a particular site under certain conditions.
This report may contain such facts obtained by
excavation, probing, sampling, testing or
If so, they are directly

inspection,
other means of investigation.
relevant only to the ground at the place where and at
the time when the investigation was carried out.
DESCRIPTION AND CLASSIFICATION METHODS
Soils - The methods of description and classification of
soils and rocks used in this report are based on
Australian Standard 14726-1993 (Geotechnical Site
Investigations), where appropriate.
descriptions cover the following properties - soil or tock
type, colour, structure, strength or density, and
inclusions. Identification and classification of soil and
rock involves judgement and the Company infers
to the extent that is common in current

In general,

accuracy only
geotechnical practice.

Soil types are described according to the dominant
particle size and behaviour as set out in AS
1726-1993.

Cohesive soils are classified on the basis of strength
(consistency) either by use of hand penetrometer,
vane, laboratory testing oF engineering
The strength terms are defined in

shear
examination.
AS1726-1993 Table A4.

Non-cohesive soils are classified on the basis of
relative density usually based on insitu testing or
engineering examination (see AS1726-1993 Table A5).
Rocks - Rock types are classified by their geological
names (AS1726-1993 Table A6), together with

Table 1 Estimated strength descriptions given to rock

based on engineering examination

  

 

 

 

 

 

 

Extremely Weak <1.0
Very Weak 1.0-5.0
Weak 5.0-25
Medium Strong 25 - 50
Strong 50 - 100
Very Strong 100 - 250
Extremely Strong > 250

 

 

 

 

 

Ref ISRM "Suggested Methods for the Quantitative
Description of Discontinuities in Rock Masses"

descriptive terms regarding weathering (AS1726-1993
Table AQ), strength (refer Table 1

below), defects (AS1 726-1993 Table A10), etc. Where
strength testing (ie Point Loads) is carried out,
AS1726-1993 Table A8 is used. Where relevant,
further information regarding rock classification is
attached.

SAMPLING

Sampling is carried out during drilling or from other

 

excavations to allow engineering examination (and
laboratory testing where required) of the soil or rock.

Disturbed samples taken during drilling provide
information on plasticity, grain size, colour, moisture
content, minor constituents and, depending upon

sample disturbance, (information on strength and
structure).
Undisturbed samples are taken by pushing a thin

walled sample tube, usually 50mm diameter (U50), into
the soil and withdrawing it with a sample of the soil
contained in a relatively undisturbed state. Such
samples yield information on structure and strength,
and are necessary for laboratory determination of
shear strength, volume change potential and
compressibility. Undisturbed sampling is generally
effective only in cohesive soils.

Details of the type and method of sampling used are

given on the attached logs.

 

 

 

NOTEREP.SAM

SO

SOIL SURVEYS ENGINEERING