Soil Report - S

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INTRODUCTION
Unearthed Geotechnical P/L was commissioned to undertake a Site Investigation in
the Noosa Council at

Lot 4 on RP905954 (26) Little Springs Lane, Lake Macdonald.
(GPS coordinates 26°21°54"s, 152°55’58"e),

for the proposed house and shed on this vacant 7132 square-metre allotment.

Our site investigation fieldwork was performed on 2/09/2020 after generally fine
weather in the course of the preceding weeks.

This report does not include an assessment of slope stability or landslide risk.

The standards and references used in compiling or referred to in this report are,
The Queensland Building & Construction Commission,

AS 1289-2014 Methods of testing soils for engineering purposes,

AS 2870-2011 Residential Slabs and Footings,

AS 3798-2007 Guidelines earthworks commercial & residential developments,
AS 1726-2017 Geotechnical Site Investigations.

 

COPYRIGHT ™:

Copyright in the whole and every part of the drawings, specifications and other
documents provided by Unearthed Geotechnical P/L remain the property of the
Unearthed Geotechnical P/L. Upon receipt of full payment for our service the client
is licensed to use the drawings, specifications and other documents for the work/s for
which they were commissioned. They shall not be used for any other work except by
agreement with Unearthed Geotechnical P/L.

 

Unearthed Geotechnical P/L. 4 Site Investigation Report 020-212

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SITE INVESTIGATION

As with all site investigations we assume that the fundamental principles of good
construction will not be overlooked, and will be carried out with the consistent
application of ‘best practice’ techniques across the site and at each stage as these
factors are of great consequence.

The fieldwork undertaken for our site investigation included the following;

detailed subsoil investigation recording characteristics and limitations,

a comprehensive site assessment to record topography, geography and geology,
soil observation boreholes (75-100 mm dia. Jarret style hand augers),
penetrometer testing with 9kg Dynamic Cone Penetrometer (DCP),
classification and testing of hand collected soil samples, and

the collation and evaluation of the results from the above studies.

Be Be Ge He Ge

(The test locations were not professionally surveyed and should be considered approximate)
(All fieldwork performed in accordance with the relevant Australian Standards and Codes)
(All boreholes backfilled in accordance with Occupational Health and Safety regulations)

FIELD TEST LIMITATIONS

The soil profiles reported should generally be representative of the soil conditions across this
site. In some cases soil conditions can change dramatically, and can change over short
distances. If site works reveal soil conditions that are different from those shown in the
attached data, the evaluator must be informed immediately as changes may be necessary.

CLIENT SUPPLIED INFORMATION

This site investigation and classification has been undertaken in accordance with AS
2870 ‘Residential Slabs and Footings’. The Queensland Building & Construction
Commission's (QBCC) ‘Rectification of Building Work Policy' has a requirement for
the following information to be supplied to us, and that we consider this information
in determining the site classification. This information includes, but is not limited to;
Property description and site address,

Evidence to ensure site is correct (e.g. Survey Plan, Registered Plan, etc),

Survey plan delineating contours, trees, existing developments, etc,

Land searches, including such information as flood lines, easements, covenants,
underground services and infrastructure, etc,

Any previous geotechnical work, e.g. original contour survey, and the limits of
prior subdivisional or developmental cutting and filling, service lines etc.

& The known extent of further developmental or construction earthworks

Be Se He He

9

In this instance and at the time of our commission, we have considered the
information supplied to us by the client. Should the client or his agent have omitted to
supply us with the QBCC required information or supplied us with incorrect
information our assessment may be irrelevant and/or inappropriate. However, should
this information become available we would be pleased to amend our report
accordingly, if, and as necessary. We do not take responsibility for the consequences
in such cases and may incur additional costs if as a result; more testing or re-writing
is necessary.

 

Unearthed Geotechnical P/L. 2 Site Investigation Report 020-212

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FINDINGS

All the field information and test results collected during our site investigation and
detailed in this report, including any site plans, log and data sheets together form the
basis of our recommendations.

The soil profile encountered during our investigations, and as reported, was
reasonably and acceptably consistent across the proposed development, and within
our expectations from regional experience and correlation with The Qld Dept of
Mines/Energy Geology Sheet 9445/1999 (Gympie), which describes the geology as
Late Triassic-Jurassic, Duckinwilla Group, Myrtle Creek Sandstone.

The proposed site is on a partially exposed 15-20% southeastern slope with
neighbouring vegetation consisting of grasses and trees. We recorded approximately
15 medium to large trees within, or adjacent to, the proposed site, that are likely to be
removed.

The landform was recorded as natural and partially disturbed.

Slope configuration across the proposed site is determined to be linear planar. Slope
stability problems were not evident during our investigations.

The susceptibility to flooding from groundwater is low and site drainage was recorded
as poor. No water table was encountered on the day of our site investigation.
However, during and for some time after periods of seasonal, heavy or extended
rainfall water seepage on the sand/clay interface may cause a loss of bearing capacity
at this level. Seepage may also cause collapse of excavations, which may increase
concrete volumes significantly above those normally anticipated.

Cobbles and/or boulders in soil profiles are sometimes common and unfortunately we
cannot predict their size or frequency. It has also been our experience that these
floaters can be extremely difficult to excavate with conventional equipment.
However, experience in this area has shown that beneath any floaters the soil grades
into stable weathered rock at relatively shallow depths.

The resistance of the soil encountered was tested with an approved 9kg Dynamic
Cone Penetrometer and the results recorded at the appropriate levels on the attached
log sections.

Existing Services.

We were not informed of any existing service line excavations and no existing service
line excavations were identified within or immediately adjacent to the proposed house
site.

 

Unearthed Geotechnical P/L. 3 Site Investigation Report 020-212

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The soil samples hand collected and classified from the proposed house site were
assessed as having low to negligible plasticity, therefore laboratory testing was
considered unnecessary.

The expected surface movement (Ys), due to seasonal moisture changes in the soil
encountered, is as follows

 

Ys Value = 0-20mm

 

 

 

 

Predicted Surface Movement Class

   

 

Ys=>20-—< 40mm M

 

 

 

 

Ys=>40-< 60 mm Hl
Ys=>60—-< 75 mm H2
Ys=>75 mm E
Problem sites P

 

 

 

 

Note: Our assessment does not consider the effect of the presence of trees within or
adjacent to the building site, nor the removal of trees prior to or after construction, nor
the growth of trees too close to the footings. The proximity of trees and their effect on
joundations should be considered when determining specific engineering assessments,
and for foundation/footing design. Appendix B of AS 2870-2011 indicates that to reduce,
but not eliminate, the possibility of damage to the footings, trees should be restricted to
the following distance from the building (where rows or groups of trees are present the
distance nominated below must be increased, and similarly the Ys Value listed above may
need to be increased) : 75% of the mature tree height, for class “M” sites, 100% of the
mature tree height, for class “H 1” sites, and 150% of the mature tree height, for
class “E” sites.

Note: This classification above has been derived from test work performed on the soil
profile encountered on the day of our fieldwork. Any further filling of the site or
excavation into the soil profile, may result in a different classification.

Temporary Excavations.

Where temporary excavations are performed for footing or services up to 600mm
deep, natural soils may have minor or no stability problems, however deeper
excavations have a possibility of collapse more readily and shoring of vertical
excavation may be required. Where an existing excavation has been filled with
uncontrolled fill, all locations above a line 30 degrees for sands and 45 degrees for
clays above the horizontal may be unstable and may not support any structure — see
attached critical depth line diagram.

 

Unearthed Geotechnical P/L. 4 Site Investigation Report 020-212

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LEGEND

   

 

       

Investigation Code
GP — Poorly graded gravels, little or no fines
GC — Clayey gravels

SP — Poorly graded sands, little or no fines
SC — Clayey sands

OL - Organic silts and organic silty clays
CI - Inorganic clays of medium plasticity
CH - Inorganic clays of high plasticity OH - Organic clays medium/high plasticity
Pt — Peat and other highly organic material Ls — Linear Shrinkage %

Note The stratifications identified on our log sheets are representative of the approximate boundary
between soil types and the transition may be gradual and vary over the site.

Soil descripti 1 the Geotechni
GW — Well graded gravels, little or no fines
GM - Silty gravels

SW — Well graded sands, little or no fines
SM - Silty sands

ML - Inorganic silts and very fine sands
CL ~ Inorganic clays of low plasticity

 

 

 

 

 

 

 

 

 

 

 

 

   

ion:
Dk - Dark, Lt— Light, Gy- Grey, Rd- Red, Br—Brown, Or-— Orange, Mott - Mottled.
LP, MP, HP - Low, Medium, High Plasticity. SW - Slightly Weathered Rock.
P (p) — blows/100 mm approved penetrometer DW - Distinctly Weathered Rock.
UTP — Unable to penetrate EW - Extremely Weathered Rock.

 

 

 

 

 

 

 

  
  

      

aring cap: Is
Soft (S) — 25 to 50 kPa
Very Stiff (VSt) — 200 to 400 kPa

 

 

Firm (F) — 50 to 100 kPa
Hard (H) — 400+ kPa

Very soft (Vs) —<25 kPa
Stiff (St)— 100 to 200 kPa

 

 

 

 

 

 

SPT “N” value Relative Density (%)

Density

Very Loose (VL)
Loose (L)
Medium Dense (MD)
Dense (D)

Very Dense (VD)

Boulder
Cobble

Gravel

Sand

Clay

Looks and feels dry, c!

Moist
Wet

soils are normally hard,
Feel cool, darkened in colour, no free water on hands when remoulding.
Soils are weak, free water can occur; granular soils bind together, clay softened.

<4

4-10
10 ~30
30-50
> 50

Coarse
Medium
Fine
Coarse
Medium
Fine

or friable.

<15
15-35
35-65
65-85
> 85

> 200
63 — 200
20 - 63

2-20
0.6 —2.0
0.2—0.6

0.075 — 0.2

0.002 — 0.075

< 0.002

 

 

Unearthed Geotechnical P/L.

5 Site Investigation Report 020-212

Page 7

 

   
 
 

   
   
 
 

Ground/pad level

This footing Is founded
above the critical depth

unstable line and is deemed to
be unstable.
+O
ey,
stable eu, Pliers must be excavated

to below the critical depth
line to provide stability to

“7
> these footings.

This footing is founded

below critical line and
Is stable

30 degrees oN,

(45 for clay) ~

 

Horizontal

Any proposed or existing excavation. The
builder must ensure all excavations are
discovered and the footing and slab Is
secured below the critical line accordingly.
This should Include a search of all council
& other records for as constructed plans to
establish excavation depths & widths.

“

 

 

Critical Depth line measured from deepest,
point of the excavation nearest the footing.

Critical Depth Line

 

 

~ In the case of a buried pipe the
invert level is usually above and
away from the nearest comer
of the excavation.

 

 

Unearthed Geotechnical P/L.

Site Investigation Report 020-212

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Lot 4 (#26) LITTLE SPRINGS LANE, LAKE MACDONALD.

020-212

 

 

 

 

 

 

EB

  

 

mely Weathered Rock Lenses) |__| 800

 

 

 

 

 

 

Silty Sand SP_ 1 [| 100 { 1
yBrown) _—«—s'‘|-« 3-:«[ 200 | 4 -
J _ Moist & Medium Dense___| _4 [300 | 5
_. Clayey Sand SC confer Sf 400 | 7 |
(Orange Brown Grey Mottled) 10 | 500 9
_... Moist & Dense | 12, | 600 | 11 |

 

 

 

 

 

Silty Sand SP
(Grey Brown) _

___Clayey Sand SC _

"(Orange Brown Grey Mottled)

 
 
 
  

 

900

UTP Hand Auger _ | Im

__ (Extremely Weathered Rock EW) {1100
1200

 

 

 

 

 

 

   

 

 

75-100 mm Jarret style Hand Auge

 
 

 

 

 

2/09/2020

 

 

   
   

 

 

 

100
200
300

 

 

 

 

400
500

 

 

 

600
700

 

 

800

 

“Moist & Friable_

 

900

 

 

_UTP Hand Auger

 
 

im
1100

 

 

 

 

1200

 

 

75-100 mm Jarret style Hand Augers.
Pp = blows/100mm - 9kg Dynamic Cone Penetrometer.

UTP = Unable to penetrate.

 

 

Note - All field information and test results collected during our site investigation and detailed in the
accompanying report, including any site plans, log and data sheets are only to be used for the purposes of this
report. No third party use of any part of this information is authorised without specific or written consent.

Page 9

 

 

 

BH2 BOREHOLE LOCATION AND NUMBER 20m
é LOCATION AND ASPECT OF PHOTO 1:1000(@a4) a

Owner/ClienvAgent - ANTHONY MCDONOUGH 0407 493 611

LOT 4 RP905954 (#26) LITTLE SPRINGS LANE, LAKE MACDONALD. Noosa Council. 020-212.
Do not scale. Site Drainage - Poor. Vegetation - Grasses & Trees. Slope - 15-20% Vertical:Horizontal

 

 

 

 

 

\.AJ TRELOAR (Copyright) Unearthed Geotechnical P/l.. PO Box 1204 Gympie 4570 [email protected] 0417 132 300 2i09/2020 _)

 

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