Transcript of Wyong Road Enviro Factors Appendix p
NB11462 Pacific Highway and Wyong Road intersection upgrade
Appendix P Review of Environmental Factors
Appendix P
MR335 Intersection and Approaches Upgrade
Geotechnical Investigations Report
Contents
1.3. Report structure 2
2. Project appreciation 3
3. Background review 5
3.3. Acid Sulfate Soil (ASS) assessment 7
3.4. Groundwater 8
3.6. Previous geotechnical investigations 9
3.6.1. RMS pavement investigation: 2523/01 9
3.6.2. RMS pavement investigation 2523/02 10
3.7. Site visit and inspection 11
4. Scope of geotechnical investigations 12
4.1. General 12
4.3. Borehole drilling 13
4.3.1. Monitoring wells 14
4.4. Cone Penetration Testing (CPTu) and Shear vane testing
(Su) 15
4.5. Test pits 16
4.6. Laboratory testing 17
5.1. Laboratory testing 19
6.2.1. (Unit 1) Fill 30
6.2.2. (Unit 2) Alluvial deposits 30
6.2.3. (Unit 3A) Residual soil 35
6.2.4. (Unit 4) Bedrock 37
6.3. Interpretation of CPTu Data 39
7. References 41
8. Limitations 43
Appendix A – Site investigation location plan and geotechnical
sections 45
Appendix B – Background information 46
Appendix C – Explanatory notes and engineering logs 52
Appendix D – Laboratory test certificates 59
Document history and status
Revision Date issued Reviewed by Approved by Date approved Revision
type
A 24 Sept 2012 S.Raynsford R.Casimir 24 Sept 2012 RMS
Review
B 28 Nov 2012 S.Raynsford R.Casimir 28 Nov 2012 Final
Distribution of copies
Printed: 27 November 2012
File name: NB11462-ESG-RP-0002_B_Geotechnical Investigations
Report.docx
Author: David Andrew
Name of organisation: Roads and Maritime Services (RMS)
Name of project: Pacific Highway & Wyong Road Intersection and
Approaches Upgrade
Name of document: Geotechnical Investigations Report
Document version: Revision B
1. Introduction
1.1. General
Sinclair Knight Merz (SKM) has been commissioned by Roads and
Maritime Services
(RMS) to undertake the concept design and prepare an environmental
assessment for
Pacific Highway (HW 10) and Wyong Road (MR335) intersection and
approaches
upgrade, Tuggerah NSW. The purpose of this Geotechnical
Investigation Report (GIR) is
to present the results of geotechnical investigations undertaken
and describe the
geotechnical model developed for the site.
This report has been prepared in accordance with Section 3.3.2.5 –
Geotechnical Report
(Geotechnical Investigation Report) as outlined in the Professional
Services Contract
(PSC) and SKM’s proposal for Consultancy Services for Contract
11.2911.1603.
The following Geotechnical Investigation Report (GIR) summarises
the scope of work
undertaken and the geotechnical investigation results and ground
models prepared for the
project.
1.2. Scope of work
The scope of work for the investigations and associated reporting
included the following
activities:
excavation, cone penetration tests, dynamic cone penetrometer
testing, and
laboratory testing.
Documenting the geotechnical information on the subsurface
conditions along the
proposed intersection and approaches upgrade.
Providing a summary of the laboratory test
result.
Preparation of a ground model for the project
alignment.
The site investigations were undertaken generally in accordance
with the Report on
Existing Geotechnical Information and Detailed Geotechnical
Investigations Proposal Plan
(SKM, 2012a) and the requirements as documented in the project’s
Review of
Environmental Factors (SKM, 2012b) and Environmental Management
Plan (SKM,
2012c).
Interpretation of the subsurface conditions and design
recommendations are provided
under a separate cover as documented in Pacific Highway (HW 10) and
Wyong Road
(MR 335) Intersection and Approaches Upgrade – Geotechnical Design
Report (SKM,
2012d).
Section 3 Summarises the desktop study undertaken.
Section 4 Describes the scope of geotechnical investigations
undertaken.
Section 5 Presents the geotechnical investigation
results.
Section 6 Summarises the geotechnical model and subsurface
conditions encountered.
Section 7 Provides a list of the referenced information used
in the GIR.
2. Project appreciation
The Pacific Highway and Wyong Road intersection is currently a four
leg dual lane
circulating roundabout. The Pacific Highway forms the northern and
southern legs of the
intersection while Wyong Road forms the eastern and western legs.
The roundabout
provides a main connection between the F3 freeway and The Entrance,
carrying about
52,000 vehicle movements per day in total, 34,800 vehicles on Wyong
Road and 29,900
vehicles on the Pacific Highway.
The Pacific Highway to the south of Wyong Road between Ourimbah and
Tuggerah was
declassified in April 2010 from State road, and is now a local road
under the care of
Wyong Shire Council. The key features of the project
include:
Replacement of the existing roundabout with a set of traffic
signals to enable better
management of the traffic volumes at this intersection.
A new rail overbridge over the Main Northern Railway
Line to accommodate
eastbound movements along Wyong Road. The existing Tuggerah Rail
Overbridge
will accommodate all westbound movements, including turning lanes
to the Pacific
highway (north).
Widening of the intersection to accommodate extra lanes in
all four directions and tie
in with the recently completed Pacific Highway Upgrade, Tuggerah
Straight, north of
the intersection at Anzac Road.
At-grade pedestrian crossings on all four legs of the
intersection.
Extension of the existing pedestrian underpass including
improvement of the general
amenity of the underpass facility.
Extension of the pedestrian/cyclist shared path network to
improve off-road
pedestrian/cyclist connections to adjacent areas including:
Tuggerah Railway Station,
Tuggerah Supa Centa, Tuggerah Business Park and Westfield Shopping
Centre.
The upgrade of the intersection of Wyong Road and Gavenlock
Road to incorporate
an additional left turn slip lane into Gavenlock Road
(southbound).
Retaining walls on: the northern side of Wyong Road (east
and west of the
intersection), the southern side of Wyong Road (east of the
intersection) and the
western side of Pacific Highway (north of the intersection).
Relocation of underground and overhead utilities to
accommodate the proposed
works.
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The current 80% concept design drawings for the bridge widening and
retaining walls are
included in Appendix B. The key structural and civil components of
the project where
geotechnical investigations have been targeted include the
following:
Retaining Walls:
- RW-A: reinforced Concrete ‘L’ Shaped Wall and associated
footprint for embankment. Up to 5.0 m in height and 380 m in
length.
- RW-B1 A, B1-B and RW-B2, Reinforced earth wall and associated
footprint for embankment. Up to 10 m in height, 80 and 260 and 30 m
in length respectively.
- RW-D: ‘L’ Shaped Wall and associated footprint for embankment. Up
to 3.0 m in height and 110 m in length.
- RW-C: Cast in-situ or precast wall supported on bored piles and
associated footprint for embankment. Up to 4.0 m in height and 80 m
in length
3.1. Sources of information
A review of the available background information relevant to
the project (provided by
RMS) and published maps has been undertaken to assess the likely
ground conditions in
the vicinity of the proposed works. The information obtained for
this review was used to
support the assessment and interpretation of the geotechnical field
investigation results
specifically carried out for this project. Background geotechnical
information reviewed
included:
- Gosford – Lake Macquarie 1:100 000 Geological Series Sheet
9131 & 9231,
provisional first edition 2003 and Notes (GSNSW, 2003).
- Gosford – Lake Macquarie 1:100 000 Soil Landscape Sheet
9131 - 9231, first
edition 1993 and Notes (Murphy, 1993).
- Australian Soil Resource Information System (CSIRO,
2006).
- NSW Natural Resource Atlas (DNR, 2012).
RMS Pavement Design Reports including:
- Pavement Design Report: Tuggerah Intersection Improvement
Pavement
Investigation, Hunter Region Geotechnical Services, Report No.
2523/01 (RMS,
2006).
- Pavement Design Report: Tuggerah Intersection Improvement –
Stage 2 East of
Rail Over Bridge, Hunter Region Geotechnical Services, Report No.
2523/02
(RMS, 2008).
DMR Drawings - Bridge over Main Northern Railway Line near
Tuggerah, Registration
Number: 0335 505 BC 0914, Sheet 1 to 4 (DMR, 1984).
The document references are included in Section 7.0, with select
information from these
references relevant to the project included in Appendix
B.
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3.2. Soils and geology
An understanding of the soils and geology for the area
surrounding the Pacific Highway
and Wyong Road intersection has been based on the 1:100 000
geological map published
by the NSW Geological Survey for Gosford – Lake Macquarie and
the 1:100 000 soil
landscapes of the Gosford – Lake Macquarie map published by Soil
Conservation Service
of NSW. Based on this mapping, the Woodburys Bridge and Wyong Soil
Landscape soil
landscape units are located within the project area and are
expected to be underlain by
the Tuggerah Formation which belongs to the Clifton Sub-Group
Formation of early
Triassic geological age (about 250 million years ago).
A description of the geological formations and soil
landscapes underlying the project are
provided in Table 3.1and illustrated in Appendix B (Figure B1).
These units were
confirmed during the geotechnical field investigations.
Figure 3.1 – geology extract (GSNSW, 2003)
PROJECT
LOCATION
Unit Description
(Residual soil)
The Woodburys Bridge soil landscape is characterised by gently
undulating rises to rolling low hills with local relief less than
80 metres and slope gradients less than 20 percent. Landforms
include broad crests, long and gently inclined slopes, and narrow
drainage lines. There are two main types of soils within this unit
that include deep red podzolic soils with some soloths in poorly
drained areas on claystone bedrock and shallow to moderately deep
yellow podzolic soils on sandstone bedrock.
(wy) Wyong
(Alluvial deposit)
The Wyong soil landscape is characterised by broad poorly drained
deltaic flood plains and alluvial flats of Quaternary sediments
with local relief less than ten metres and slope gradients less
than three percent. Landforms include meander scrolls, oxbows, and
swamps. Soils within this unit typically include brownish black
pedal loam overlying mottled brownish grey clay. Occasionally the
associated soil material bleached greyish yellow brown to dull
yellow orange sandy clay loam occurs at the interface between
materials. Splays and lenses of sand can occur in the soil
profile.
(Rnu) Tuggerah Formation
The Tuggerah formation is primarily a lower sequence in the Clifton
sub- group from the Early Triassic Period. It is comprised of red,
green, and grey shale and quartz-lithic sandstone with minor
claystones and conglomerate. The Clifton sub- group forms part of
the Narrabeen group from Triassic Period of the Mesozoic Era.
3.3. Acid Sulfate Soil (ASS) assessment
Acid sulfate soils (ASS) are soils and sediments containing
iron sulphides that, when
disturbed and exposed to oxygen, generate sulfuric acid and toxic
quantities of aluminium
and other heavy metals. The sulfuric acid and heavy metals are
produced in forms that
can be readily released into the environment, with potential
adverse effects on the natural
and built environment and human health. The majority of ASS are
formed by natural
processes under specific environmental conditions. This generally
limits their occurrence
to low lying sections of coastal floodplains, rivers and creeks
where surface elevations are
typically less than about 5m AHD.
A review of the online ASS maps ( Australian Soil
Resource Information System, CSIRO,
2006) for the project area was undertaken to assess the risk of
encountering ASS along
the intersection and upgrade alignment. Mapping indicates that the
likelihood of ASS is
considered “Low” probability. However, acid sulfate soils have been
encountered with
previous projects in low lying areas (similar to areas of this
alignment) to the north and
north east of the site.
ASS testing undertaken as part of the project (refer to
Section 5.1.2), did indicate that
there was a presence for Potential Acid Sulfate Soils (PASS),
within the lower lying
alluvial soil units.
3.4. Groundwater
The NSW Department of Natural Resources natural resource
atlas (DNR, 2012) provides
a database of registered groundwater bores within NSW. A search of
the groundwater
bore database identified two (2) groundwater bores with available
information located
within a 500 metre radius of the project site. Table
3.2 outlines a summary of the
groundwater bore information available from the natural resources
atlas.
Table 3.2 – Summary of groundwater bores
Location ID
Depth (m)
39.00 – 43.00 Shale (red)
43.00 – 61.00 Sandstone (grey)
3.5. Existing Rail Overbridge Drawings
Drawings for the existing bridge over the Main Northern Railway
line are included in
Appendix B and referenced above (DMR, 1984). Based on these
drawings, founding
levels (Contract Levels) for the existing rail overbridge were
designed at between RL–
10.0m AHD and RL–14.0m AHD, likely founded on rock. The drawings
indicate 400mm
square precast concrete driven piles were proposed. Work as
Executed information was
not provided for the driven piles.
Four relevant boreholes within the footprint of the existing bridge
pier and abutment
locations were included on Sheets 3 and 4 of the drawing set.
Detailed borehole logs were
not provided, however Standard Penetration testing information is
included which
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depth, with weathered to competent rock encountered at the depths
as summarised in
Table 3.3.
Table 3.3 – Summary of borehole rock levels
Borehole ID Surface Level (m AHD) Depth to top of Rock (m) Top of
Rock (mAHD)
Bore 1 4.5 17.5 - 13.0
Bore 2 3.9 17.0 - 13.1
Bore 6 4.8 18.8 - 14.0
Bore 7 4.9 18.8 - 13.9
Note: (1) m AHD = metres Australian Height Datum
3.6. Previous geotechnical investigations
3.6.1. RMS pavement investigation: 2523/01
RMS conducted a pavement investigation at the intersection between
HW10 the Pacific
Highway and MR335 Wyong Road, Tuggerah from 12 September 2006 to 13
September
2006. The investigation was undertaken to determine the subsurface
conditions and
provide recommended pavement designs for the proposed intersection
improvements.
The investigation consisted of thirteen (13) test holes with
Dynamic Cone Penetrometer
(DCP) tests, seventeen (17) Asphalt Concrete (AC) cores, detailed
pavement logging, and
pavement sampling. The test holes were excavated using a 400 mm
auger mounted on a
backhoe with DCP testing conducted in the test holes where
sub-grade conditions
permitted. The investigation location plan is presented in Appendix
B.
The RMS investigation results are outlined in Table 3.4 and
summarised as follows:
The existing pavement surface condition is variable, ranging
from fair condition in
most areas to poor condition at roundabouts.
The AC thickness from the cored samples ranged from 60mm to
235mm with typical
thickness from 60mm to 110mm. The AC condition was generally
described as fair
except where the AC was thinnest. In these areas it was described
as poor.
Fill materials encountered in the pavement were variable but
typically consisted of
high strength silty and clayey gravels and medium strength sandy
silts and clays with
pockets of low strength/high swell clays. The DCP results indicated
that the fill
material was generally well compacted and of high strength
in-situ.
Subgrade conditions also varied considerably with materials
encountered including
dense silty sand, low strength silty clay, inferred zones of low
compaction and/or high
moisture content from DCP results.
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A design CBR of five percent was recommended for the
proposed intersection
improvements.
Laboratory Test Quantity
2523.05 2 - 1 2 2 -
2523.06 1 - 1 1 1 -
2523.07 - 2 1 1 1 1 -
2523.08 3 2 2 1 1 -
2523.09 1 - - 1 1 1
2523.10 1 - 1 1 1 1
2523.11 2 1 2 1 1 -
2523.12 - 2 2 2 - - -
2523.14 - - - - - - - -
2523.15 - - - - - - - -
2523.16 - - - - - - - -
2523.17 - - - - - - - -
Note: (1) AC – Asphalt Concrete; DCP – Dynamic Cone Penetrometer;
MC – Moisture Content; PSD – Particle Size
Distribution; MDD – Maximum Dry Density; OMC – Optimum Moisture
Content; CBR – California Bearing Ratio; ASS – Acid
Sulfate Soil
RMS conducted a pavement investigation for the proposed embankment
widening located
east of the rail over bridge at the intersection between HW10 the
Pacific Highway and
MR335 Wyong Road, Tuggerah on 12 February 2008. The investigation
was undertaken
to determine the subsurface conditions and provide recommended
pavement designs for
the proposed intersection improvements.
The investigation consisted of four (4) test holes with DCP tests,
six (6) AC cores, detailed
pavement logging, and pavement sampling. The test holes were
excavated using a
450mm auger mounted on a backhoe with DCP testing conducted in the
test holes where
subgrade conditions permitted. The investigation location plan is
presented in Appendix
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The existing pavement condition encountered was described as
fair to good.
AC cored thickness from recovered samples ranged from
245mm to 265mm and was
described as fair to good condition.
Fill material encountered consisted of gravely sand, clayey
sand and sandy clay with
low plasticity and CBR values ranging from 11 to 14 percent. The
DCP results
indicated the fill material was well compacted.
The embankment foundation materials/subgrade materials
consisted of up to 650mm
of silty and sandy clay fill over silty clay. The DCP and hand
penetrometer results
indicated these materials were generally stiff up to 2m
depth.
A design CBR of five percent was recommended for the
intersection improvements.
Table 3.5 – Summary of pavement investigation 2523/02 from
2008
Laboratory Test Quantity
2523.202 1 - 1 - - -
2523.203 1 - 1 - - -
2523.205 - - - - - - - -
2523.206 - - - - - - - -
Note: (1) AC – Asphalt Concrete; DCP – Dynamic Cone Penetrometer;
MC – Moisture Content; PSD –
Particle Size Distribution; MDD – Maximum Dry Density; OMC –
Optimum Moisture Content; CBR – California
Bearing Ratio; ASS – Acid Sulfate Soil.
3.7. Site visit and inspection
A site inspection of the intersection and approaches upgrade
alignment was undertaken
by Scott Raynsford (Principal Geotechnical Engineer), David Andrew
(Geotechnical
Engineer), and Amanda Hunter (Environmental Scientist) from SKM on
Tuesday 24
January 2012 to assess the general site conditions, access issues,
traffic management
requirements, contamination issues and gain an appreciation of the
site geological and
topography features to assist in this assessment and planned site
investigation phase.
Results of the site inspection were used to develop a preliminary
ground model and
develop a geotechnical site investigation plan which was subject to
an Environmental
Assessment (SKM, 2012b) and an Environmental Management Plan
(SKM, 2012c) being
prepared and approved by RMS. Access to private land was also a key
consideration in
developing the site investigation plan. Select photographs from the
site inspection are
presented on Plates 1 to 12 in Appendix B.
4.1. General
Field geotechnical investigations were undertaken between 09 June
2012 and 09 August
2012 and involved the following components:
Borehole drilling.
levels.
Test pit excavation.
Geotechnical laboratory testing.
Table 4.1 provides a summary of the field investigations
conducted. The location of field
investigation works are displayed on the site investigation
location plan provided in
Appendix A.
Borehole 11 Assessment of sub surface conditions for proposed
alignment structures.
Cone Penetration Test 12 Assessment of soil strength/relative
density for deep alluvial deposits.
Test Pit 3 Assessment and sampling of subgrade
conditions
Dynamic Cone Penetrometer 3 Assessment of subgrade
consistency
4.2. Planning and approval
Prior to the commencement of the geotechnical investigation, SKM
was required to
prepare a number of project specific and quality assurance plans
for review and approval
by RMS and Railcorp. The geotechnical investigations were carried
out in accordance
with the following documents:
Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches
Upgrade: Report on Existing Geotechnical Information and
Detailed Geotechnical
Investigations Proposal Plan (SKM, 2012a).
Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches
Upgrade: Geotechnical Safety Plan (SKM, 2012e).
Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches
Upgrade: Geotechnical Investigations – EMP (SKM, 2012c).
Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches
Upgrade: Review of Environmental Factors (SKM, 2012b).
Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches
Upgrade: Method Statement – Geotechnical Site Investigation in Rail
Corridor (SKM,
2012f).
4.3. Borehole drilling
Two (2) boreholes were undertaken between 09 June 2012 and 10 June
2012 within the
rail corridor during a RailCorp track possession. The boreholes
were drilled by Terratest
Pty Ltd using a combination of a truck mounted Edson 3000 drill rig
(BH08) and a track
mounted Comacchio Geo 205 drill rig (BH09). Non Destructive
Drilling (NDD) using a
Vacmaster provided by Terratest Pty Ltd was employed for both
boreholes up to a
maximum depth of 1.5m below natural ground level to eliminate the
risk of underground
services. The boreholes were then drilled to depths between 25.3m
and 26.0m.
Nine (9) boreholes were undertaken between 23 July 2012 and 01
August 2012 by
Terratest Pty Ltd using a track mounted drill rig (Comacchio Geo
305). The boreholes
were drilled to depths between 6.5 m and 26.9 m. Three (3)
monitoring wells were
installed, with a summary of the construction details presented in
Section 4.3.1. The
borehole investigation locations are illustrated on the site
investigation location plan
contained in Appendix A.
The boreholes were logged on-site under full time supervision by an
SKM Geotechnical
Engineer who was responsible for locating the boreholes and
selecting locations for in-situ
testing and sampling. Where possible, water levels in the boreholes
were recorded during
the drilling process and are displayed on the borehole logs. Table
4.2 outlines a summary
of the borehole investigation locations and investigation
depths.
Boreholes were advanced through overburden soils by a combination
of 110mm diameter
continuous solid flight auger with a V-shaped or Tungsten Carbide
(TC) bit attachment to
refusal and washboring techniques. Standard Penetration Testing
(SPT) was undertaken
at regular intervals within the soil (typically 1m to 1.5m) to
assess the in-situ strength.
Steel casing was advanced to the top of rock and used to support
the overburden soil
during rock coring.
Boreholes were then continued through the rock profile using triple
tube NMLC diamond
coring techniques. The rock core recovered was logged and
photographed by an SKM
geotechnical engineer in accordance with current RMS methods and
Australian Standards
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are presented in Appendix C in combination with photographs
and explanatory notes for
geotechnical terms.
Environmental controls were implemented during the drilling program
in accordance with
the project specific EMP (SKM, 2012c) and utilised a combination of
geotextile filter cloth
and geofabric spill absorbents. The drill cuttings and fluid were
circulated during the
investigation and contained in the drilling tank. At the completion
of the investigation, the
borehole was reinstated using the generated spoil and cuttings
while the drilling fluids
were removed from site and disposed of at a licensed
facility.
Table 4.2 - Summary of borehole locations and investigation
depths
Location ID Total depth (m) Easting Northing Reduced level (m
AHD)
BH01 12.45 352801.9 6313404.1 3.98
BH02 10.00 352833.7 6313309.9 4.79
BH03 6.45 352634.4 6313309.2 12.36
BH04 6.45 352714.3 6313300.7 11.10
BH05 10.45 352766.6 6313297.4 8.22
BH07 22.10 352861.7 6313275.8 5.08
BH08 26.00 352874.7 6313232.3 4.77
BH09 25.30 352889.9 6313212.6 5.02
BH10 26.90 352925.2 6313181.0 5.03
BH11 23.95 352984.7 6313084.4 4.58
BH12 7.45 353032.1 6313017.1 4.36
4.3.1. Monitoring wells
Three (3) boreholes (BH07, BH10, and BH11) were selected to have
monitoring wells
installed for sampling, groundwater measurement purposes and
assessment of risks
associated with elevated groundwater levels and groundwater
aggressivity.
Each well was constructed using standard uPVC Class 18, 50mm
diameter, flush jointed,
screwed coupling casing and screens with 0.4mm slots. The screen
was placed towards
the bottom of the each well. The screened section was then
backfilled with 1 – 2mm
graded sand to approximately 0.5m above the screened section. This
was then overlain
by a bentonite seal and the well was then backfilled. A gatic cover
or monument was
installed at the surface.
The monitoring well construction details are summarised in Table
4.3 below and are
presented as monitoring well construction logs in Appendix C.
Location ID Surface RL
Total Drilled
Depth (m)
4.4. Cone Penetration Testing (CPTu) and Shear vane testing
(Su)
Cone penetration testing with pore pressure measurement was
undertaken at select
locations targeting the intersection and approaches upgrade for the
project. Twelve (12)
CPTu were conducted to depths from 6.6m to 21.4m below existing
ground level to
assess any potential layers of compressible soils and relative
density of alluvium units
underlying the project site.
The testing was undertaken by Network Geotechnics Pty Ltd using a
Geoprobe 6625CPT
track mounted rig with a 35mm diameter rod and conical tip that was
pushed vertically into
the soil profile to provide a continuous profile. Soil
characteristics including cone
resistance (qc), sleeve friction (f s), and pore pressure (u)
were measured every 0.02m by
load cells and strain gauges. A piezocone was used for all CPTu
tests to allow
measurement of porewater pressure and undertake dissipation
testing.
In-situ vane shear testing was completed at two (2) CPTu
investigation locations using
equipment mounted on the Geoprobe 6625CPT to provide an indication
of the peak in-situ
undrained shear strength. A remolded undrained shear strength test
was also undertaken
upon completion of the initial vane shear test.
Table 4.4 outlines a summary of the CPTu investigation
locations and investigation
depths and the CPT results sheets are included in Appendix C.
Table 4.4 - Summary of CPTu investigation locations
Location ID
Total depth
4.5. Test pits
The test pit excavations were carried out on 09 August 2012 for
sampling of sub-grade
materials and determination of excavation conditions and any
unsuitable material. A total
of three (3) test pits were excavated using a rubber tracked Kubota
U45-3 excavator to
depths ranging from 2.50m to 3.20m and terminated at the machine
limit of reach or limit
of sidewall stability. A summary of the test pit investigation
depths and locations are
provided in Table 4.5.
The test pits were logged on-site under full time supervision by an
SKM Geotechnical
Engineer who was responsible for locating test pits, sampling
disturbed material and
photographing the sub-surface profile. Test pit logs, photographs
and explanatory notes
for geotechnical terms are presented in Appendix C.
Each test pit was backfilled on completion with the excavated
material usually replaced in
the same sequence as it was excavated. The material was compacted
using the
excavator bucket and track rolled with each test pit left slightly
mounded to limit future
settlement of the ground surface.
Dynamic cone penetrometer testing in accordance with AS 1289.6.3.2
was undertaken
adjacent to each test pit to assess the in-situ strength/relative
density of the sub-surface
soils. The number of blows was recorded for successive penetrations
of 100mm up to
depths of 3.20m or prior refusal. Results from the DCP tests are
shown on the test pit logs
and the result sheets contained in Appendix C.
Table 4.5 - Test pit locations and investigation
depths
Location ID Total depth (m) Easting Northing Reduced level (m
AHD)
4.6. Laboratory testing
Laboratory tests were conducted on selected soil and rock samples
retrieved from
boreholes and test pits to assess the engineering characteristics
of the material. The
samples including undisturbed, disturbed, bulk, and environmental
soil samples and
recovered rock core were submitted to selected laboratories for the
type and quantity of
testing as outlined in Table 4.6.
Laboratory testing was performed using NATA registered laboratories
in accordance with
the relevant RMS test method or Australian Standard, where no RMS
test method applied.
A combination of SGS Australia Pty Ltd and Envirolab Services
Pty Ltd were used with the
subsequent laboratory test certificates presented in Appendix
D.
Table 4.6 – Summary of laboratory testing
Test Test Method Quantity Notes Sample Type
Geotechnical
for material assessment Disturbed, Bulk,
SPT
for material assessment Bulk, SPT
Particle size distribution
Undisturbed, Bulk
for material assessment
Undisturbed, Disturbed, Bulk,
Bulk
RMS T111 4 General classification of soils
for earthwork material assessment
Triaxial compression test
AS 1289 6.4.2 3 Strength properties of soil Undisturbed
Acid sulfate soil Rayment/ Higginson 22 Acid sulfate soil
assessment SPT, Disturbed
pH, sulphate (S04), chloride (Cl)
AS 1012.20 6 Aggressivity Disturbed
Resistivity AS 1289.4.4.1/RMS 6 Resistivity of soil Disturbed
Conductivity APHA 2510B 6 Conductivity of soil Disturbed
Point load index RMS T223 20 Rock mass strength
assessment Core
Compressive Strength (UCS)
AS 1012.20 3 Groundwater aggressivity Water
Conductivity APHA 2510B 3 Groundwater conductivity Water
4.7. Survey
On completion of the field investigations, the position and reduced
level for each test
location was surveyed using Global Positioning System (GPS)
technology. The survey
was conducted using a Real Time Kinematic (RTK) GPS with base
station, to an accuracy
of +/- 0.05m. The positions were recorded with reference to Map
Grid Australia 56 (MGA
56) and the reduced level with reference to Australian Height Datum
(AHD). The survey of
geotechnical investigation locations was undertaken by ADW Johnson
Pty Ltd who were
engaged by RMS.
The surveyed positions of the field investigation locations are
annotated on the respective
engineering log sheets contained in Appendix C and are shown
on the site investigation
location plan in Appendix A.
5.1. Laboratory testing
5.1.1. Mechanical
Soil classification
Fourteen (14) undisturbed, disturbed, SPT and bulk samples
collected during the field
investigations were analysed in the laboratory for general soil
classification and plasticity.
The results are displayed in Table 5.1 and the laboratory test
certificates are presented in
Appendix D.
Location ID
BH03 1.70 – 2.50 Clayey Sand 14.0 26 10 16
BH04 3.50 Silty Clay 17.6 63 19 44
BH10 2.50 Clayey Sand 11.8 25 15 10
BH10 14.50 Silty Clay 31.0 49 18 31
BH11 14.50 Silty Clay - 55 20 35
BH11 17.50 Silty Clay - 52 24 28
BH12 3.00 Silty Clay - 56 17 39
BH12 7.00 Clayey Sand 16.7 24 11 13
TP01 0.60 Gravelly Clay 11.6 32 17 15
TP01 1.30 Silty Clayey Sandy Gravel 10.3 35 10 25
TP02 0.60 Gravelly Silty Clay 17.4 35 13 22
TP02 1.90 Silty Clayey Sand 22.3 25 15 10
TP03 1.30 Silty Clayey Sand 19.6 30 13 17
Particle size distribution
A total of Nine (9) undisturbed, SPT, and bulk samples
collected during the field
investigations were subjected to laboratory analysis for particle
size distribution. The
results are outlined in Table 5.2 with the laboratory test
certificates contained in
Appendix D.
BH01 5.00 Silty Clay 52 45 3 -
BH03 1.70 – 2.50 Clayey Sand 33 58 9
BH10 7.00 Sand 10 90 -
BH11 14.50 Silty Clay 49 49 2 -
BH11 17.50 Silty Clay 41 58 1 -
BH12 3.00 Silty Clay 52 22 26 -
TP01 1.30 Silty Clayey Sandy Gravel 28 17 24 31
TP02 1.90 Silty Clayey Sand 19 16 62 3
TP03 1.30 Silty Clayey Sand 18 20 62 -
California Bearing Ratio (CBR)
A total of four (4) bulk samples collected from the test pit
excavations and borehole drilling
during field investigations were subjected to CBR testing that
evaluated compaction
properties and the soaked CBR (10 day). The soil samples were
compacted (standard
compaction) to 100 percent dry density ratio at the optimum
moisture content of the
material. The results of the CBR tests are displayed in Table 5.4,
with the corresponding
laboratory test certificates contained in Appendix D.
Table 5.4 - Summary of CBR test results
Location ID
BH03 1.70 – 2.50 Clayey Sand 10.5 2.02 25.0 30.0 0.1
TP01 1.30 Silty Clayey Sandy Gravel 11.0 1.95 3.0 3.0 2.0
TP02 1.90 Silty Clayey Sand 13.5 1.82 6.0 8.0 0.4
TP03 1.30 Silty Clayey Sand 13.0 1.88 5.0 6.0 0.3
Note: (1) OMC = Optimum Moisture Content
(2) MDD = Maximum Dry Density
The results outlined in Table 5.4 indicate that the subgrade
conditions are variable and
reflective of the soil type sampled. An assessment of the pavement
subgrade conditions is
contained in the Geotechnical Design Report (SKM, 2012d).
Shear strength
Three (3) consolidated undrained triaxial compression tests were
undertaken on
undisturbed thin wall tube samples from the field investigations to
evaluate the shear
strength parameters. Table 5.5 outlines a summary of the
triaxial compression test results
Location ID
Depth (m)
Material Moisture
Consolidation
One dimensional consolidation testing was undertaken on four (4)
undisturbed thin wall
tube samples recovered during the field investigations to assess
the compressibility
characteristics. The laboratory test results are outlined in Table
5.6 with the
corresponding laboratory test certificates contained in Appendix
D.
Location ID
Depth (m)
800 – 200 - - - - - 5.3
200 - 50 - - - - - 3.7
800 – 200 - - - - - 11.3
200 - 50 - - - - - 8.8
800 – 200 - - - - - 11.8
200 - 50 - - - - - 9.7
800 – 200 - - - - - 6.5
200 - 50 - - - - - 5.1
Rock strength
Rock core samples retrieved from the boreholes were subject to
point load index testing
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23
units encountered. A total of twenty (20) core samples were
subjected to diametral and
axial point load index tests (orientated perpendicular and along
the core axis respectively)
and UCS testing. The laboratory results for the rock strength
testing are outlined in Table
5.7 with the laboratory test certificates presented in
Appendix D.
Table 5.7 - Summary of rock strength test results
Location ID Depth (m) Material Axial point load,
Is(50) (MPa) Diametral point load, Is(50) (MPa)
UCS
(MPa)
BH07 18.62 – 18.87 Sandstone 0.84 0.64 20.2
BH07 21.06 – 21.26 Claystone 0.78 0.91 -
BH08 20.73 – 20.87 Sandstone 1.02 0.95 -
BH08 21.61 – 21.81 Sandstone 2.46 1.76 35.6
BH08 22.78 – 22.93 Sandstone 2.21 1.52 -
BH08 23.82 – 24.00 Sandstone 2.78 1.54 -
BH08 24.85 – 25.00 Claystone 0.41 0.51 -
BH09 19.00 – 19.17 Sandstone 0.15 0.22 -
BH09 21.43 – 21.60 Sandstone 2.31 2.08 -
BH09 22.73 – 22.90 Sandstone 0.94 0.97 -
BH09 23.79 – 24.00 Claystone 0.43 0.43 -
BH09 24.72 – 24.92 Claystone 0.54 0.37 6.6
BH10 19.47 – 19.65 Claystone 0.11 0.15 -
BH10 21.75 – 21.95 Claystone 0.07 0.13 -
BH10 23.68 – 23.81 Sandstone 0.81 0.85
BH10 24.06 – 24.22 Sandstone 0.72 0.17 -
BH10 25.08 – 25.32 Sandstone 0.58 0.49 22.5
5.1.2. Chemical
Aggressivity
A total of six (6) soil samples collected from the field
investigations were tested in the
laboratory for aggressivity using pH, chloride and sulphate
content, resistivity, and
conductivity. The samples were tested at various locations and
depths corresponding to
buried concrete and steel structures that include piles and bridge
abutments. The results
of soil aggressivity testing are outlined in Table 5.8.
Location ID
Sulphate Content (mg/kg)
Resistivity ( m)
BH01 6.00 6.3 25 16 190 51
BH02 7.00 6.2 130 36 76 130
BH05 4.00 6.5 110 33 120 84
BH07 5.50 5.9 170 110 55 180
BH10 10.00 4.3 20 1200 24 430
BH12 2.00 4.9 21 89 180 55
The results indicate variable pH values (4.3 to 6.5), low chloride
(20 to 170 mg/kg) and
sulphate (16 to 1200 mg/kg), variable resistivity values (24 to 190
m), and conductivity
values (51 to 430 µs/cm) for the soil samples tested.
A total of three (3) water samples collected from monitoring
wells installed during the field
investigations were tested in the laboratory for aggressivity using
pH, chloride and
sulphate content, and conductivity. Following well development, a
water sample was
retrieved from each piezometer to assess the influence of
groundwater on buried concrete
and steel structures. The results of the water aggressivity testing
are outlined in Table 5.9.
Table 5.9 – Water aggressivity test results
Location ID pH Chloride Content (mg/kg) Sulphate Content (mg/kg)
Conductivity (μS/cm)
BH07 7.2 260 64 1500
BH10 7.2 250 51 1600
BH11 5.9 34 12 160
The results indicate variable pH values (5.9 to 7.2), very low to
low chloride (34 to 260 mg/kg) and sulphate (12 to 64 mg/kg) and
variable conductivity values (160 to 1600 m) for the water
samples tested.
Acid sulfate soil (ASS)
Location ID Depth (m) pHF pHFOX Δ pH Reaction
Rate
BH01 1.00 5.0 3.8 1.2 Slight
BH01 3.00 5.1 3.7 1.4 Slight
BH02 3.00 5.7 3.5 2.2 Slight
BH02 4.00 4.3 4.1 0.2 Slight
BH02 5.00 5.1 2.8 2.3 Slight
BH02 5.50 5.8 4.3 1.5 Slight
BH07 4.00 5.3 4.0 1.3 Slight
BH08 1.80 5.6 3.0 2.6 Slight
BH08 2.00 5.3 3.4 1.9 Moderate
BH08 3.30 5.5 3.5 2.0 Slight
BH08 5.00 5.7 3.7 2.0 Slight
BH09 3.00 5.0 4.2 0.8 Slight
BH09 4.10 4.9 3.4 1.5 Slight
BH09 5.30 4.6 3.8 0.8 Slight
BH09 10.50 5.2 4.1 1.1 Slight
BH10 5.50 5.3 1.5 3.8 Vigorous
BH10 8.50 5.4 1.5 3.9 Vigorous
BH11 2.00 4.9 3.3 1.6 Vigorous
BH11 11.50 6.2 1.5 4.7
Moderate
BH11 23.50 6.1 2.1 4.0
Slight
BH12 1.70 4.6 2.7 1.9
Slight
BH12 4.70 5.1 3.6 1.5
Slight
Note: (1) pHF = Field pH
(2) PHFOX = Field peroxide pH
(3) ΔpH = Change in pH
Typical indicators from screening test results for Potential Acid
Sulfate Soils (PASS)
include pHFOX < 3, strong reaction rate, and a large change
from pHF to pHFOX. The
screening results do show indicators for potential ASS (PASS)
conditions. These samples
were selected for confirmation of ASS potential using Chromium
Suite analysis. The
Chromium Suite test is an acid base accounting approach widely used
for predicting net
acidity from the oxidation of sulphides present in ASS, and has the
advantage of not being
subjected to significant interferences from the sulphur in either
organic matter or sulfate
of Potential Sulfidic Acidity (SCR), Existing Acidity (Actual
Acidity [STAA] + Retained Acidity
[SNAS]) and Acid Neutralising Capacity (S ANC). The results of
the testing are summarised
in Table 5.11.
Location ID
Sample Depth
(m) pHKCL
SCR (%S)
(%s) Action Criteria
BH01 1.00 4.1 <0.005 0.05 <0.005 <0.05 0.05 ≥ 0.03
(exceeds action criteria)
BH01 3.00 4.1 <0.005 0.04 <0.005 <0.05 0.04 ≥ 0.03
(exceeds action criteria)
BH02 5.00 4.5 <0.005 0.03 <0.005 <0.05 0.03 ≥ 0.03
(exceeds action criteria)
BH07 4.00 4.6 <0.005 0.02 NT <0.05 0.02 -
BH08 1.80 4.5 0.02 0.02 NT <0.05 0.04 ≥ 0.03 (exceeds
action criteria)
BH09 4.10 4.1 <0.005 0.04 <0.005 <0.05 0.04 ≥ 0.03
(exceeds action criteria)
BH10 5.50 4.4 0.11 0.02 0.006 <0.05 0.14 ≥ 0.03 (exceeds
action criteria)
BH10 8.50 4.5 0.13 0.02 0.007 <0.05 0.15 ≥ 0.03 (exceeds
action criteria)
BH11 2.00 3.8 <0.005 0.08 <0.005 <0.05 0.08 ≥ 0.03
(exceeds action criteria)
BH11 11.50 4.5 0.04 0.04 <0.005 <0.05 0.08 ≥ 0.03
(exceeds action criteria)
BH12 1.70 4.1 <0.005 0.04 <0.005 <0.05 0.05 ≥ 0.03
(exceeds action criteria)
Note: (1) Exceeds action criteria (>0.03 % S, greater than 1000
tonnes) – Table 4.4 (Ahern. Et al, 1998)
(2) pHKCL = Potassium chloride pH
(3) SCR = Chromium reducible sulphur
(4) STAA = Titratable actual acidity
(5) SNAS = net acid soluble sulphur
(6) S ANC = Acid neutralising capacity
(7) NT = Not tested
The results above were compared against the action criteria (ASSAG,
1998), which
indicate that there is the potential for PASS soils at the site,
where most samples recorded
the net acidity and the Chromium reducible sulphur levels greater
than the action criteria.
Most samples tested recorded levels greater that the action
criteria outlined by Ahern et
al. Recommendations for management and handling of ASS are included
under a
separate cover in the Geotechnical Design Report (SKM, 2012d) for
consideration where
soils are to be disturbed below the groundwater table.
5.2. Groundwater observations
Groundwater level measurements were undertaken at all geotechnical
investigation
locations where free groundwater or seepage was observed. A summary
of the
groundwater level observations recorded during the site
investigations are outlined in
Table 5.12.
Location ID Surface RL
Water Level (m AHD)
Note: (1) m AHD = Metres Australian Height Datum
(2) m bgl = Metres Below Ground Level
Following piezometer installation and well development, groundwater
monitoring was
undertaken at each well location to determine the groundwater
level. Table 5.13 outlines
the groundwater level measurement that was observed.
Table 5.13 – Monitoring well observation levels
Location ID Surface RL
Water Level (m bTOC)
5.3. Field testing
Standard penetration testing was undertaken at all borehole
investigation locations in the
overburden soils. The standard penetration test results have been
illustrated in Figure 5.1
against the corresponding depth.
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28
Figure 5.1 – SPT results
In-situ vane shear test
In-situ vane shear testing was undertaken at two (2) CPTu
investigation locations to
assess the in-situ shear strength, provide calibration with CPTu
results for development of
the geotechnical model. Table 5.14 provides a summary of the insitu
vane shear test
results.
Table 5.14 – Summary of in-situ vane shear test
results
Location ID Depth (m) Shear strength (KPa) Remoulded shear strength
(KPa)
CPT05 2.00 30.36 16.66
CPT11 2.70 71.80 14.41
D e p
t h
( m
A H
D )
SPT N Value
The geotechnical investigation for the project has been undertaken
to characterise the
subsurface conditions into geotechnical units. These geotechnical
units were established
from the available background geotechnical information as well as
from the results of the
boreholes, CPTu, test pits and laboratory test data.
Table 6.1 outlines the geotechnical units developed for the
project. The soil units have
been separated into fill, alluvial, residual soil. Rock units have
been classified based on
stratigraphy, strength and weathering characteristics. The inferred
subsurface profile is
presented on the geotechnical section included in Appendix F and
provides the inferred
boundaries between units.
Soils (wy) Wyong (Alluvial deposits)
Geology (Rnu) Tuggerah Formation
Material description
N/A New fill areas and existing embankment construction.
1B Fill BH03, BH08, BH09, TP02
Existing fill materials and topsoil. Typically firm to stiff clay
with some gravel inclusions. Limited fill was encountered in the
boreholes, predominately localised.
Alluvial deposits (sands/silty sands)
2A Sands/silty sand (loose)
CPT03, CPT09, TP01 – TP03
Sands and silty sands. Typically loose, medium grained, with some
silt and clay banding.
2B Sands/silty sand (medium dense)
Sand and silty sand (medium dense), Typically medium dense, medium
grained with some silt and clay lenses.
2C Sands/silty sand (dense to very dense)
Sand/silty sand (dense to very dense), Typically dense to very
dense, medium grained with some silt and clay lenses.
Alluvial deposits (clays/silty clays)
BH12, CPT03 – CPT05, CPT09
– CPT11, TP03
Clays and Silts. Soft to firm, typically firm with some localised
soft areas, high plasticity with some sand and silty sand
lenses.
2F Clays/Silts (very stiff to hard)
Clays and Silts. Typically very stiff to hard, high plasticity with
some sand and silty sand lenses.
Residual soil (clays/silty clays)
, BH01 – BH05, BH07 – BH10,
CPT01 – CPT04
Clays and Silty Clays, typically very stiff to hard, high
plasticity, residual soil.
Bedrock
(Class V) Claystone, typically extremely low strength,
extremely to highly weathered to residual soil material.
4B Claystone (Class IV) Claystone, typically very low to low
strength, highly weathered, fractured
4C Sandstone/
Siltstone
(Class III) Sandstone and bands of claystone, typically medium
to high strength, moderately weathered, fractured.
Note: (1) m AHD = Metres Australian Height Datum
(2) A classification of the rock-mass has also been provided which
has generally been undertaken in accordance with
the guidelines presented in “Foundations on Sandstone and Shales in
the Sydney Basin” (Pells et al, 1998).
Interpretation of the subsurface conditions is provided under
separate cover as
documented in the project Geotechnical Design Report (SKM,
2012d).
6.2. Material properties of geotechnical units
6.2.1. (Unit 1) Fill
The fill (Unit 1) encountered along the Pacific Highway and Wyong
Road intersection and
approaches upgrade alignment was generally limited to areas
adjacent to existing road,
rail corridor, and subsequent pavement structures. Fill was
encountered in BH03, BH08,
BH09 and TP02 to depths between 0.60m and 1.20m and typically
comprised soft to stiff
sandy and silty clays. Soil classification test results for Unit 1
are illustrated on Figure 6.2.
6.2.2. (Unit 2) Alluvial deposits
The alluvial deposits (Unit 2) encountered across the project
alignment in: BH01, BH08–
BH12, CPT01–CPT05, CPT09–CPT11 and TP01–TP03 have been assessed
into six (6)
geotechnical units (2A to 2F) using soil classification and
consistency properties.
Figure 6.2 illustrates a plasticity chart with the soil
classification laboratory test results for
Unit 2. It can be seen that Unit 2A comprises low plasticity
material with liquid limits that
varied between 25 and 35 percent and plastic limit that varied
between 10 and 17 percent.
The corresponding plasticity index values ranged between 10 and 25
percent. Particle
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31
silty clays and clayey sands with the particle size distribution
curves illustrated in Figure
6.1.
Unit 2E and 2F are also outlined in Figure 6.1 and Figure 6.2,
with the laboratory test
results illustrating that the units typically comprise stiff (Unit
2E) to hard (Unit 2F) high
plasticity clays and silts. The liquid limits varied between 24 and
63 percent and plastic
limit that varied between 11 and 24 percent. The subsequent
plasticity index values
ranged between 13 and 44 percent.
Figure 6.1 - Particle size distribution test results
Figure 6.2 - Plasticity chart for soil classification test
results
California bearing ratio tests were carried out on four (4) bulk
samples retrieved from the
test pit excavations for Unit 2A. The results of the sub-grade for
Unit 2A indicated CBR
values typically ranging between 3 to 6 percent and swells ranging
between 0.1 to 2.0
percent. The bulk sample retrieved from BH03 reported a CBR value
of 25 percent,
however, this result is not considered representative and affected
by gravel inclusions.
The maximum dry density values ranged between 1.82 to 2.02 tonnes
per cubic metre
and the corresponding optimum moisture content varied between 10.5
and 13.5 percent.
Results from the testing, including compaction and CBR
characteristics are outlined on
Figure 6.3 and Figure 6.4.
1.50
1.60
1.70
1.80
1.90
2.00
2.10
M a
x
D r y
D e n
s i t y
( t /
m
0
5
10
15
20
25
30
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2
C B
R
( %
)
The laboratory test results for the consolidated undrained triaxial
compression tests
undertaken on Unit 2E are illustrated in Figure 6.5 and it
shows the p – q diagram for the
triaxial compression test results.
6.2.3. (Unit 3A) Residual soil
The residual soil (Unit 3A) encountered along the Pacific Highway
and Wyong Road
intersection and approaches upgrade alignment typically comprised
very stiff to hard clays
and silty clays. Residual soil was encountered in: BH01–BH05,
BH07–BH10 and CPT01–
CPT04 to depths between 2.70m and 13.80 m. Unit 3A is illustrated
on the subsurface
profile contained in Appendix A.
The laboratory test results for the consolidated undrained triaxial
compression tests
undertaken on Unit 3A are illustrated in Figure 6.5 and it
shows the p – q diagram for the
triaxial compression test results.
One dimensional consolidation testing was undertaking with the
oedometer test
certificates outlined in Appendix D. Figure 6.6 and Figure
6.7 illustrate the compression
ratio and the overconsolidation ratio against depth
respectively.
0
20
40
60
80
100
120
140
160
180
200
0 50 100 150 200 250 300 350 400 450
q '
( K
P a
0
2
4
6
8
10
12
14
16
18
20
D e p
t h
( m
)
Cc/(1 + e0)
D e p
t h
( m
)
Overconsolidation Ratio (OCR)
the Pacific Highway and Wyong Road intersection and approaches
upgrade alignment.
These units have been classified into three geotechnical units (4A,
4B, 4C) based on
stratigraphy and subsequently strength and defects in accordance
with the guidelines
presented in ‘Design Loadings for Foundations on Shale and
Sandstone in the Sydney
Region’ (Pells et al, 1978) and ‘Foundations on Sandstone and
Shale in the Sydney
Region’ (Pells et al, 1998). On this basis, allowing for some
variability, Unit 4A has been
classified as typically extremely low strength rock (Class V), Unit
4B classified as very low
to low strength rock (Class IV), and Unit 4C classified as
typically medium to high strength
rock (Class III). The inferred subsurface profile and rock unit
boundaries are presented on
the geotechnical section drawings in Appendix A.
Statistical analysis of the 20 point load index rock strength tests
and unconfined
compressive strength tests undertaken within Unit 4A, Unit 4B, and
Unit 4C has been
completed. The results summary from the rock strength statistical
analysis is presented in
Table 6.2 and Table 6.3. Figure 6.8 illustrates the axial
point load strength index results
against the average depth of the rock core sample tested.
Table 6.2 - Summary of UCS test data
Geotechnical unit
Table 6.3- Summary of point load index test data
Geotechnical unit
2.08 (diametral)
0.34 (axial)
0.17 (diametral)
1.14 (axial)
0.91 (diametral)
0.84 (axial)
0.57 (diametral)
Note: (1) Test completed includes both axial and diametral point
load index.
(2) Results are outlined in the table as axial / diametral.
Four (4) unconfined compressive strength tests (on as received
moisture) were
undertaken on core samples from Unit 4C in BH07–BH10 with results
as outlined in
Section 5.1.1. These values were compared with the corresponding
axial point load index
strength test results for the same core sample and the ratio of UCS
to Is(50) ranged from
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38
strength index test results for geotechnical Unit 4C along with the
established Sydney
Basin correlation (Pells, 2004).
Figure 6.8 - Summary of axial point load strength index test
results
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
D e p
t h
( m
Unit 4A Unit 4B Unit 4C
Figure 6.9 - UCS vs axial point load strength index
correlation
6.3. Interpretation of CPTu Data
The CPTu data obtained from the field testing have been used to
interpret geotechnical
layers (units) and to estimate engineering properties for the
geotechnical design. The
CPTu data was correlated against the empirical formulae to estimate
the engineering
properties for cohesive soils.
The two main parameters investigated were undrained shear strength
(Su) and Over
Consolidation Ratio (OCR).
The relationship between Su and cone resistance, qc, is
expressed as (Lunne et al., 1997):
Su = (qc – σ vo)/N k
Where Nk is an empirical factor
and σ vo is total overburden stress.
Nk of 15 was adopted
for this assessment.
The relationship between OCR and qc was adopted as
follows:
OCR = k (qt –
σ vo)/ σ ’vo
0.00
0.50
1.00
1.50
2.00
2.50
3.00
P o
d
I n
d e
x
I s
( 5
0
)
UCS = 20Is(50) Unit 4C
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40
k is an empirical factor and σ’vo is the effective
overburden stress, with a k of 0.2 adopted
for this assessment.
The profiles of Su and OCR are included in Appendix E. These plots
have been used to
7. References
Ahern C. R., Stone Y., and Blunden B. (1998), Acid
Sulfate Soils Assessment Guidelines,
published by the Acid Sulfate Soil Management Advisory Committee
(ASSMAC),
Wollongbar, NSW, Australia.
09/01/2012, http://www.asris.csiro.au/mapping/viewer.htm.
Department of Main Roads, NSW (1984), Bridge over Main
Northern Railway Line near
Tuggerah Sheet 1 to 4, Registration Number of Plans: 0335 505 BC
0914, Main Road No:
335, Shire of Wyong.
Department of Natural Resources (2012). NSW Natural Resource Atlas,
accessed
09/01/2012, http://www.nratlas.nsw.gov.au.
Geological Survey of New South Wales (2003), Gosford-Lake Macquarie
1:100 000
Geological Sheet 9131 - 9231, provisional edition, NSW Department
of Primary Industries,
Sydney.
Lunne, T, Robertson, P.K. and Powell, J.J.M. (1996), Cone
Penetration Testing in
Geotechnical Practice, 1st Edition, London, Chapman and Hall,
UK.
Murphy C. L., (1993), Soil Landscapes of the Gosford-Lake Macquarie
1:100 000 Sheet
map and report, Department of Conservation and Land Management,
Sydney.
Pells P. J. N., Douglas D. J., Rodway B., Thorne C., and McMahon B.
K. (1978), Design
Loadings for Foundations on Shale and Sandstone in the Sydney
Region , Australian
Geomechanics Journal, Vol. G8, Pages 31 – 39.
Pells P. J. N., Mostyn G. and Walker B. F. (1998), Foundations on
Sandstone and Shale
in the Sydney Region, Australian Geomechanics Journal, Vol. 33, No.
3, Pages 17 – 29.
Pells P. J. N. (2004), Substance and Mass Properties for the Design
of Engineering
Structures in the Hawkesbury Sandstone, Australian Geomechanics
Journal, Vol. 39, No.
3,Pages 1 – 22.
Improvement Pavement Investigation, Hunter Region Geotechnical
Services, Report No.
2523/01, dated 22 November 2006.
Roads and Maritime Services (2008), Pavement Design Report:
Tuggerah Intersection
Improvement – Stage 2 East of Rail Over Bridge, Hunter Region
Geotechnical Services,
Report No. 2523/02, dated 27 March 2008.
NB11462-ESG-RP-0002_B_Geotechnical Investigations Report.docx
42
Sinclair Knight Merz (2012a), Pacific Highway HW10 and Wyong Road
MR335
Intersection and Approaches Upgrade: Report on Existing
Geotechnical Information and
Detailed Geotechnical Investigations Proposal Plan ,
NB11462-ESG-RP-0001-B, 17
February 2012, Sydney.
Sinclair Knight Merz (2012b), Pacific Highway HW10 and Wyong Road
MR335
Intersection and Approaches Upgrade: Review of Environmental
Factors, EIA-P05-G02-
T03, 08 May 2012, Sydney.
Sinclair Knight Merz (2012c), Pacific Highway HW10 and Wyong Road
MR335
Intersection and Approaches Upgrade: Geotechnical Investigations –
Environmental
Management Plan, NB11462-NEM-PR-0002-D, 15 May 2012, Sydney.
Sinclair Knight Merz (2012d), Pacific Highway HW10 and Wyong Road
MR335
Intersection and Approaches Upgrade: Geotechnical Design Report,
NB11462-ESG-RP-
0003, 22 September 2012, Sydney.
Sinclair Knight Merz (2012e), Pacific Highway HW10 and Wyong Road
MR335
Intersection and Approaches Upgrade: Geotechnical Safety Plan,
NB11462-AAA-PL-
0003-A, 12 March 2012, Sydney.
Sinclair Knight Merz (2012f), Pacific Highway HW10 and Wyong Road
MR335
Intersection and Approaches Upgrade: Method Statement –
Geotechnical Site
Investigation, NB11462-ESG-RW-0001-D 30 May 2012, Sydney.
Standards Australia International (1993), Australian Standard
AS1726 – 1993,
Geotechnical Site Investigations, Sydney.
Testing Soils for Engineering Purposes, Sydney.
Standards Australia International (2005), Australian Standard
AS4133 – 2005 Methods of
Testing Rocks for Engineering Purposes, Sydney.
Standards Australia International (2009), Australian Standard
AS2159 – 2009 Piling –
Design and Installation, Sydney.
8. Limitations
The sole purpose of this report is to present the findings of a
geotechnical investigation
carried out by Sinclair Knight Merz (“SKM”) for the Roads and
Maritime Services of NSW
(RMS) in connection with Pacific Highway (HW 10) and Wyong Road (MR
335)
intersection and approaches upgrade. This report was produced in
accordance with and is
limited to the scope of services set out in the contract between
SKM and the RMS. That
scope of services, as described in this report, was developed with
the RMS.
Undertaking an assessment or study of on-site conditions may reduce
the potential for
exposure to the presence of inadequate bearing ground. All reports
and conclusions that
deal with sub-surface conditions are based on interpretation and
judgement and as a
result have uncertainty attached to them. You should be aware that
this report contains
interpretations and conclusions which are uncertain, due to the
nature of the
investigations. No study can completely eliminate risk, and even a
rigorous assessment
and/or sampling programme may not detect all problem areas within a
site.
This report is based on assumptions that the site conditions as
revealed through sampling
are indicative of conditions throughout the site. The findings are
the result of standard
assessment techniques used in accordance with normal practices and
standards, and (to
the best of SKM’s knowledge) they represent a reasonable
interpretation of the current
conditions on the site.
However, all sampling techniques, by definition, cannot determine
the conditions between
the sample points and so the report can only provide an indication
of, and cannot be taken
to be a full representation of, the sub-surface conditions. It is
an indication of the likely sub
surface conditions.
Conditions as encountered when site work commences may be different
from those SKM
infers based on its sampling techniques. It is important that SKM
is retained to review the
site conditions during site works to confirm and update any
assumptions made during the
preparation of this report.
The passage of time, manifestation of latent conditions or impacts
of future events may
require further examination of the project and subsequent data
analysis, and re-evaluation
of the data, findings, observations and conclusions expressed in
this report.
In preparing this report, SKM has relied upon, and presumed
accurate, any information (or
confirmation of the absence thereof) provided by the Client and
from other sources.
Except as otherwise stated in the report, SKM has not attempted to
verify the accuracy or
completeness of any such information. If the information is
subsequently determined to be
false, inaccurate or incomplete then it is possible that our
observations and conclusions as
expressed in this report may change.
NB11462-ESG-RP-0002_B_Geotechnical Investigations Report.docx
44
SKM has prepared this report in accordance with the usual care and
thoroughness of the
consulting profession, for the sole purpose described above and by
reference to
applicable standards, guidelines, procedures and practices at the
date of issue of this
report. For the reasons outlined above, however, no other warranty
or guarantee, whether
expressed or implied, is made as to the data, observations and
findings expressed in this
report, to the extent permitted by law.
This report does not address environmental or geo-environmental
issues including the
presence of any contaminants or hazardous materials at the site
unless SKM was
specifically and expressly retained to do so.
Except as specifically stated in this report, SKM makes no
statement or representation of
any kind concerning the suitability of the site for any purpose or
the permissibility of any
use. Use of the site for any purpose may require planning and other
approvals and, in
some cases, Environmental Protection Authority and accredited site
auditor approvals.
SKM offers no opinion as to the likelihood of obtaining any such
approvals, or the
conditions and obligations which such approvals may impose, which
may include the
requirement for additional environmental investigations and/or
works.
This report should be read in full and no excerpts are to be taken
as representative of the
findings. No responsibility is accepted by SKM for use of any part
of this report in any
other context.
This report has been prepared on behalf of, and for the exclusive
use of, SKM’s Client,
and is subject to, and issued in accordance with, the provisions of
the agreement between
SKM and its Client. SKM accepts no liability or responsibility
whatsoever for, or in respect
B2: As-built bridge drawings
B4: Site inspection photographs
!
m
LEGEND 10 metre contour (AHD)
Construction footprint
Soil Landcape
Figure B1 | Geology and soil landscape
NB11462: Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches Upgrade
Plate 1: View south east, adjacent to Anzac Road
Plate 2: View south, vegetation behind 8 Anzac Road, Tuggerah
Plate 3: View sou th west, vegetation behind 8 Anzac Road,
Tuggerah
Plate 4: View sou th, along Pacific Highway
NB11462: Pacific Highway HW10 and Wyong Road MR335 Intersection and
Approaches Upgrade
Plate 7: View north, vegetation and Wyong Road embankment
Plate 8: View north east, Pacific Highway and Tambelin Street
Intersection
Plate 9: View, bridge over railway Plate 10: View, bridge over
railway - eastern abutment
C1: Explanatory notes
C2: Borehole logs
0.80m
1.70m
4.20m
8.70m
Silty CLAY: Dark brown - grey, low plasticity, some fi ne grained
sand, trace fine angular to sub-angular gravel, trace organics,
moist, soft, topsoil.
Sandy CLAY: Brown mottled grey, low plasticity, fine to medium
grained sand, trace silt, wet, stiff, alluvium.
SAND: Pale grey mottled orange/brown, fine to medium grained, trace
silt, wet, medium dense, alluvium.
- As above, becoming pale grey mottled brown
- As above, becoming grey, with some clay
Silty CLAY: Grey/pale grey, high plasticity, trace fine grained
sand, wet, stiff, residual soil.
- As above, becoming pale grey mottled brown
- As above, becoming pale grey, very stiff
- As above, becoming hard
Silty CLAY: Pale grey mottled orange/dark red, high plasticity,
some ironstone inclusions, wet, hard, residual soil.
TOPSOIL
ALLUVIUM
RESIDUAL SOIL
G r o u
n d w a
t e r E
n c o u
n t e
r e d a
t 1
. 2
0 m
1.45m
2.45m
3.45m
4.45m
6.45m
7.45m
8.45m
9.45m
D
U50
5.45m
M o i s
t u r e
C o n
t e n
t
M O
I S T
U R E
CONSISTENCY /
RELATIVE DENSITY
S / L
D r y D
e n s
i t y
D R
I L L
I N G
&
W A T
E R
D E T
A I L
LAB DATA
L O G
A
t t e
r b e
r g
L i m
i t s
R L
( m )
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
Secondary and Minor Components
< 12 kPa {0-2}
12 - 25 {2-4}
25 - 50 {4-8}
50 - 100 {8-15}
100 - 200 {15-30}
> 200 kPa {>30}
DENSITY (N-value) CONSISTENCY (Su) {N-value}SAMPLES & FIELD
TESTS
MOISTURE CONDITION D = Dry M = Moist W = Wet
DRILLING D Disturbed Sample ES Env Soil Sample EW Env Water
Sample
SPT SPT Sample U Undisturbed Tube Sample W Water Sample
COMMENTS Field Test Data
& Other Observations
HP Hand Penetrometer HV Hand Vane Shear (P: Peak Su R:
Residual Su) N SPT blows per 300mm HW SPT penetration by hammer
weight RW SPT penetration by rod weight
HA Hand Auger AS Auger WB Washbore RR Rock
Rolling
GROUNDWATER SYMBOLS
= Water level (during drilling)
HQ HQ Coring NQ NQ Coring PQ PQ Coring NMLC NMLC Coring
RIG TYPE : Comacchio GEO 305 (track)
PROJECT : HW10 & MR335 Intersection Upgrade
POSITION : E: 352801, N: 6313404 ( MGA94)
PAGE : 1 OF 2
LOCATION : Tuggerah, NSW
STANDARD : AS 1726 - 1993DATE DRILLED : 26/7/12 to 26/7/12 LOGGED
BY : DA CHECKED BY : SRR
File: NB11462 BH01 Page 1 OF 2
JOB NO : NB11462
BH01HOLE NO:SOIL LOG
S K M
A G S
R E V
2 _
D A
S K M
S O
I L L
O G
N B 1
1 4 6
2 _
S O
I L
i n g
F
i l e
> > 2
4 / 0
8 / 2
0 1 2
1 5
: 5
4
12.10m
12.45m
Silty CLAY: Pale grey mottled orange/dark red, high plasticity,
some ironstone inclusions, wet, hard, residual soil.
(continued)
CLAYSTONE: Dark red, extremely weathered, extremely low
strength.
Borehole terminated at 12.45 m
RESIDUAL SOIL
BEDROCK
G r o u
n d w a
t e r E
n c o u
n t e
r e d a
t 1
. 2
0 m
10.95m
12.45m
M o i s
t u r e
C o n
t e n
t
M O
I S T
U R E
CONSISTENCY /
RELATIVE DENSITY
S / L
D r y D
e n s
i t y
D R
I L L
I N G
&
W A T
E R
D E T
A I L
LAB DATA
L O G
A
t t e
r b e
r g
L i m
i t s
R L
( m )
11.0
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
Secondary and Minor Components
< 12 kPa {0-2}
12 - 25 {2-4}
25 - 50 {4-8}
50 - 100 {8-15}
100 - 200 {15-30}
> 200 kPa {>30}
DENSITY (N-value) CONSISTENCY (Su) {N-value}SAMPLES & FIELD
TESTS
MOISTURE CONDITION D = Dry M = Moist W = Wet
DRILLING D Disturbed Sample ES Env Soil Sample EW Env Water
Sample
SPT SPT Sample U Undisturbed Tube Sample W Water Sample
COMMENTS Field Test Data
& Other Observations
HP Hand Penetrometer HV Hand Vane Shear (P: Peak Su R:
Residual Su) N SPT blows per 300mm HW SPT penetration by hammer
weight RW SPT penetration by rod weight
HA Hand Auger AS Auger WB Washbore RR Rock
Rolling
GROUNDWATER SYMBOLS
= Water level (during drilling)
HQ HQ Coring NQ NQ Coring PQ PQ Coring NMLC NMLC Coring
RIG TYPE : Comacchio GEO 305 (track)
PROJECT : HW10 & MR335 Intersection Upgrade
POSITION : E: 352801, N: 6313404 ( MGA94)
PAGE : 2 OF 2
LOCATION : Tuggerah, NSW
STANDARD : AS 1726 - 1993DATE DRILLED : 26/7/12 to 26/7/12 LOGGED
BY : DA CHECKED BY : SRR
File: NB11462 BH01 Page 2 OF 2
JOB NO : NB11462
BH01HOLE NO:SOIL LOG
S K M
A G S
R E V
2 _
D A
S K M
S O
I L L
O G
N B 1
1 4 6
2 _
S O
I L
i n g
F
i l e
> > 2
4 / 0
8 / 2
0 1 2
1 5
: 5
4
1.80m
5.60m
6.40m
10.00m
Silty CLAY: Dark grey mottled brown, medium plasticity, trace fine
grained sand, trace organics, moist, stiff.
- As above, becoming brown mottled pale grey
SAND: pale grey mottled orange/brown, fine to medium grained, trace
clay, wet, medium dense, alluvium.
- As above, becoming pale grey
Sandy CLAY: pale grey, medium plasticity, fine grained sand, some
sil t, wet, stiff, alluvium.
Silty CLAY: pale grey mottled dark red/orange, medium plasticity,
trace fine grained sand, moist, very stiff, residual soil.
- As above, becoming pale grey mottled orange, hard
Borehole terminated at 10.00 m
ALLUVIUM
9.70: No SPT at 10.00m, hole collapse to 7.50m
G r o u
n d w a
t e r E
n c o u
n t e
r e d a
t 2
. 6
0 m
1.45m
2.95m
4.45m
5.95m
7.45m
8.95m
D
D
D
M o i s
t u r e
C o n
t e n
t
M O
I S T
U R E
CONSISTENCY /
RELATIVE DENSITY
S / L
D r y D
e n s
i t y
D R
I L L
I N G
&
W A T
E R
D E T
A I L
LAB DATA
L O G
A
t t e
r b e
r g
L i m
i t s
R L
( m )
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
Secondary and Minor Components
< 12 kPa {0-2}
12 - 25 {2-4}
25 - 50 {4-8}
50 - 100 {8-15}
100 - 200 {15-30}
> 200 kPa {>30}
DENSITY (N-value) CONSISTENCY (Su) {N-value}SAMPLES & FIELD
TESTS
MOISTURE CONDITION D = Dry M = Moist W = Wet
DRILLING D Disturbed Sample ES Env Soil Sample EW Env Water
Sample
SPT SPT Sample U Undisturbed Tube Sample W Water Sample
COMMENTS Field Test Data
& Other Observations
HP Hand Penetrometer HV Hand Vane Shear (P: Peak Su R:
Residual Su) N SPT blows per 300mm HW SPT penetration by hammer
weight RW SPT penetration by rod weight
HA Hand Auger AS Auger WB Washbore RR Rock
Rolling
GROUNDWATER SYMBOLS
= Water level (during drilling)
HQ HQ Coring NQ NQ Coring PQ PQ Coring NMLC NMLC Coring
RIG TYPE : Comacchio GEO 305 (track)
PROJECT : HW10 & MR335 Intersection Upgrade
POSITION : E: 352834, N: 6313310 ( MGA94)
PAGE : 1 OF 1
LOCATION : Tuggerah, NSW
STANDARD : AS 1726 - 1993DATE DRILLED : 23/7/12 to 23/7/12 LOGGED
BY : DA CHECKED BY : SRR
File: NB11462 BH02 Page 1 OF 1
JOB NO : NB11462
BH02HOLE NO:SOIL LOG
S K M
A G S
R E V
2 _
D A
S K M
S O
I L L
O G
N B 1
1 4 6
2 _
S O
I L
i n g
F
i l e
> > 2
4 / 0
8 / 2
0 1 2
1 7
: 3
7
ASPHALT: Fine to coarse grained.
Gravelly SAND: Grey - pale grey, fine to coarse grained sand, fine
to medium angular to sub-angular gravel, dry, loose, fill.
Sandy CLAY: Pale brown, low plasticity, fine grained sand, trace
silt, trace fine sub-angular gravel, dry, soft, fill.
Silty SAND: Pale brown/dark grey, fine to medium grained, trace f
ine sub-angular gravel, dry to moist, loose.
Sandy CLAY: Pale brown/grey mottled orange/dark red, low
plasticity, fine to medium grained sand, trace fine sub-angular
gravel, dry to moist, stiff .
Silty CLAY: Pale grey mottled dark red/orange, high plasticity,
some f ine grained sand, some ironstone fragments up to 25mm, dry
to moist, very stiff, residual soil.
Sandy CLAY: Pale grey mottled orange/dark red, low plasticity, fine
to medium grained sand, dry to moist, hard, residual soil.
Borehole terminated at 6.45 m
ROAD SURFACE
RESIDUAL SOIL
G r o u
n d w a
t e r N
o t E n
c o u n
t e r e
d
1.00m
2.00m
2.80m
3.00m
4.00m
5.00m
6.00m
1.45m
2.45m
3.45m
4.45m
5.45m
6.45m
D
M o i s
t u r e
C o n
t e n
t
M O
I S T
U R &nbs