Edition 2 / Revision 1 TRANSPORT FOR NSW June 2020 TRANSPORT FOR NSW (TfNSW) SPECIFICATION GUIDE NR44 GUIDE TO QA SPECIFICATION R44 EARTHWORKS REVISION REGISTER Ed/Rev Number Clause Number Description of Revision Authorised By Date Ed 1/Rev 0 First issue. Ed 2/Rev 0 Updated to accord with R44 Ed 4 Rev 1. Ed 2/Rev 1 Global References to “Roads and Maritime Services” or “RMS” changed to “Transport for NSW” or “TfNSW” respectively. DCS 22.06.20
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Edition 2 / Revision 1 TRANSPORT FOR NSW
June 2020
TRANSPORT FOR NSW (TfNSW)
SPECIFICATION GUIDE NR44
GUIDE TO QA SPECIFICATION R44
EARTHWORKS
REVISION REGISTER
Ed/Rev
Number
Clause
Number Description of Revision
Authorised
By Date
Ed 1/Rev 0 First issue.
Ed 2/Rev 0 Updated to accord with R44 Ed 4 Rev 1.
Ed 2/Rev 1 Global References to “Roads and Maritime
2 EARTHWORKS MATERIALS .......................................................................................................... 13 2.1 General ......................................................................................................................... 13 2.2 Materials Management ................................................................................................. 13 2.3 Topsoil .......................................................................................................................... 13 2.4 Unsuitable Material ...................................................................................................... 15 2.5 Spoil .............................................................................................................................. 17 2.6 Stockpile Sites .............................................................................................................. 18 2.7 Borrow Sites ................................................................................................................. 19 2.8 Material in Upper Zone of Formation and Verges ....................................................... 20
3 FOUNDATIONS .............................................................................................................................. 22 3.1 General ......................................................................................................................... 22 3.2 Foundations for Embankments ..................................................................................... 22 3.3 Foundation Treatment for Hillside Embankments ....................................................... 27 3.4 Foundation Treatments for Cuttings ............................................................................. 28 3.5 Shallow Embankment and Cut/Fill Transition ............................................................. 34
4 CUTTINGS ..................................................................................................................................... 37 4.1 General ......................................................................................................................... 37 4.2 Excavation .................................................................................................................... 37 4.3 Cuttings in Rock ........................................................................................................... 38 4.4 Batter Tolerances .......................................................................................................... 38 4.5 Benching in Cuttings .................................................................................................... 39 4.6 Pre-splitting or Line Drilling ........................................................................................ 40 4.7 Blasting ......................................................................................................................... 40
5 EMBANKMENTS ............................................................................................................................ 42 5.1 General ......................................................................................................................... 42 5.2 Earth Fill Embankments ............................................................................................... 43 5.3 Rock Fill Embankments ............................................................................................... 46 5.4 Embankment Batters .................................................................................................... 48 5.5 Rock Facing of Embankments ...................................................................................... 49 5.6 Fill Placed Adjacent to Structures ................................................................................ 50
6 STRUCTURAL TREATMENTS ......................................................................................................... 51 6.1 Upper Zone of Formation ............................................................................................. 51 6.2 Verges ........................................................................................................................... 53 6.3 Other Treatments .......................................................................................................... 54
7 ADDITIONAL CONFORMITY REQUIREMENTS ............................................................................... 54 7.1 General ......................................................................................................................... 54 7.2 Earth Fill ....................................................................................................................... 54
NR44 Guide to R44 Earthworks
ii Ed 2 / Rev 1
7.3 Rock Fill ...................................................................................................................... 57 7.4 Deflection Testing........................................................................................................ 58 7.5 Level Control ............................................................................................................... 60
ANNEXURE R44/A – PROJECT SPECIFIC INFORMATION ........................................................................ 62 A1 Surveys (Clause 1.6) .................................................................................................... 62 A2 Materials ...................................................................................................................... 63 A3 Foundation Treatment .................................................................................................. 65 A4 Shallow Embankment, Cut/Fill Transition, Upper Zone of Formation and Verges .... 66 A5 Compaction Moisture Requirements (Clause 7.2) ....................................................... 67 A6 Blasting (Clause 4.7).................................................................................................... 68
ANNEXURE R44/B – MEASUREMENT AND PAYMENT ........................................................................... 70
ANNEXURE R44/C – SCHEDULES OF HOLD POINTS, WITNESS POINTS AND IDENTIFIED RECORDS ...... 77 C1 Schedule of Hold Points .............................................................................................. 77 C2 Schedule of Witness Points .......................................................................................... 77 C3 Schedule of Identified Records .................................................................................... 78
ANNEXURES R44/D TO R44/K – (NOT USED) ....................................................................................... 78
ANNEXURE R44/L – TEST METHODS, MINIMUM FREQUENCY OF TESTING AND ACCEPTANCE
Payment for the drainage layer will be made in accordance with Pay Item R44P7.4. Material
excavated will be measured and paid in accordance with Pay Item R44P2 or R44P4. The geotextile
will be paid for in accordance with Pay Item R44P7.
3.4.6 Other Treatments
Other foundation treatments may be adopted as shown on the Drawings or as directed or agreed by the
Principal.
3.5 SHALLOW EMBANKMENT AND CUT/FILL TRANSITION
3.5.1 Shallow Embankment
Where the height of the embankment is less than that stated in Annexure R44/A4 for a Shallow
Embankment, excavate the area further to a depth necessary to achieve the minimum height, unless
otherwise shown on the Drawings or directed by the Principal.
You may propose to the Principal a height that is less than the minimum height stated for a Shallow
Embankment to reduce the depth of excavation required. Carry out CBR and PI tests on the
embankment foundation at this proposed higher level and submit them to the Principal. For this lesser
height to be approved by the Principal, the CBR and PI values must comply with those stated in
Annexure R44/A2.2.
This is to confirm design assumptions for the subsequent formation and pavement to be constructed.
Observe the Hold Point in Clause 3.2 and carry out embankment foundation treatments in accordance
with Clause 3.2, before placing the overlying formation.
The thickness of the Upper Zone of Formation will be that corresponding to “shallow embankment” in
Annexure R44/A4, and will generally be the entire formation from Foundation Level to Top of
Formation, unless shown otherwise in Annexure R44/A4. Fill placed within this zone must comply
with that for Upper Zone of Formation material.
MEDIAN (dual carriageways only)
Designed Finished Surface Level
Selected Material Zone
BATTER
Top of Formation Pavement
Refer to Drawings
for drainage details
Verge or Pavement (see Drawings)
Unsuitable Material
(replaced as directed)
Upper Zone of Formation
Foundation Level
Selected Material Zone may extend to edge - see Drawings
Drainage Layer
Geotextile
Designed Floor Level *
* unless shown otherwise on the Drawings
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
Guide to R44 Earthworks NR44
Ed 2 / Rev 1 35
Notes:
(1) Where the height from Stripped Surface Level to Top of Formation is less than minimum height for Shallow Embankment
(refer to Annexure R44/A4), further excavation to achieve the minimum height for Shallow Embankment is required.
(2) The thickness of the Upper Zone of Formation will be that corresponding to “shallow embankment” in Annexure R44/A4,
and will generally be the entire formation from Foundation Level to Top of Formation, unless shown otherwise in
Annexure R44/A4.
Figure R44.6(a) – Shallow Embankment Nomenclature
The volume of material excavated is to be included in the measured volume for General Earthworks.
This effectively changes the shallow embankment into a cutting. The requirement is intended to deal
with the major problems that occur with poor drainage and unsuitable materials in this situation, in
the same way as the cut/fill transition treatment. It effectively converts the necessary excavation into
the foundations from unsuitable to general earthworks and makes it necessary to take the resultant
quantities into account in the earthworks balance. The temptation to minimise the nominated depth
should be resisted. It may reduce the physical work required, but could mean that it is paid for at a
higher rate and ordered up piecemeal (thus minimising the chances of it being programmed properly).
As a general guide, embankments should be designed for a minimum height of 1.5 m (2 m is
preferable) from the foundation level to the top of the Selected Material Zone to allow for bridging
and minimise the potential need for excavation below the natural surface.
Shallow embankments commonly arise under the following circumstances:
Adjacent to cut/fill transitions (the requirement applies to the full width of the embankment, not
just the area underneath the pavement
Local topographic highs which do not reach the grade line
Urban situations where embankment levels are dictated by the need to match adjoining properties
Extensive low fills on flat, low-lying or gently sloping ground, where the natural slope follows the
gradient of the control line.
Shallow embankments are inevitable under the first three circumstances, but should be avoided, as far
as possible, in the fourth.
3.5.2 Cut/Fill Transition
Following excavation to the Designed Floor Level at the cut/fill transition, within the area classed as
Shallow Embankment in accordance with Clause 3.5.1, carry out further excavation, parallel to the
cutting floor, below the Designed Floor Level, to a depth necessary to achieve the minimum height
specified in Annexure R44/A4 for a Shallow Embankment, as shown in Figure R44.6(b).
Care needs to be taken to ensure that depths of excavation for the cut/fill transition and shallow
embankment are compatible. It is also important to consider the stability of the vertical faces of the
excavation, particularly if the vertical face is at the base of a planned cutting slope. The cutting
stability will likely be reduced by the excavation and backfilling should be carried out as soon as
practicable to eliminate this risk
Stripped Surface Level (after removal
of topsoil)
Selected Material Zone
Pavement
Designed Finished Surface Level
MEDIAN (dual carriageways only) BATTER
Top of Formation
Verge or Pavement (see Drawings) Selected Material Zone
may extend to edge
- see Drawings
Foundation Level after excavation to minimum depth
for Shallow Embankment (1)
Upper Zone of
Formation (2)
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
NR44 Guide to R44 Earthworks
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This additional excavation must extend into the cut for a distance of 10 m from the line resulting from
the intersection of the plane of the Designed Floor Level with the plane of the stripped surface, as
shown in Figure R44.6(b). The 10 m is measured perpendicular to the line of intersection between the
two planes.
This cut/fill transition treatment must not however extend into the cutting batter.
Plan View Notes:
(1) Where the height from the Stripped Surface Level to the Top of Formation is greater than the minimum height for a
Shallow Embankment, no further excavation below the Stripped Surface Level, other than terracing, is necessary. The
thickness of the Upper Zone of Formation will be that corresponding to “embankment” in Annexure R44/A4. The fill
below the Upper Zone of Formation may be General Fill.
(2) Where the height from the Stripped Surface Level to the Top of Formation is less than the minimum height for a Shallow
Embankment, further excavation to achieve the minimum height for Shallow Embankment is necessary. This excavation
extends into the cut for a further 10 m as part of the Cut/Fill Transition Zone.
The thickness of the Upper Zone of Formation will be that corresponding to “cut/fill transition” in Annexure R44/A4.
(3) Beyond the Cut/Fill Transition Zone, the thickness of the Upper Zone of Formation will be that corresponding to
“cutting” in Annexure R44/A4.
(4) The 10 m is measured perpendicular to the line resulting from the intersection of the plane of the Designed Floor Level
with the plane of the stripped surface.
Figure R44.6(b) – Cut/Fill Transition Treatment
Within this transition zone, the requirements of Clause 3.5.1 for Shallow Embankment apply.
The volume of material excavated is to be included in the measured volume for General Earthworks.
Ensure that the excavation is free-draining by either sloping toward the nearest exit of the cutting at a
minimum grade of 1%, or installing a subsurface drain at the lower end of the excavation unless
otherwise shown on the Drawings or directed by the Principal. Installation, and payment, of the
subsurface drains must be in accordance with Specification TfNSW R33.
The purpose of the excavation of the cut/fill line is to remove potentially poor quality near surface
material from the upper zone of formation. Note that the requirement applies equally to side cuts.
Upper Zone
of Formation (2)
Foundation Level
after excavation to minimum
height for Shallow Embankment
Top of Formation
Terracing
as required
Designed Floor Level
(base of Selected Material Zone)
Stripped Surface Level
(after removal of topsoil)
Selected Material Zone
10 m (4)
Intersection
line
Transition Zone
Extent of additional excavation
Upper Zone
of Formation (1)
General Fill
Upper Zone of Formation (2)
Upper Zone of Formation (3)
“Shallow
Embankment”
10 m (4)
Cutting batter after excavation
to Designed Floor Level
Intersection
line
Extent of additional
excavation into cut
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
Guide to R44 Earthworks NR44
Ed 2 / Rev 1 37
The thickness of the zone should be chosen and specified in the Annexure to suit each individual
project and its materials.
We need to be aware of very flat existing side slopes which can result in very long skewed transitions
resulting in significant increases in earthworks volumes. It is worthwhile to prepare plan drawings
which show the intersection line after topsoil stripping, together with an additional contour at the
cut/fill transition depth.
The location of the back of the excavation (10 m on the cut side of the intersection line, measured
normal to that line) can also be shown. This will help avoid the problem described above and will
provide a good basis for deriving quantities. It makes the scale of the task explicit to tenderers and
provides tenderers with a breakdown of cut/fill line quantities throughout the job for inclusion in the
earthworks plan).
Material removed from beyond the 10 m line is treated as unsuitable.
4 CUTTINGS
4.1 GENERAL
Construction of cuttings includes all operations associated with the excavation of material within the
limits of the batters including benching, terracing of cut batters, cleaning of batter surfaces, treatment
of cutting floors, foundation treatments in accordance with Clause 3.4, beneath Shallow Embankments
in accordance with Clause 3.5.1, and cut/fill transition in accordance with Clause 3.5.2.
4.2 EXCAVATION
Loosen and process the excavated materials as required to meet the Specification requirements for
incorporation in the Works, in particular Clauses 2, 5.6 and 6 of this Specification.
Good site investigations and interpretation of results will assist greatly in this area. Whilst designers
provide changes of slope at changes in expected materials, it is rare that the actual material changes
will be as uniform and clear as the design may imply. For that reason, where changes to slope are
required by the design, good design will where possible also include a bench at that transition from
soft to hard material.
It is important that the cuttings are inspected regularly as they are excavated to confirm the design
parameters and to enable minor adjustments to bench levels and slopes as required. Upper slopes
should be trimmed (and re-vegetated if required) before lower slopes are excavated as it will become
more difficult and more expensive to repair slopes and make changes when the cutting has been more
fully excavated and large plant and equipment cannot access the upper levels with ease.
Benches will also occur for other reasons than a change of material and will not always coincide with
rock quality transitions. The need to allow for access to the upper parts of a slope for maintenance
should be considered in the design. Persons supervising cut batter construction should be familiar
with the design philosophy of the cut and its implications, to avoid making decisions “on site” which
conflict with design objectives.
The batter slopes in cuttings must be in accordance with those shown on the Drawings, or as
re-determined by the Principal, following a site inspection and investigation during excavation.
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
NR44 Guide to R44 Earthworks
38 Ed 2 / Rev 1
Round off the tops of cuttings to the dimensions shown on the Drawings unless otherwise directed.
Batters will generally require progressive flattening at the ends of cuttings owing to the presence of
less stable material. In all cuttings, undulations in the general plane of the batter are not acceptable.
The cutting must be free of rills running down the face of the batter (except for pre-splitting holes).
Treat the face of the batter if such treatment is shown on the Drawings.
Clear the cut faces of any loose or unstable material progressively as the excavation proceeds.
4.3 CUTTINGS IN ROCK
Clean the cut batters in rock with slopes of 1H:1V or steeper, using compressed air, to allow
inspection of the batter and assessment of its stability immediately following completion of excavation
to the level of each bench. Do not use water jets and air-water jets unless specifically approved by the
Principal for specific areas. Remove any loose or unstable blocks which are too large to be removed
by the above means, by hand or machine, unless otherwise directed by the Principal.
Clean also the surface of the bench at the top of the batter by compressed air, unless otherwise directed
by the Principal.
Continue cleaning until all loose rock and soil material is removed, and all rock and joint surfaces are
sufficiently exposed so that the Principal can assess their condition and likely effect on the stability of
the batter.
HOLD POINT
Process Held: Excavation below bench level for slopes of 1H:1V or steeper.
Submission Details: Presentation of cleaned batter and bench/floor surfaces for geotechnical
inspection.
Release of Hold Point: The Principal will inspect the cleaned surfaces and may direct further action
prior to authorising the release of the Hold Point. Further action may include
additional cleaning (if the condition of the faces cannot, in the opinion of the
Principal, be adequately assessed), and stabilisation works, prior to or
concurrent with any further work within the cutting.
Following inspection, the Principal may direct additional stabilisation works, including changes to the
batter slope.
The scope of stabilisation works should be determined, as far as possible, prior to tender and suitable
treatment quantities allowed. In some cases, special provisions may be needed in R44.
4.4 BATTER TOLERANCES
Excavation of batters must comply with the tolerances given in Table R44.3.
Table R44.3 – Excavation Tolerances for Batters in Cuttings
Location Tolerance (mm)
Slope 1H:1V or flatter Steeper than 1H:1V
Batters at toe of batter +0 / –150 +0 / –200
2 m above toe of batter and higher +300 / –300 +300 / –600
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
Guide to R44 Earthworks NR44
Ed 2 / Rev 1 39
Between level of toe of batter and
2 m above toe of batter pro rata basis pro rata basis
Note: Plus (+) is towards the roadway and minus (–) is away from the roadway. Tolerances are
measured perpendicular to the plane of the slope.
If the batter is over-excavated beyond the tolerance applicable for the batter slope line, or after
cleaning the batter is beyond the tolerance applicable, restore the batter to the specified slope and
stability to the Principal's satisfaction. Proposals for restoration must take into account long term
stability, durability, and consideration of urban design solutions. The cost of restoring or re-forming
the batter must be borne by you.
Restoration of earth batters would normally be carried out using conventional small plant,
remembering to terrace the natural material before compacting fresh material in layers. In rock
cuttings, restoration could be by coloured concrete or by hand placed mortared stone pitching. Urban
design issues and the likelihood of impacting by errant vehicles will influence this decision.
Restoration of rock cuttings could also involve rock bolting of potentially unstable material.
The appropriateness of the standard tolerances should be considered against the expected condition of
the rock mass after excavation. Alternative requirements may be specified if conditions warrant them.
Such requirements could include pre-splitting, closely-spaced line drilling and/or the use of specialist
mining equipment. Economics and urban design aesthetic values will govern the decisions against the
alternative solutions of rock-bolting and shotcreting. Safety considerations for the severity of vehicle
impacts govern the finish requirements for the lower 2 m of the batter.
For batters steeper than 1H:1V, if any section of the batter up to a height of 3 m above the toe of batter
has been over excavated beyond the tolerance limit specified, the Principal may direct that the batter
be re-formed to the average batter slope using randomly mortared stone or other treatments. Where
stone is directed, it must be similar to the sound rock in the cutting and the mortar must be coloured to
match the colour of the rock.
Alternatively, you may request a minor change in the general slope of the batter for your convenience.
If the Principal approves such a change, it will not be regarded as a redetermination of the batter slope
under Clause 4.2 and no additional payment will be made. If your request is denied, restore the batter
to the specified slope and stability to the satisfaction of Principal.
4.5 BENCHING IN CUTTINGS
Cut batters must be benched as shown on the Drawings to provide drainage and erosion control, to
provide geotechnical stability, and to allow access for maintenance purposes. Notwithstanding the
tolerances permitted under Clause 4.4, bench widths must not be less than those shown on the
Drawings.
The floor of the bench must not vary from levels shown on the Drawings by more than the tolerances
shown in Clause 7.5, but the bench must have a crossfall to drain water away from the cut face
immediately below the bench. Provide and maintain longitudinal drainage to prevent ponding of water
on the benches.
Construct bench drains, where shown on the Drawings, progressively as each batter face is completed.
Payment for this work will be made in accordance with TfNSW R33.
Maintain and regularly clean the benches of any loose materials throughout the Contract period. The
cost of such maintenance and cleaning of benches is deemed to be included in the rates generally.
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
NR44 Guide to R44 Earthworks
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4.6 PRE-SPLITTING OR LINE DRILLING
Use pre-splitting or line drilling to produce a uniform and neat batter surface after excavation or to
ensure protection of batters prior to burden blasts.
Extensive blasting is not usually required in cuttings with a 1:1 or flatter slope, as the material will
usually be able to be ripped. There are however many exceptions, particularly in igneous rocks such
as granite which weather variably. Batter design may be governed by the more weathered rock (or its
ultimate condition if it is expected to degrade with time) and excavation by the less weathered. We
need to be very careful not to imply that excavation characteristics can be predicted from batter
slopes.
Pre-splitting and line drilling are very difficult to do on such slopes due to the difficulty in controlling
the direction of drilling when angled so far from the vertical plane. Where blasting is required in
these conditions (usually because of variable rock strength), most contractors will propose an
alternative of normal drill and blast and cleaning up/trimming of the batter using rock hammers to
achieve the specified tolerances.
Where flat batters e.g. 2:1 are specified, consideration needs to be given to modifying the specified
tolerances.
The Principal will give consideration to an alternative method of excavation and preparation of the cut
face so as to produce a result equivalent to that produced from pre-splitting or line drilling. Approval
to such alternative methods will be granted at the absolute discretion of the Principal, who may require
a trial section of the proposed method to be carried out to demonstrate its suitability.
Where pre-splitting or line drilling is carried out, the centre-to-centre spacing of drill holes must not
exceed the values in Table R44.4.
Table R44.4 – Hole Diameter and Spacing for Pre-splitting or Line Drilling
Cut Batter Treatment Hole Diameter (mm) Maximum Hole Spacing (mm)
Pre-splitting 38 – 51 450
Pre-splitting 51 – 64 750
Pre-splitting 76 – 89 900
Line Drilling Up to 51 150
Line Drilling 51 – 76 250
4.7 BLASTING
4.7.1 General
The following applies only where blasting is permitted under the Contract, as indicated in Annexure
R44/A6.
Obtain all necessary licences from the appropriate authorities and comply with all Government
regulations relating to transport, storage, handling and the use of explosives and also the rules set out
in AS 2187 Parts 1 and 2. Comply with the requirements of all external agencies including, but not
limited to, the Environment Protection Authority (EPA) and the WorkCover Authority and
demonstrate compliance.
Do not use exposed detonating cord in built-up areas. Demonstrate compliance with Clause 6.8 of
Specification TfNSW G35 or G36, as applicable.
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
Guide to R44 Earthworks NR44
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The Vibration and Air Blast Management Plan (refer to Specification TfNSW G35 or G36, as
applicable) must contain details of review and verification of the above requirements and its
operations to ensure that the public, building structures and infrastructure are protected.
HOLD POINT
Process Held: Start of each blasting operation.
Submission Details: Written details of the proposed blasting procedure including the quantity and
type of explosive to be detonated, the blasting pattern to be used and
measures proposed to limit noise and to ensure that vibration from blasting
does not adversely affect nearby structures. This must be contained in the
Vibration and Air Blast Management Plan.
Release of Hold Point: The Principal will consider the submitted documents, prior to authorising the
release of the Hold Point.
Provide certification of the adequacy of the Building Condition Inspection to the Principal at least
three days before the blasting is due to commence. Monitor and report the Building Condition during
the blasting operations. You are responsible for all costs associated with the inspections and reports if
no Pay Item has been provided in Specification TfNSW G36 for this work.
Monitor all blasts for ground vibration and air blast to ensure that the ground vibration and air blast
level caused by blasting does not exceed the respective values of peak particle velocity and air blast
overpressure listed in Annexure R44/A6 and the requirements of Specification TfNSW G35 or G36, as
applicable.
Implement and maintain a community liaison program during blasting activities to keep people in the
vicinity of the Works informed of any activities. Address levels of vibration or air blast.
Advise all residents within a radius of 1 km from the site of the proposed blasting, before blasting
operations commence. Written advice must include the likely times, frequency and duration of
blasting and precautions being taken to ensure that damage to property will not result.
Confine your blasting operations to the weekdays of Mondays to Fridays but excluding public
holidays, between the hours of 9 am and 3 pm, unless otherwise approved by the Principal.
Do not detonate a blast prior to the time that has been announced for that blast, unless otherwise
approved by the Principal.
When blasting operations are being carried out, take precautions relating to the safety of persons and
animals. Close any roads likely to be affected by the blasting to traffic and erect the appropriate signs
in accordance with Specification TfNSW G10. Establish a standard warning procedure such as that
given in the NAASRA Explosives in Roadworks Users Guide 1982 and observe the procedure at all
times.
Clearly outline in the Vibration and Air Blast Management Plan a detailed procedure to be followed in
the event of a misfire.
4.7.2 Pre-splitting or Line Drilling Prior to Blasting
Prior to commencing blasting, batters with gradients 1H:1V or steeper must be pre-split or line drilled
in accordance with Clause 4.6 to the design batter profile at sufficiently close centres to produce a
uniform and neat batter surface after excavation acceptable to the Principal.
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
NR44 Guide to R44 Earthworks
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4.7.3 Blasting Records
Maintain accurate records of each blast including the details listed below:
(a) Date, identification number and time of blast;
(b) Location, number and diameter of blast holes loaded;
(c) Depth of each drill hole loaded;
(d) Inclination of drill holes;
(e) Burden(s) and spacing(s);
(f) Types and amounts of explosives used;
(g) Maximum instantaneous charge;
(h) Initiation Plan;
(i) Length and type of stemming in each blast hole;
(j) Ground vibration and noise levels at measuring locations.
The records must be written as the holes are loaded, and must be signed by the shotfirer. Provide a
copy of the records to the Principal on the day of the blast.
Blasting is a hazardous operation and may be an issue with nearby residents. Contractors usually
sub-contract this work to blasting specialists and it needs to be stressed to all involved that the main
contractor must take interest in the details of the blasts so as to minimise damage to properties and
adverse community reactions.
We must ensure that full details of each blast are properly recorded as specified above, as a minimum.
The above items (a) to (i) should be recorded and available for inspection before the blast is carried
out. If difficulties occur with vibration or airblast damage, we will usually require a thorough review
of the blast procedure, specifically dealing with the maximum instantaneous charge, the types and
number of delays and the type of stemming in the holes. We must therefore be able to examine full
details of all blasts and satisfy ourselves that appropriate steps are being taken.
This is a difficult situation as subsequent blasts need to be very conservative in order to ensure no
further damage. Insistence of review of the blasting proposal by an independent experienced and
qualified person is suggested. Re-commencement of blasting should be on a trial basis, be very
conservative and be closely monitored by measuring equipment as well as in person by TfNSW
engineers and inspectors.
5 EMBANKMENTS
5.1 GENERAL
Embankment construction includes:
(a) the preparation of the foundation areas over which fill material is to be placed as described in
Clause 3 and backfilling of excavations undertaken for foundation treatments for both cuttings
and embankments;
(b) the placement and compaction of conforming material within areas from which unsuitable
material has been removed in accordance with Clause 2.4 and within areas where material has
been removed below the pavement zone in cuttings and cut/fill transitions;
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Guide to R44 Earthworks NR44
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(c) the placement and compaction of fill material and of materials of specified quality in nominated
zones throughout the Works, including “spill-through” bridge abutments zones where
subsequent pile foundation works are to be undertaken;
(d) all other activities required to produce embankments as specified, to the alignment, grading and
dimensions shown on the Drawings.
Earth fill embankments are embankments not conforming to rock fill requirements (refer Clause 5.3).
Material for embankment construction must be obtained from excavations within the Works and,
where authorised by the Principal, may be supplemented with borrowed or imported material in
accordance with Clauses 2.7 and 2.8. The material must be free of tree stumps, roots and refuse.
Embankment construction (other than for foundation treatments as specified in Clause 3, Upper Zone
of Formation and verges) must be in accordance with the requirements of either Clause 5.2 or 5.3, as
applicable.
Process those materials which do not meet the requirements of these Clauses to ensure conformity
prior to placement. Select the methods of excavation, transport, depositing and spreading of the fill
material so as to ensure that the placed material in any Lot is homogeneous.
Place fill material for embankment construction in layers parallel to the grade line.
Achieve relative compaction specified in Clause 7 over the full depth of the layer. Describe in the
EARTHWORKS PLAN the method used to verify that the specified compaction has been achieved
over the full layer depth and that the layer depth has not been exceeded.
Compaction must also be achieved over the full width of the formation. At times, this may mean
construction of over-wide embankments and subsequent trimming of loose material from the edges.
Programme and manage the Works as detailed in EARTHWORKS PLAN (Clauses 1.5 and 2.2) so
that material of the quality specified in Clause 2.8 for the Upper Zone of Formation and verges is
available when required.
Generally, material for selected material zone and verge material will need to be stockpiled (and often
processed by crushing or screening) before placement in an embankment.
Embankment material zones are as illustrated in Figure R44.2.
5.2 EARTH FILL EMBANKMENTS
Construct the embankment so as to derive its stability from compaction of the fine material around the
coarser particles. Rock material must be broken down and evenly distributed throughout the layer to
prevent the formation of voids and to produce a dense compact embankment. To meet this
requirement, additional fine material may need to be obtained from other places within the Works or
by a change in the method of winning and processing the material.
Maximum layer thicknesses and particle size limitations are given in Table R44.5.
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Table R44.5 – Maximum Layer Thickness and Material Properties of Rock in Earth Fill
Embankments
Maximum Layer
Thickness (mm)
Minimum Quantity
Rock (by volume)
Maximum Rock
Size
(any dimension, mm)
% Passing 37.5 mm
AS Sieve (by mass)
300 Not specified 200 > 60%
500 25% > 200 mm 300 > 60%
Maximum layer thicknesses are specified to help ensure that the specified compaction can be obtained
throughout the full depth of each layer. The ability to achieve compaction in a layer is limited by the
thickness, material type and condition and the available plant. In general, compaction within a layer
will never be uniform and as the thickness increases will be much lower towards the base of the layer.
The requirement means that even the least compacted parts of the layer must reach the specified
relative density. The Contractor is required to have an acceptable method which will demonstrate
that this has been achieved.
In order to demonstrate compaction over the full layer thickness that thickness must be known.
Therefore a method of demonstrating layer thickness must be available. Possible methods include
direct measurement (by extending sampling holes for T111/T112 to the base of he layer), survey or
differential GPS measurements from compaction plant or graders.
Density testing by T173 cannot demonstrate full depth compaction of 500 mm layers as the test is
limited to 300 mm by the maximum extension of the probe of the nuclear gauge. Such a layer will
also, by definition, contain too much oversized rock to allow use of the method T119 (the sand
replacement method) can by used with thicker layers.
Demonstrating conforming average density over the layer depth is not sufficient to meet the specified
requirement, due to the depth effects described above. This is not normally an issue with layers
conforming to thickness requirements but is a major concern where 500 mm layers are being used or
the 300 mm limit is not being observed. Geotechnical advice should be sought if here is a need to
investigate this issue.
The conformance requirements (Clause 7) are intended to ensure that the smaller particles and fines
between cobbles and boulders in the layer are properly compacted. Obviously, density testing of
boulders themselves is not relevant to compaction testing. The 60% by mass passing a 37.5mm sieve,
quoted in the table above, is assessed from the samples recovered for compaction testing. It should be
understood that the requirement refers to the material forming the layer, not the individual samples.
Sampling effects mean that if the oversize content for the layer as a whole is near the specified limit,
some samples will exceed that limit.
The maximum size of rock is specified in any direction. This is to ensure that each rock particle is
wholly contained within the layer being placed and compacted. Rocks which break into large flat
plates are undesirable as they will tend to leave gaps underneath the edges and be unstable in a thin
layer.
Where more than 20% by mass of fill material is retained on the 37.5 mm AS sieve, or the compacted
layer thickness exceeds 300 mm, do not use nuclear density gauges for insitu density tests.
The T173 test (nuclear density gauge test) measures the average density of the material between two
points (the source at the end of the probe, at or near the bottom of the layer, and the detector at the
top of the layer, with a horizontal offset of about 300 mm between them), including any boulders that
may be present. The 20% limit applies because the relationship used to calculate the field density
within the nuclear gauge breaks down if there is too much large rock of much greater density than the
finer matrix.
Sand replacement densities (T119) can be conducted up to a rock content of 40%, which is the overall
limit in the specification for rock content of an earth fill. The reference density (T162 or T111)
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excludes the larger rock (> 37.5 mm) simply because the test can’t be done if it is included. There is a
correction applied for the proportion of larger rock and its density, to allow comparison with the field
density.
The layer thickness (after compaction) must not be less than 100 mm.
The maximum size of rock pieces should not exceed 2/3 the layer thickness. For a thin 100mm layer,
the maximum particle size would be approximately 60mm.
In placing embankment layers, use equipment and techniques to avoid surface heaving or other
damage to the foundations and underlying embankment layers.
If heavy haulage equipment is required to pass over the completed work, the paths of the haulage
vehicles need to be varied to avoid failures caused by repeated loading in the same location.
5.2.1 Earth Fill at “Spill-Through” Bridge Abutments
For the earth fill at “spill-through” bridge abutments, the geometry is as shown in Figure R44.7.
At one end, it forms the exposed sloping part of the “spill-through” embankment. At the other end, at
the top, it extends a distance of 2h from the rear face of the bridge abutment headstock; at the bottom
at embankment foundation level, it extends a distance of h/2 from this rear face.
(For the purpose of this Clause, the height “h” is the distance between the soffit of the headstock and
the embankment foundation level. Where excavation is required for foundation improvement, the
height “h” is measured to the base of the excavation.)
Figure R44.7 – Dimensions of Fill at “Spill-Through” Bridge Abutments
The fill material must comply with the requirements of Clause 2.8.5.
Prior to placement, the material must be stockpiled, sampled and tested for conformity in accordance
with the requirements of Clause 6.1.2.
Each layer must not exceed 300 mm in thickness when compacted and must be compacted to the
requirements stated in Table R44.11.
h
h/
2
2h
Soffit of Headstock
Embankment
Foundation Level
h/2
Note: Dashed line above indicates location of
batter behind abutment, and extent of earth fill
complying with Clause 5.2.1, if abutment fill is
placed prior to adjoining embankment.
Earth fill
complying with
Clause 5.2.1
UZF other than SMZ
Selected Material Zone
Slope terraced
in accordance
with Clause 3.3
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Rocks must not be dumped against the columns or retaining walls but must be built up evenly by hand
placing around or against such structures.
Scour protection of the embankment is not considered in this Clause and, where necessary, must be
considered separately.
5.3 ROCK FILL EMBANKMENTS
5.3.1 Introduction
For the purpose of this Clause, a rock fill embankment is an embankment constructed of hard, sound
rock, containing only a small amount of fine particles, which derives its stability from the mechanical
interlock of the coarser particles, rather than from the compaction of the finer material.
Except where shown on the Drawings, do not place rock fill in areas where earth fill has previously
been constructed. If you elect to construct a rock fill embankment, adjust the working methods
employed in the excavation of cuttings so as to produce rock fill material of the grading and rock
strength specified in Clause 5.3.2. Such working methods must include screening and, if necessary,
secondary processing.
Place and spread the rock fill material in such a way as to avoid segregation and to ensure that it is not
contaminated with foreign material. The compacted rock fill layer thickness must not exceed 550 mm.
Compact the rock fill using the nominated compaction routine, developed as specified in Clause 7.3.
Material that does not meet the requirements for rock fill specified in this Clause must be broken down
further into finer particles, or have additional fines incorporated, and used in earth fill embankments in
accordance with Clause 5.2.
Nominate to the Principal the proposed areas of rock fill. If you elect to construct earth fill in part or
all of the nominated rock fill locations, and a surplus of rock, capable of being processed for rock fill,
is later found to exist, then treat the surplus by:
(a) processing the material for use as earth fill; or
(b) removal of earth fill and placement of the surplus rock as rock fill at your cost.
Shape and treat the foundations under rock fills to maintain drainage and to ensure that erosion of the
foundation will not occur.
Protection from future erosion of the foundation area below the rock fill should be carried out by
construction of suitable diversion drains and the placement of geo-textile material at the foundation
level of the rock fill.
Special measures may also be needed to protect culvert backfill material from erosion by water
flowing through a rockfill when the culvert is operating under afflux. This may involve the use of a
non-erodable and free draining select bedding and backfill material around the pipe, such as a 14mm
or 20mm crushed aggregate.
5.3.2 Rock Fill Material
Rock fill material must comply with Table R44.6. The constituent particles must be of uniform
strength and soundness.
The values specified in the Annexure should be chosen following discussions with experienced
geotechnical experts and extensive site investigation and testing of expected materials. The limit
should be specified to make distinction between acceptable and unacceptable materials as easy as
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possible. This will require good knowledge of the expected strength characteristics of the rock and
their distribution. It is not desirable to set the limit so as to require extensive testing of “marginal”
materials to determine their suitability.
The properties in the table below are specified to limit the fines in the fill and to ensure that stability of
the fill is achieved by point contact of rock particles and to ensure that fines do not prevent that point
contact.
Table R44.6 – Rock Fill Material Properties
Property Requirement
Maximum particle dimension 300 mm
Percentage passing:
100 mm AS sieve 0 – 20%
19.0 mm AS sieve 0 – 10%
1.18 mm AS sieve 0 – 5%
Percentage of +100 mm fraction with
Is(50) < Annexure R44/A2.2
10% (max)
Wet/Dry Strength Variation Annexure A2.2
5.3.3 Overlying Layers
Do not place rock fill within 600 mm of the underside of the Selected Material Zone. The minimum
depth to rock fill below the underside of the Selected Material Zone is increased to 1.0 m where safety
barrier, posts, subsurface drainage or services are to be installed.
This requirement is to ensure deflections at the surface are reasonably consistent and that, in service,
the material from the Selected Material Zone does not migrate downwards into the voids of the rock
fill. The remaining requirement is so that large rocks are not near the surface where they would
impede the driving of guardrail posts or the future construction of other trenches.
Place a capping layer of 300 mm (+100 mm / –0 mm) thickness after compaction, composed of graded
rock fill immediately above the completed rock fill embankments. The material in the capping layer
must comply with the properties shown in Table R44.7.
Table R44.7 – Capping Layer Material Properties
Property Requirement
Maximum particle dimension 150 mm
Percentage passing:
19.0 mm AS sieve 0 – 10%
1.18 mm AS sieve 0 – 5%
Percentage of +19.0 mm fraction with
Is(50) < Annexure R44/A2.2 10% (max)
Wet/Dry Strength Variation Annexure A2.2
The grading of the capping layer has been chosen so that it behaves as a “graded filter” to minimise
the material from subsequent layers of fine material migrating down to the voids of the rock fill. In
addition to this capping layer, geo-textile separation layers specified below are also required.
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Place and spread the material for the capping layer in such a way as to avoid segregation and to ensure
that it is not contaminated with foreign material. Compact the capping layer using the nominated
compaction routine, developed as specified in Clause 7.3.
5.3.4 Rock Fill Around Structures
Notwithstanding requirements elsewhere in this Specification, the thickness of backfill around
structures specified in Clause 5.6.3 within rock fill embankments must be at least:
horizontally: 2.0 m (measured normal to the axis of the structure)
vertically: 1.0 m (where rock fill is to be placed over the structure).
The requirement is to avoid damage to structures by impact during construction or point loads in
service.
5.3.5 Geotextiles
Place geotextile separation layers conforming to the requirements of TfNSW R63 as follows:
Class D: beneath the first layer of rock fill.
Class D: between backfill to structures and the adjacent rock fill.
Class C: between the capping layer defined in Clause 5.3.3 and the overlying layer of earth fill.
Payment for geotextiles will be made under Pay Item R44P7.3 for Treatment Type E4.
5.4 EMBANKMENT BATTERS
The batter slopes shown on the Drawings may be subject to re-determination by the Principal
depending upon the materials encountered.
When completed, the batters of embankments must conform to those shown on the Drawings unless
otherwise authorised or re-determined by the Principal.
The tolerances for construction of embankment batters are detailed in Table R44.8.
Table R44.8 – Tolerances for Embankment Batters
Location Tolerance (mm)
Slope 1H:1V or flatter Steeper than 1H:1V
At level of Top of Formation/underside of
pavement +0 / –150 +0 / –150
1 m below Top of Formation and higher +150 / –150 +150 / –150
1 m below Top of Formation and lower +300 / –300 +300 / –300
Note: Plus (+) is towards the roadway and minus (–) is away from the roadway. Tolerances are measured
perpendicular to the plane of the slope.
Near the surface of the completed pavement, the shape of the batter is particularly important to ensure
safety for motorists in an out of control run-off.
Notwithstanding the above, the edge of the formation at the level of the underside of the pavement
must not be nearer to the roadway than that shown on the Drawings.
This is required so that the pavement can be constructed to its full width as designed.
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Undulations in the general plane of the batter are not acceptable. The completed batter must be free of
rills running down the face of the batter.
Rills should be repaired as soon as practicable, as they are areas where water flow concentrates and
they generally develop into larger gullies through repeated scouring, eventually compromising the
stability of the formation. This matter is closely related to the batter slope angle and the face length
provided. Excessive face lengths or over-steep slopes will make rill formation inevitable in most
earthfill materials. The provision of berms to break up long slopes should be considered. Good
design, together with early revegetation, are essential in order to avoid these problems.
Promptly remove any loose material on the batters as the work progresses.
Placement of additional material on the existing embankment batters must be carried out in the same
manner as that specified for placement of hillside embankments in Clause 3.3.
This is so the new material is keyed in to the original material. Without the key, slope failure will be
more likely.) It also allows the new fill to be compacted against the interface. Consideration needs to
be given to drainage arrangements at the interface when widening on the downslope side of side fills.
5.5 ROCK FACING OF EMBANKMENTS
Where shown on the Drawings, provide a rock facing of clean, hard, durable rock over embankment
batters (including embankments at bridge structures) separated from the earth fill material with a
geotextile complying with TfNSW R63. Place the rock facing outside of the general embankment
dimensions.
Rock facing serves two purposes. It is a way of preventing scour of steep embankments and also an
economical way of dealing with large rock pieces. It is often specified under spill through bridge
abutments where lack of sunlight and water make revegetation difficult. The geotextile is placed
under the rock facing to prevent water running below the rock facing, causing erosion of the
underlying material.
Rock used for rock facing must have a Point Load Strength Index (Is(50)), as determined by Test
Method TfNSW T223, and a Wet/Dry Strength Variation, meeting the respective requirements stated
in Annexure R44/A2.2, and have a minimum dimension of 500 mm.
It is important that the rock is subjected to artificial weathering tests to ensure that it will not break
down prematurely in service. Some shales and siltstones particularly are very hard in situ but
deteriorate rapidly when exposed to cycles of wetting and drying. The test requirements need to be set
appropriately for the materials being considered. This must be job-specific.
You may elect, with the approval of the Principal, to place surplus rock conforming to the above as
rock facing.
The rock facing must be built up in layers ahead of each layer of filling. Place rock in such a manner
that its least dimension is vertical and that mechanical interlock between the larger stones occurs.
Remove any excess of fine material surrounding any rock placed within the rock facing by removing
the rock, removing the excess fine material and re-placing the rock.
Adjust the working methods and program of work to obtain sufficient hard and durable rock of the
specified dimensions to complete the facing as is required. Fill the space between larger batter rocks
and adjacent fill material with progressively smaller rocks to form a graded filter which prevents the
leaching out of fines from the fill material but which does not overfill the voids between larger rocks,
or cause the larger rocks to lose contact with one another.
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Exercise extreme caution whilst placing the rock facing. Where embankment material is placed in the
formation above other roads in use, place the outer rock layer in such a manner as to prevent spillage
down the batter. Implement measures to prevent any rock being dislodged and allowed to roll down
on to any adjacent roadway or track in use.
Payment for the rock facing and drainage layer will be in accordance with Pay Item R44P2. Payment
for the geotextile will be in accordance with Pay Item R44P7.3(a).
5.6 FILL PLACED ADJACENT TO STRUCTURES
5.6.1 General
Supply and placement of fill adjacent to structures is considered to be part of general earthworks. For
the purpose of this Clause, structures include bridges, box and pipe culverts, headwalls and
concrete/masonry retaining walls.
This Clause does not apply to reinforced soil walls (refer to Specifications TfNSW R58 and TfNSW
R59 for their requirements).
Select Fill placed adjacent to culverts and drainage structures, except that adjacent to weep holes, must
be provided in accordance with Specifications TfNSW R11 or TfNSW R22, as applicable. Select Fill
placed against other structures must conform to the requirements of Specification TfNSW B30. Fill
material within the Upper Zone of Formation must also comply with the relevant requirements of
Clause 2.8.
5.6.2 Treatment at Weepholes
Provide drainage adjacent to weepholes using broken stone or river gravel comprising clean, hard,
durable particles, with the following grading:
(i) the maximum particle dimension does not exceed 50 mm; and
(ii) no more than 5% by mass passes the 9.5 mm AS sieve.
The layer of broken stone or river gravel must be continuous in the line of the weep holes, extend at
least 300 mm horizontally into the fill and extend at least 450 mm vertically above the level of the
weepholes.
Alternatively, you may provide a synthetic membrane of equivalent drainage capacity at no extra cost
to the Principal. Store and install it in accordance with manufacturer's instructions. The use of
synthetic membrane as a substitute is subject to the Principal's concurrence.
Many synthetic materials deteriorate when exposed to sunlight. Covering and storing on site should
generally be arranged to avoid exposure to the sun.
5.6.3 Placing Fill Adjacent to Drainage and Bridge Structures
After completion of any backfilling required by Specifications TfNSW B30, TfNSW R11 and TfNSW
R22, place fill complying with Clause 5.6.1 adjacent to structures in accordance with Table R44.9.
Place the fill in accordance with Clauses 3.3 and 5.2 except that layers must have a compacted
thickness between 100 mm and 150 mm. Place layers simultaneously on both sides of box culverts to
avoid differential loading. Compaction must start at the wall and proceed away from it, and must meet
the requirements of Clause 7.
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Cut the existing slope behind the structures listed in Table R44.9 in the form of successive horizontal
terraces, each terrace being at least 1 metre in width, 600 mm in height, and place the fill in
accordance with Clause 5.2.
Do not place fill against structures within twenty-one days after placing concrete in these structures,
unless the concrete strength is verified to have reached the specified 28-day strength.
Where a bridge deck is being concreted adjacent to an abutment, do not place fill against the abutment
within twenty-one days after placing concrete in the bridge deck, unless the concrete strength in the
bridge deck is verified to have reached the specified 28-day strength.
In the case of framed structures, bring up embankments at both ends of the structure simultaneously
and the difference between the levels of the embankments at the respective abutments must not exceed
500 mm unless otherwise shown on the Drawings or within the Specification.
Table R44.9 – Placing of Select Fill
Structure Select Fill
Width Height
Bridge Abutments 2 m H
Box Culverts H/3 H + 300 mm
Retaining Walls H/3 H
(where H = height of structure)
6 STRUCTURAL TREATMENTS
6.1 UPPER ZONE OF FORMATION
6.1.1 General
An Upper Zone of Formation, including a Selected Material Zone (see Figures R44.2(a), R44.2(b),
R44.6(a) and R44.6(b)), must be provided to the thickness specified in Annexure R44/A3 and must
meet the quality requirements specified in Clause 2.8.
Unless otherwise specified, do not place imported material in the Works until all material of suitable
quality available from the cuttings in the Works has been placed or has been assigned to be placed in
the formation.
For economy, projects are usually designed for balanced earthworks with a small excess of spoil or
small amount of borrow material. Imported material if not needed may not only be costly, it may also
result in an unwanted large excess of material towards the end of the job.
Experience suggests that it is prudent to allow for a 7 to 10% surplus in the design and have sufficient
space to spoil any that is not used. There is always wastage for various reasons, accompanied by a
tendency to overbuild embankments, the latter in part to ensure that compaction can be safely
achieved out to the design line.
Where it is apparent that special care will be needed to ensure that the required quantities of
materials for specialised uses can be obtained it may be necessary to impose more restrictive
requirements on working materials management. The TfNSW Contract Manager should then ensure
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that any measures needed, whether specified or not, are reflected in the Earthworks Plan.
Note: This comment applies equally to any issue involving materials management.
HOLD POINT
Process Held: Delivery of imported and site won material for the Upper Zone of
Formation.
Submission Details: Proposed location, quantities and type of material, and verification of
conformity. Verification that all possible sources of the material within the
site have been exhausted.
Release of Hold Point: The Principal will examine details and may inspect the source and stockpiles
of material prior to authorising the release of the Hold Point.
Before placing imported Upper Zone Material in any formation, carry out a survey in accordance with
TfNSW G71 to determine the surface levels at sufficient locations to later determine the volume of
compacted imported material placed in the Works. When shown in Annexure R44/A1, the survey
must be a Joint Survey in accordance with Clause 1.6.
This survey is done to establish the need for imported material and is necessary for payment purposes.
Compaction must be in accordance with Clause 7.
6.1.2 Selected Material Zone
Provide a Selected Material Zone (see Figures R44.2(a), R44.2(b), R44.6(a) and R44.6(b)) where
specified or shown on the Drawings. The Selected Material Zone must be placed and compacted in
layers with the compacted thickness of each layer not exceeding 150 mm unless otherwise specified in
Annexure R44/A4.
The properties specified in the Annexure must be to suit site conditions and must be chosen with
economy in mind. The Selected Material Zone is intended to ensure that the better materials available
from cuttings on the job are used at the surface of the formation, immediately below the pavement.
Sometimes, very hard materials will be available but processing costs may be high. In such cases, a
lesser material which still has an adequate CBR may be preferable due to its lower processing and
handling costs. The limitations on size of particles, layer thickness and compaction requirements are
to provide the best support possible for the pavement with these materials. Often, if good quality
material is not available from within the job, the material is specified to be imported. The choice of
imported material is usually based on economy as whilst this material is of better earthworks quality,
it is usually not as high a quality as pavement material.
Where specified in Annexure R44/A2.1, the material placed in the upper layer of the Selected Material
Zone at any particular location must be from the same source, produced using the same process and
exhibit similar properties prior to any chemical modification which may be required, as that placed in
the lower layer at that same location.
Prior to placement, all material intended for use in the Selected Material Zone must be stockpiled and
tested for conformity with the requirements of Clause 2.8.3 and Annexure R44/A2.2. The total mass
of each Lot of stockpiled material must not exceed 4000 tonnes.
Sampling must be in accordance with Table R44.10 and the characteristic value (Q) of the CBR for
each Lot calculated in accordance with Specification TfNSW Q. For the purpose of this calculation,
report the individual CBR values to the nearest 1% and the characteristic value (Q) to the nearest 0.1%
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Table R44.10 – Sampling Frequency for Selected Material Zone Lots Before Placement
Total Mass of Lot Represented (tonnes) 1 – 500 501 – 1000 1001 – 2000 2001 – 4000
Minimum Number of Samples per Lot 2 3 4 5
HOLD POINT
Process Held: Placement of each Lot of Selected Material Zone.
Submission Details: Submit test reports verifying conformity of each Lot of stockpiled material
for use in Selected Material Zone.
Release of Hold Point: The Principal will consider the submitted documents, prior to authorising the
release of the Hold Point.
After placement, the Selected Material must be homogeneous and free from patches containing
segregated stone or excess fines. The placement methods used must ensure conformity with the
requirements of Clause 2.8.3 and Annexure R44/A2.2.
Trim the Selected Material Zone to meet the tolerances shown in Clause 7.5.1. As part of the
trimming operation, prepare the surface in accordance with Test Method TfNSW T199, for deflection
monitoring as required in Clause 7.4.
HOLD POINT
Process Held: Covering of each Lot of Selected Material Zone.
Submission Details: Verification of conformity of each Lot of Selected Material Zone with
relevant test and survey reports.
Release of Hold Point: The Principal will consider the submitted documents, prior to authorising the
release of the Hold Point.
6.2 VERGES
Provide verges as shown on the Drawings to meet the quality requirements specified in Clause 2.8.
Unless otherwise specified, do not place imported material in the Works until all material of suitable
quality available from the cuttings in the Works has been placed or has been assigned to be placed in
the formation.
HOLD POINT
Process Held: Delivery of imported material for the verges.
Submission Details: Proposed location, quantities and type of material, and verification of
conformity. Verification that all possible sources of the material within the
site have been exhausted.
Release of Hold Point: The Principal will examine details and may inspect the source and stockpiles
of material prior to authorising the release of the Hold Point.
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Carry out a survey in accordance with Specification TfNSW G71:
(a) before placing material in any verge to determine the surface levels at sufficient locations to
later determine the volume of compacted verge material placed in the Works; and
(b) before placing imported material to determine the surface levels at sufficient locations to later
determine the volume of compacted imported material placed in the Works.
When shown in Annexure R44/A1, the surveys must be a Joint Survey in accordance with Clause 1.6.
Place and compact the verge material in layers with the compacted thickness of each layer between
100 mm and 200 mm unless otherwise specified in Annexure R44/A4.
After placement, the material must be homogeneous and free from patches containing segregated stone
or excess fines.
Compaction must be as specified in Clause 7. You may compact adjacent to a concrete pavement only
after at least 10 days after the placement of concrete, or after joint sealing is completed, whichever is
the later.
Damage to freshly placed concrete must be avoided and placement of verge material before sealing of
joints in concrete pavement will result in fine material being deposited in the joints and prevent them
from achieving their designed movement.
Trim the verge to meet the tolerances shown in Clause 7.5.
6.3 OTHER TREATMENTS
Provide other Structural Treatments where shown on the Drawings, to comply with geotechnical or
other design requirements.
7 ADDITIONAL CONFORMITY REQUIREMENTS
7.1 GENERAL
Compact all layers of material placed in the Works uniformly over the full area and depth of the layer
to achieve the relative compaction specified before the next layer is commenced. Trim each layer of
material prior to and during compaction. Complete the compaction promptly to ensure that moisture
content remains conforming and uniform and to minimise the possibility of rain damage.
Unless the treatment of each layer is consistent throughout the layer, the analysis of testing of a layer
using statistical methods becomes irrelevant. This uniformity of treatment is essential to the definition
of a “Lot”.
7.2 EARTH FILL
For all areas and materials listed in Table R44.11, uniformly compact each layer over the full area and
depth of the layer to achieve the relative compaction specified in Clause 7.2.1 before the next layer is
commenced.
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At the time of compaction, maintain the moisture content within the range specified in Annexure
R44/A5 at all locations within the Lot. Adjust the moisture content within that range to enable the
specified compaction to be achieved. Address monitoring and adjusting of moisture content in the
EARTHWORKS PLAN.
Do not compact material that has been placed with a moisture content greater than that specified in
Annexure R44/A5, or has become wetted-up after placement, until it has dried out so that the moisture
content is within the specified range. The drying process may be assisted by aeration or, where
approved by the Principal, by the use of hydrated lime or quick lime, complying with Specification
3211, at your cost.
Alternatively, you may remove the wet material to a stockpile site for drying out and later use as fill
material. Any cost of removal to stockpile, for drying out and later use is deemed to be included in the
rates generally.
The drying out of over-wet material can become very difficult, particularly in very wet seasons and in
winter when drying days and sunlight are short. We ought to be trying to let our contracts in such a
timeframe that these situations are avoided, particularly at the start of a project when large areas for
drying material are simply not available. If we are aware of very wet heavy clays in cuttings and we
know it will be difficult to dry, we should consider specifying and paying for stabilisation to improve
the material properties. Such decisions often result in better pricing by contractors, better site
management as well as an early finish and an overall reduced cost to the project. There may be other
solutions (e.g. spoiling, if the circumstances allow it). The solution should be thought out beforehand
and as far as possible, the work timed to minimise the need for drying or other treatments.
If over optimum material is excavated from cuttings and it is placed deep down in high fills, it may be
possible, with Geotechnical Branch concurrence, to build a stable fill which does not compromise
pavement support or embankment stability. With these materials it is usually easy to achieve
compaction but it is difficult to achieve the specified moisture content. In these cases, there will be
excess pore-water pressures from the compaction and the completed work will tend to “heave” under
heavy plant and machinery.
By waiting a period of time (usually the next day) the pore-water pressures reduce and provided the
material does not heave badly, the next layer can be placed. The best practical method of testing for
heaving is to proof roll in accordance with Clause 7.4.1 with a fully-loaded item of plant and to watch
the surface for movement. There will usually be some movement, however minor movement at depth
will not normally be detrimental to the finished pavement higher up in the fill.).
An alternative location which would usually be suitable for the placement of over optimum moisture
content material is in a wide median area or in very flat, wide batters, sufficiently clear of the
carriageway to not be an influence on the pavement deflections.
Care needs to be taken in placing over-wet material in large embankments. Zoned construction may
be appropriate (placing the wet material in the core of the fill, where large future moisture changes
are unlikely). Placing over-wet clay material full width can lead to stability problems, particularly if
it is highly expansive. Problems with instability under rolling tend to become worse if multiple layers
are placed in quick succession, before compaction-induced pore-pressures can dissipate. Depending
on the nature of the material (including matters such as permeability) it is also possible for apparently
stable layers to become unstable following rain or after wet material is placed on them.
If there is insufficient moisture in the material for it to be compacted as specified, add water. The
added water must be applied uniformly and thoroughly mixed with the material until a homogeneous
mixture is obtained. The cost of such wetting of the material must be borne by you.
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7.2.1 Relative Compaction Conformity Criteria
Carry out compaction control using Standard compaction on Lots using statistical techniques in
accordance with Specification TfNSW Q. Conformity of a Lot will be achieved if the characteristic
value of relative compaction of that Lot is not less than the lower limit specified in Table R44.11.
Table R44.11 – Lower Limit for Characteristic Values of Relative Compaction
Location Lower Limit of Characteristic
Value of Relative Compaction
Earth mounds
Spoil 90.0%
Foundation for Embankments (except where a bridging layer is used, as provided for in Clause 3.2.2).
Each layer of material replacing unsuitable material as detailed in Clause 2.4 (except within 300 mm of design level of floor of cuttings).
Foundation Treatment Types E1 and E3, and Working Platforms in embankments specified in Clause 3.2.3.
95.0%
Each layer of material placed in formations up to the underside of the Selected Material Zone, including that in Shallow Embankments and Cut/Fill Transition Zone.
The entire area on the floors of cuttings.
Material in verges or within medians up to the level at which topsoil is placed.
Select Fill placed adjacent to structures, as specified in Clause 5.4.
Other areas not specifically mentioned herein.
98.0%
Materials placed in the “spill-through” bridge embankment zone, as specified in Clause 5.2.1.
100.0%
Each layer of the Selected Material Zone. 102.0%
A Lot must contain only areas of work that are essentially homogeneous. This occurs when material
origin and properties, general appearance, moisture condition during compaction, compaction
technique, response to compactors, and state of underlying materials are substantially alike.
Areas that fail to meet these conditions must be excluded from the Lot and must be tested separately as
one or more additional Lots.
Failure to ensure compliance with these requirements in Lot definition invalidates the compaction
acceptance scheme. Also ensure that changes to Lot boundaries are accounted for in future testing.
7.2.2 Sampling and Testing
Engineers and Surveillance Officers engaged on contract work should be thoroughly familiar with the
requirements and shortcomings of the sampling and testing specified. They should spend some time
with an experienced laboratory technician and a geotechnical scientist in a soils laboratory to fully
understand test results presented. There are many opportunities for errors in sampling and testing
techniques which can result in erroneous results.
Particular care is needed to ensure that samples are taken to the full depth of the layer. Materials
may not be uniform through the layer depth, particularly in general earthworks. While strictly this is
in breach of the specification requirements, some variation in material properties is inevitable and can
be tolerated provided it is not too extreme. Sampling and testing of the full depth is necessary to
ensure that compaction requirements are being met.
Ensure that the laboratory independently carries out its responsibilities, as detailed in TfNSW Q, for
locating and carrying out sampling and testing.
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Provide a smooth surface at each sampling location for the purpose of obtaining samples.
The PROJECT QUALITY PLAN must ensure that Lots are inspected for homogeneity as defined in
TfNSW Q Annexure Q/L Clause L1.
At each sample location selected for determination of compaction, carry out a field density test and a
field moisture test and obtain a sample for a laboratory maximum dry density test.
Carry out field (insitu) density tests in accordance with either Test Methods TfNSW T119 or
TfNSW T173.
Conduct all tests within a particular Lot using only one of the above Test Methods. Do not combine
results obtained from more than one Test Method for a statistical assessment of a particular Lot.
Where Test Method TfNSW T173 is used for the insitu density determination, extend the probe to be
located within the layer and close to the bottom of the nominated layer. Once the test is completed,
take a sample from below the test site, within the circle of area between the probe and the detector and
for the full depth of the nominated layer. The size of this sample must be sufficient for the laboratory
determination of maximum density.
Repair test holes using freshly mixed material of the same type as used in the surrounding earthworks
layer. Compact repair material to a degree equal to that of the surrounding earthworks layer. Detail in
the PROJECT QUALITY PLAN the method of repairing the test holes.
Irrespective of the Test Method used to determine the insitu density, the proportion and density of
oversize material retained on the 37.5 mm AS sieve in the sample for the laboratory maximum dry
density test must also be determined, in accordance with the procedure described in Test Method
TfNSW T119.
Determine field moisture content in accordance with Test Methods TfNSW T120, TfNSW T121, or
TfNSW T180. Only use TfNSW T121 and TfNSW T180 where results have previously been
calibrated against those of TfNSW T120 for the range of materials being compacted.
Determine maximum density using Test Methods TfNSW T111 or TfNSW T162.
7.2.3 Relative Compaction
Calculate relative compaction using Test Method TfNSW T166.
Round off the relative compaction value and the characteristic relative compaction value to the nearest
0.1%.
7.3 ROCK FILL
Conformity of a Lot of rock fill is based on compliance with the nominated compaction routine
verified in accordance with this Clause, and proof rolling in accordance with Clause 7.4.1.
Develop a materials grading, mixing, watering and rolling routine after construction and testing of trial
sections, and nominate the verified routine to the Principal. If the routine includes insitu modification
(e.g. with a grid roller or similar), then verify the after-compaction grading of the material.
The length of a trial section must not exceed 50 m, and the width must be greater than or equal to 2
times the maximum roller drum width. Do not construct trial sections within 1.5 m of the bottom of
the Selected Material Zone.
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Verification of a compaction routine will be based on results from two (2) successive trial sections.
Two contiguous trial sections, constructed over the same time period in a continuous operation, will
not be deemed to be two successive trial sections.
The compaction routine must include at least one vibrating roller.
WITNESS POINT
Process Witnessed: Construction of each trial section of rock fill
Submission Details: Notification of the place, date and time of construction of the trial section, at
least 3 working days prior to commencement with details of:
(i) Test results of all previous trial sections;
(ii) Material type(s) and specifications, including moisture conditioning
prior to and during rolling;
(iii) Plant types and specifications;
(iv) Number of roller passes;
(v) Maximum and minimum roller speed and frequency of vibration;
(vi) In-process testing regime and proof that there is no remaining internal
settlement and proof that embankment stability exists.
HOLD POINT
Process Held: Compaction of rock fill.
Submission Details: Verification, including test results, of conformity of each trial section
including details of the proposed compaction routine, any test results and
survey reports.
Release of Hold Point: The Principal will consider the submitted documents, prior to authorising the
release of the Hold Point.
Where in-process testing of the compaction routine reveals nonconforming results, cease placing and
compacting, and redevelop the routine using trial sections in accordance with the above or break down
and/or sort rock material to achieve an earth fill in accordance with Clause 5.2. The above Hold Point
applies to the redeveloped routine prior to recommencement of placement and compaction operations.
All costs associated with the development and nomination and verification of the compaction routine,
and the utilisation of the nominated compaction routine on rock fill layers is deemed to be included in
the rate for General Earthworks.
7.4 DEFLECTION TESTING
7.4.1 Proof Rolling
All embankment Lots, and all other surfaces within 1.5 metres of the underside of the Selected
Material Zone must be capable of withstanding proof rolling to verify their stability.
Unless otherwise approved by the Principal, undertake proof rolling in accordance with Test Method
TfNSW T198 in the presence of the Principal.
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This clause is not intended to require proof rolling of every lift. It specifies the method by which proof
rolling should be done and when it is required. This should only be where there is a need to confirm
the stability of the formation as a platform for further construction. The procedure is T198. This
specifies the plant to be used. Alternative plant can be used providing it applies a loading at least
equivalent to that specified. Whilst the requirement is that each layer “must be capable…”, the
testing is not mandatory and is usually only required if instability and “heaving” are suspected.
The moisture content of the compacted material being proof rolled must be within the range specified
in Annexure R44/A5. Proof roll each layer immediately following compaction. For the purpose of
deflection testing by proof rolling, take the testing paths along the full width and length of each Lot.
WITNESS POINT
Process to be Witnessed: Proof rolling of any embankment fill layer, or any other surface within 1.5
metres of the underside of the Selected Material Zone.
Submission Details: At least 1 working day’s notice of intention to proof roll any surface with the
proof rolling plan and verification of the layer or surface conforms (except
proof rolling).
The tests must not exhibit visible deformation, rutting, or yielding and/or show signs of distress or
instability.
If further proof rolling is required at a later date, the layer must be re-conditioned such that the
moisture content is within the range specified in Annexure R44/A5, re-verified as conforming for
density and survey requirements of this Specification, and given not less than eight (8) passes with the
roller to be subsequently used for the proof rolling operation.
7.4.2 Benkelman Beam
Where shown in Annexure R44/A4, carry out deflection testing following completion of the formation
to the underside and top of the Selected Material Zone (or underside of pavement where no Selected
Material Zone is specified) using the Benkelman Beam in accordance with Test Method TfNSW T199.
Where the required characteristic deflection does not exceed 1.2 mm, the standard deviation of the Lot
must not exceed 0.2 mm. If the required characteristic deflection exceeds 1.2 mm, the coefficient of
variation of the Lot must not exceed 25%.
Limiting the deflection of the formation under the pavement limits the amount of deflection which must
be withstood by the pavement in service. If deflections are too high for a particular pavement design,
premature failure will occur.
The CV requirement will need to be reconsidered where deflections are very low, e.g. a Lot with a
mean deflection of 0.5 mm and SD of 0.2 mm will fail, with a CV of 40%, even though there may not
be a single deflection greater than 1.0 mm. A Lot with a mean of 0.8 mm and the same SD would pass
the CV requirement.
For the purpose of deflection testing with the Benkelman Beam, a Lot must consist of a continuous
length of formation of at least 300 m and of at least a single carriageway width that is generally
homogeneous with respect to material and appearance. In urban areas or area with severe restrictions,
the Principal may reduce the length of the Lot. Mark the boundaries of each Lot such that they are
clearly identifiable in the field.
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Take deflection testing by Benkelman Beam within 3 days of compaction of the material. Undertake
testing over the plan area of the Selected Material Zone within each Lot and any other area within the
Lot as directed by the Principal.
Obtain the Characteristic Deflection for each Lot from the equation:
CD = u + f.σ
where CD = Characteristic Deflection
u = average maximum deflection
f = value as shown in Annexure R44/A4
σ = standard deviation
Where the characteristic deflection exceeds the value in Annexure R44/A4, re-examine the Lot
boundaries, re-check the Lot for homogeneity, and subsequently re-nominate the Lot (or parts thereof)
for further testing.
WITNESS POINT (when Benkelman Beam Testing is specified)
Process to be Witnessed: Benkelman Beam testing of the surface under the first layer of pavement.
Submission Details: Notification of time, date and location of Benkelman Beam testing and
results of proof rolling at least 1 working day prior to the proposed date of
Benkelman Beam testing.
HOLD POINT
Process Held: Placing each Lot of Selected Material Zone or pavement (where there is no
Selected Material Zone).
Submission Details: Deflection test results, Survey Report of the finished surface and verification
of conformity of each Lot of formation at least 3 working days before the
work is programmed to be covered up.
Release of Hold Point: The Principal will consider the submitted documents, and may direct further
action prior to authorising the release of the Hold Point.
7.5 LEVEL CONTROL
7.5.1 Tolerances
Finish the surface levels of the floors of cuttings, transitions, earthworks layers and zones, and verges
to the design surface levels less the nominated thicknesses of the relevant overlying courses and zones
to within the tolerances detailed in Table R44.12.
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Table R44.12 – Level Control - Tolerances
Position Tolerance
(a) Top of Selected Material Zone or top of formation where there is no Selected Material Zone:
(i) where overlying layer is part of the Contract, and quantity for payment for overlying layer is in units of square meters
(ii) where overlying layer is part of the Contract, and quantity for payment for overlying layer is in units of cubic meters
(iii) where overlying layer is not part of the Contract
+0 mm / –20 mm
+0 mm / –20 mm
+0 mm / –20 mm
(b) Formation at level of underside of Selected Material Zone:
(i) where underlying layer is a drainage layer in a cutting
(ii) all other cases
+0 mm / –20 mm
+0 mm / –20 mm
(c) Surface of verges +0 mm / –20 mm
(d) Floor of cutting before carrying out foundation treatment:
(i) Type C1 - Loosen and compact
(ii) Type C2 - Excavate and backfill
(iii) Type C3 - Working platform
(iv) Type C4 - Geotextile and geogrids
(v) Type C5 - Drainage layer
+0 mm / –20 mm
+0 mm / –100 mm
+0 mm / –100 mm
+0 mm / –20 mm
+0 mm / –100 mm
(e) Top of foundation treatment under embankment
(i) Type E3 - Working platform
(ii) Type E5 - Drainage layer
+20 mm / –20 mm
+20 mm / –20 mm
(f) Floor of terrace at Cut/Fill Transition +0 mm / –100 mm
(g) Floor of benching in cuttings +0 mm / –100 mm
(h) Top of rock fill +0 mm / –100 mm
7.5.2 Areas Below Level Tolerances
Where the overlying layer is not part of the Contract, and the finished surface level of the top of the
Selected Material Zone is not higher than the upper limit of the tolerance shown in Table R44.12
(+0 mm), but is lower than the lower limit of the tolerance (-20 mm), the work may be accepted by the
Principal, under the following conditions:
(a) Deductions are made at the rate shown in Annexure R44/A6;
(b) Your methods for carrying out the survey and calculation, and the calculated values, are agreed
to by the Principal.
7.5.3 Median Areas
The batter slopes for median areas must comply with those shown on the Drawings and undulations in
the general plane of the batter slope will not be permitted outside of the following tolerances.
For a horizontal distance of up to 2 m from the edge of the shoulder (except areas where verges are
required), no point on the completed batter may vary from the specified slope line by more than
35 mm when measured at right angles to the slope line. At distances greater than 2 m horizontally
from the edge of the shoulder, no point on the completed batter may vary from the specified slope line
by more than 75 mm when measured at right angles to the slope line.
Notwithstanding the tolerance of construction above, grade medians so as not to pond water.
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ANNEXURE R44/A – PROJECT SPECIFIC INFORMATION
NOTES TO TENDER DOCUMENTER: (Delete this boxed text after completing Annexure A)
Review the default values shown in Annexure A and amend if appropriate, fill in the missing details as
required, and delete as applicable where “Yes/No” options are provided in Annexure A, taking into
account the geotechnical information and the pavement design for the project.
For Annexure A1, consult TfNSW Survey Section on the practicality of the surveys.
These requirements must be complied with when compiling tender documents. They should be project
specific requirements and be based on a thorough knowledge of the site, the expected materials and
the makeup and availability of the site team and available personnel, i.e. it is a plan which is
considered practical and which TfNSW’s site team, as well as the Contractor, will be expected to
follow during the course of the contract. Engineers should consult with survey staff on the practicality
of these surveys.
A1 SURVEYS (Clause 1.6)
Carry out surveys and joint surveys (in accordance with TfNSW G71) where required in the following
table:
Clause Location Survey Joint
Survey
Model File (1)
2.3.2 Topsoil stockpile site before stockpiling Yes Yes Yes/No
2.3.3 Surfaces of each cutting and embankment after
stripping of topsoil
Yes Yes Yes/No
2.4 Before removal of unsuitable material Yes No Yes/No
2.4 After removal of unsuitable material Yes No Yes/No
4.4, 5.4 Completed cut and fill batters prior to
topsoiling, vegetation or other treatments
Yes No Yes/No
5.1, 6.1.1 Surfaces prior to placing imported material Yes Yes Yes/No
6.1.2 Surfaces prior to placing Selected Material Yes No Yes/No
6.2 Before placing verge material Yes No Yes/No
7.5.1 Floor of cutting before placing foundation
treatment materials or formation
Yes No Yes/No
7.5.1 Top of finished Formation Yes Yes Yes/No
7.5.3 Finished surface of median Yes No Yes/No
Note:
(1) If this requirement is “Yes”, the survey report must include a computer file containing data in a format that
is suitable for creating accurate models using the current standard TfNSW CADD software.
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A2 MATERIALS
A2.1 Sources
Clause Description Requirement
2.3.1 Topsoil
2.3.1(i) - Stockpile within the Site Yes/No
2.3.1(ii) - Stockpile as a windrow Yes/No
2.3.1(iii) - Spoil outside the Site Yes/No
2.3.1(iv) - Spoil as contaminated material Yes/No
2.7.2 Borrow sites
- Specified location ………………….
- Maximum batter slope of borrow site excavation ……..
2.8.1 The following materials must only be from imported sources:
- Upper Zone of Formation material other than Selected
Material
Yes/No
- Selected Material Yes/No
- Verge material Yes/No
3.2.3, 3.4.3 - Working Platform stabilized material Yes/No
Sources of imported material:
2.8.2.2 - Upper Zone of Formation material other than Selected
Material
………………….
2.8.3.2 - Selected Material Zone material ………………….
2.8.4.2 - Verge material ………………….
5.1 - Imported fill ………………
3.2.3, 3.4.3 - Imported stabilized material ………………
6.1.2 Material in the Selected Material Zone at any location must be
from the same source (1)
Yes/No
Note:
(1) If this requirement is “Yes”, the material placed in the upper layer of the Selected Material Zone at any
particular location must be from the same source, produced using the same process and exhibit similar
properties prior to any chemical modification which may be required, as that placed in the lower layer at
that same location.
A2.2 Properties
All material properties to be entered below are site specific. The properties, Test Nos and values
entered should be chosen so that the best use is made of available materials.
The choice of 4 or 10 day soaks for CBR values should only be made after gaining knowledge of site
materials. Some very fine materials will have a high CBR value at 4 days soak but will deteriorate
after further soaking and the CBR at 10 days can be significantly less than at 4. Whilst a test done
after 4 days soak may give a quick answer, the four day soak result may not properly represent the
material properties in service. As a guide, 4 day soak will be specified for granular materials and 10
day soaks will be specified for lower permeability silts and clays.
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In a practical sense, the specified tests are meant to provide an indication of the suitability or
otherwise of materials before placement in each zone. They are an indication only. Most materials
break down to a degree during excavation, haulage, spreading, mixing with water or other material,
drying, compacting and trimming and many will provide a significantly different test result after these
operations have taken place and the material is in place in its specified zone. Pre-treatment and
accelerated weathering tests should be carried out prior to placement in a zone, in order to best
predict its behaviour in place. (See Note 1 below table.
Clause Location Value Test Pre-treatment
(1)
2.8.2, 3.5
Material for Upper Zone of Formation other than Selected Material, including at Shallow Embankment and Cut/Fill Transition:
a) CBR10 day (2) 8 min T117 T102/T103 (3)
b) Plasticity Index 25 max T109 T102/T103
2.8.3.1 Site won Selected Material:
a) Selected Material Zone top 150 mm layer CBR4 day (2), characteristic value (Q) (3) Refer Note 4
30 min (4) T117 T102/T103 (5)
b) rest of Selected Material Zone CBR4 day (2), characteristic value (Q) (3) Refer Note 4
15 min (4) T117 T102/T103 (5)
c) Plasticity Index 15 max T109 T102/T103 (5)
2.8.4 Verge material:
a) CBR4 day (2) 15 min T117 T102/T103 (5)
b) Plasticity Index 6 and 12 T109 T102/T103 (5)
3.5 Foundation of Shallow Embankment and Cut/Fill Transition where depth of excavation less than specified:
a) CBR10 day (2) 8 min T117 T102/T103 (5)
b) Plasticity Index 25 max T109 T102/T103 (5)
3.4 Floor of Cutting:
a) CBR10 day (2) 8 min T117 T102/T103 (5)
b) Plasticity Index 25 max T109 T102/T103 (5)
3.2.5, 3.4.5
Drainage Layer (Foundation Treatment Type E5 and C5):
a) Point Load Strength Index Is(50) 1 MPa min T223 NA
b) Wet/Dry Strength Variation 35% max T215 T102
3.4.2 Backfill material for Type C2 Foundation Treatment:
a) CBR10 day (2) 8 min T117 T102/T103 (5)
b) Plasticity Index 25 max T109 T102/T103 (5)
5.2.1 Earth fill at “spill-through” bridge abutment zone:
Material Type ST1, for waterway crossings
a) CBR10 day (2), characteristic value (Q) (3) 8 min T117 T102/T103 (5)
b) Plasticity Index 15 max T109 T102/T103 (5)
Material Type ST2, for overbridges
a) CBR10 day (2), characteristic value (Q) (3) 8 min T117 T102/T103 (5)
b) Plasticity Index 25 max T109 T102/T103 (5)
5.3.2 Rock fill:
a) Point Load Strength Index Is(50) 1 MPa min T223 NA
b) Wet/Dry Strength Variation 35% max T215 T102
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Clause Location Value Test Pre-treatment
(1)
5.5 Rock facing:
a) Point Load Strength Index Is(50) 1 MPa min T223 NA
b) Wet/Dry Strength Variation 35% max T215 T102
Legend: NA = not applicable max = maximum min = minimum
Notes:
(1) Pre-treatment is not required where samples are taken from the compacted formation.
(2) Compaction for CBR test must be at 100% of MDD under standard compaction.
(3) When calculating CBR characteristic value, report values calculated to the nearest 1%.
(4) (Refer Clause 2.8.3.1.) If any Lot of Selected Material in the top 150mm layer has a CBR less than the value specified above, the material must be modified with hydrated lime at an application rate of 2% by mass. The modified material must have a UCS of less than 1.5MPa, when tested in accordance with TfNSW T131 using 7 days accelerated curing. Other suitable binders may be used where approved by the Principal. However, do not use binders which are prone to give rise to rapid or uneven strength gain or excessive shrinkage.
(5) Where pre-treatment is shown as “T102/T103”, determine the appropriate pre-treatment regime for the material in accordance with Clause 2.8.1.
The intention of Note (4) is that CBR values are selected to make best use of available materials and
that the Contractor should be able to achieve the result using the naturally occurring materials by
taking reasonable care. The option of stabilising in this specification is one which recognises that the
Contractor may actually not finish up with the required material quality. Stabilisation is usually an
option available which would improve the quality and reduce the moisture-susceptibility of the
particular material.
Whilst 2% lime is specified here together with a minimum UCS, other stabilising agents and
properties may be specified. In each case, the treatments and material properties need to be tailored
to suit the material available and the pavement design for the project. The pavement is generally
designed on the CBR of the material prior to modification on the assumption that in the long term the
lime may be leached from the SMZ.
Where the CBR in the SMZ is less than CBR = 30%, the 2% lime will reduce moisture susceptibility
during construction, will reduce the risk of pavers getting bogged and is consistent with achieving an
increase in strength upwards through the Upper Zones of Formation.
Care should be exercised, and Pavements Branch help sought, if a contractor proposes to use Steel
Furnace Slag (SFS) or other waste product materials as a pavement, SMZ or Upper Zone material.
SFS is prone to expansion when exposed to moisture in a pavement layer if not properly weathered for
at least three to four months beforehand. This comment does not apply to Blast Furnace Slag which
has successfully been used as a pavement material in a number of regions.
A3 FOUNDATION TREATMENT
Clause Description Requirement
3.2.2 Type E2 Foundation Treatment - Bridging Layer
- Minimum depth from underside of pavement to top of bridging
layer 600 mm
- Maximum thickness of bridging layer 800 mm
3.2.5 Type E5 Foundation Treatment - Drainage Layer
- Completed thickness of drainage layer 300 mm
(+100 mm, –0 mm)
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
NR44 Guide to R44 Earthworks
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3.2, 3.4 Specified Foundation Treatments
- Location ‘A’ Type: …………..
- Location ‘B’ Type: …………..
A4 SHALLOW EMBANKMENT, CUT/FILL TRANSITION, UPPER ZONE OF
FORMATION AND VERGES
Job specific dimensions should be entered here.
Clause Description Requirement
3.2, 3.5.1 A Shallow Embankment exists where the height from the Stripped
Surface Level to the Top of Formation is less than: 1,200 mm
6.1 Thickness of Upper Zone of Formation (incorporating Selected
Material Zone) for:
- Cutting 300 mm
- Cut/Fill Transition Zone 1,200 mm
- Embankment 600 mm
- Shallow embankment 1,200 mm
6.1.2 Selected Material Zone:
- Thickness 300 mm
2.8.3.1 - Depth for modification of material, other than to only meet
specified CBR requirements
6.1.2 Maximum compacted thickness of each layer in the Selected
Material Zone:
150 mm
6.2 Compacted layer thickness of each layer of verge material 100 mm – 200 mm
7.4.2 Monitor deflection at underside and top of Selected Material Zone
with Benkelman Beam.
Yes/No
7.4.2 Maximum Characteristic Deflection (CD) recorded for any Lot
must not exceed:
- Top of Selected Material Zone 1.0 mm
- Underside of Selected Material Zone 1.2 mm
- Factor “f” to be used in determining CD 1.65
7.5.2 Deduction to be applied for out of tolerance surface level where
the overlying layer is not part of the Contract
……..
3.5.1 The removal of material from the transition zone is designed to address the often poor quality of
the natural material occurring in that zone. It is, by its nature, naturally occurring material near the
surface of the earth and is often weathered and of poor or variable quality. There are cases where the
cut/fill transition can extend over a great length and careful consideration should be given to the need
to specify its special treatment as a location needs to be found for the material excavated. The depth
of 900mm has been chosen as this is the depth from finished pavement level (approx 1500mm) which
would normally be affected by heavy vehicles travelling on a granular pavement. In order to be cost
effective, the pavement and earthworks need to be considered together.
(TfNSW COPYRIGHT AND USE OF THIS DOCUMENT - Refer to the Foreword after the Table of Contents)
Guide to R44 Earthworks NR44
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6.1 The depths of materials in the upper zone of formation, including the select material zone needs to
be chosen to suit the best usage of available materials and the pavement design for the work. These
depths are site specific and should be chosen after careful consultation with geotechnical staff and
with due consideration of practicality and cost. The specifying of a select material zone is done to
ensure the most appropriate cost effective material is reserved for the surface immediately beneath the
pavement layers. The specifying of a deeper upper zone of formation in fills is done to try and ensure
the better materials available during earthworks excavation from cuttings (usually from towards the
bottom of cuttings), are utilised towards the tops of fills where they will experience the highest traffic
loading.
As explained above, deflections will change with time and moisture content. It will be in the
Contractor’s interests to measure some time after compaction, after no site traffic and after a dry
period of weather. Constraints are placed on the timing of deflection testing in both Clause 7.4.2 and
T199. If it is expected that this issue will be critical, further constraints should be specified.
There may be circumstances where requiring Benkelman Beam readings to be taken at the top of the
SMZ in addition to the underside of the SMZ can be waived but not without seeking prior Pavement
Branch advice.
The shape of the deflection bowl, measured during Benkelman beam readings, will provide a better
indication of quality and will indicate whether any “soft” layer is near the surface or some depth
below it.
A5 COMPACTION MOISTURE REQUIREMENTS (Clause 7.2)
Material Description (1) Source / Location Moisture Range (2)
Earthworks Material 60 – 90%
Notes:
(1) Material types above are project specific.
(2) The Moisture Range is expressed as the ratio of Field Moisture Content to Optimum Moisture Content at
standard compactive effort and is reported as a percentage.
Project specific requirements should be entered here. Whilst 60-90% will generally provide a
satisfactory result, it is conservative from TfNSW’s viewpoint.
In general, there will be difficulties compacting materials at moisture contents below 60% of optimum
and in any case, water will probably need to be added for dust control. It may not be practicable for
many materials to be compacted below 90% of optimum moisture content, particularly with heavy
clays in high rainfall or low-lying areas which are often at or above this moisture content in situ.
Consideration needs to be given to allowing higher moisture contents where this occurs and
permitting its placement at some depth in the fill, where it would not adversely affect the finished
Benkelman Beam testing at underside of the Selected Material Zone. Hold Point
7.4.2 TfNSW T199 R44/A4 7.4.2, R44/A4
Benkelman Beam testing at top of the Selected Material Zone. Witness Point / Hold Point
7.4.2 TfNSW T199 R44/A4 7.4.2, R44/A4
13. Level Control 7.5
Surface levels of Selected Material Zone, formation, floor of cutting, drainage layer, working platform, cut/fill transitions, benches in cuttings, rock fill and verges
7.5.1 Survey TfNSW G71 7.5.1
Median areas 7.5.3 Survey TfNSW G71 7.5.3
14. Spoil 2.5
14.1 Non-contaminated Materials 2.5.1
Authorisation given within the site 2.5.1 Each location Authorised