Kingscote Streets Upgrades - Kangaroo Island Council

of 1.0 m to form a key for the fill. The minimum depth for a bench shall be the minimum layer
thickness.
3.3.8.6 Filling Adjacent to Structures
The Contractor shall use equipment and construction techniques to protect adjacent structures from
damage due to filling operations.
Filling is not to be carried out against new concrete structures until fourteen days after placing the
concrete or until such time as may be approved by the Superintendent.
3.3.9 Backfilling of Trenches
3.3.9.1 General
Backfilling of trenches shall be carried out after the pipes, culverts, cables or conduits have been
installed and surrounded as particularly specified.
No backfilling material shall be placed until the Superintendent has approved the work to be covered
and the material to be used for backfilling.
3.3.9.2 Road Reserves
Where a trench is located under an existing or proposed road pavement or where the nearest side of
the trench is within 2.0 m of an existing or proposed road pavement, the trench above the surround
material shall be backfilled using backfilling sand.
Sand shall be placed in layers not exceeding 250 mm uncompacted thickness and each layer shall
be compacted and tested in accordance with this specification. The sand backfill material shall be
placed and compacted to the formation level of the pavement construction or the pavement
restoration works specified.
3.3.9.3 Other Locations
Where the trench is located in a drainage easement, a reserve, a road reserve (but not closer than
2.0 m from an existing or proposed road pavement), the trench above the surround material shall be
backfilled using unclassified fill material which shall be placed in layers not exceeding 250 mm
uncompacted thickness and each layer shall be compacted and tested in accordance with this
specification.
The backfill shall be placed and compacted to the formation level of any specified restoration works
or to the natural surface levels adjacent to the trench, whichever is appropriate.
3.3.10 Filling Behind Kerbs and Gutters
On completion of the construction of the concrete kerbs and gutters, the area behind the kerb shall
be filled with unclassified fill to 150 mm below the top of the kerb and compacted to the density
specified herein.
After construction of the footpath (if any) the area shall be surfaced with 150 mm thickness of lightly
compacted topsoil, garden loam or dolomite as shown on the drawings.
3.4 Quality Requirements – Earthworks
3.4.1 General
The Contractor shall arrange for testing of the compaction of bulk earthworks filling and trench
backfilling. The testing shall be carried out by a NATA accredited laboratory, in accordance with
AS 1289 – Methods of Testing Soils for Engineering Purposes, and all costs will be borne by the
Contractor.
Copies of the test results shall be made available to the Superintendent for his approval prior to the
commencement of construction of any subsequent layer. The Contractor shall programme the
works accordingly and no claims for delays will be considered due to delays in the availability of
such test results to the Superintendent.
Ref No. 20120236SA1 Kingscote Streets Upgrades Technical Specification 9