Kingscote Streets Upgrades - Kangaroo Island Council

On completion of construction of the scour protection apron the surrounding ground disturbed during
the works shall be reinstated by filling as necessary and grading to conform to adjacent ground
conditions.
4.3.21 Connection to Existing Drain
Construction of the design drains includes connecting to the existing drain or drains in the locations
shown on the drawings.
Design information provided on the location of existing drainage lines and structures may not be
sufficiently accurate and is based in situ construction. The use of precast drainage structures shall
be at the Contractor's risk.
The Contractor shall ensure that interference with an existing drain does not impede the functioning
of that drain, and the Contractor shall program the work to take account of likely flows and shall take
all necessary measures to handle the existing flows and any consequences arising from the
temporary interference shall be the responsibility of the Contractor.
The connection of the design drain to the existing drain shall be constructed to the details shown on
the drawings.
4.3.21.1 Connection to Existing Concrete Channel, Pipe, Box Culvert or Junction Box
The connection of the design drain to the existing concrete structure shall be a direct connection
through the wall of the existing structure. The hole to accommodate the design drain shall be made
in the wall of the structure using cutting or drilling tools as approved by the Superintendent to give a
neat opening.
The design drain shall be let into the hole so made and the joint shall be grouted in using a 1:3
cement and sand mortar trowelled to a smooth surface. The end of the design drain shall be cut and
trimmed so that the joint is finished flush with the internal wall of the existing structure.
To ensure adhesion of the jointing materials, the end of the drain and the surface of the wall of the
existing structure shall be thoroughly cleaned off and saturated with water before the joint is made.
A concrete bandage shall be placed around the joint on the external surfaces.
All concrete work shall be in accordance with the requirements of the Concrete and Concrete Work
section of this specification.
4.3.21.2 Connection by New Junction Box
The connection of the design drain to the existing drain shall be at a new junction box to be
constructed on the existing drain.
The existing drain shall be exposed by excavation at the required location, and a junction box
constructed to the details shown on the drawings. The portion of the existing drain within the
junction box shall be broken out and removed. The ends of the existing drain shall be cut and
trimmed such that the joints are finished flush with the internal walls of the new junction box.
Alternatively, and subject to the prior approval of the Superintendent, the Contractor may elect to
remove the portion of the existing drain no longer required by the design conditions prior to the
junction box construction.
The joints between the ends of the existing drain and the walls of the junction box shall be grouted in
using a 1:3 cement and sand mortar trowelled to a smooth surface.
The construction of the junction box shall comply with the requirements of the Drainage Structures
clause in this section of the specification.
4.3.21.3 Connection to Existing Open Earth Channel
The connection of the design drain to the existing open earth channel shall be made by the
construction of a reinforced concrete headwall at the end of the design drain.
Ref No. 20120236SA1 Kingscote Streets Upgrades Technical Specification 19