SECTION B - Derry City Council

APPENDIX 6/3: REQUIREMENTS FOR EXCAVATION, DEPOSITION, COMPACTION (OTHER THAN
DYNAMIC COMPACTION) ETC.
1 The Contractor is to provide a detailed earth works management plan which will be submitted to the
Department. The Management plan is to include method of run-off from the work areas and details of
mitigation measures against pollution of watercourses before any work commences on site.
2 Earthworks requirements are shown on the following drawings: 073030/GA/14 -21
3 Blasting is not permitted as an alternative to normal excavation methods.
4 Cutting Faces
i. All fill material used to backfill behind the new contractor designed gabion wall and
reinforced earth slopes to consist of clean well graded granular stone, to Designer’s
specification.
ii.
Contractor shall take all necessary measures to ensure that excavations are kept stable and
free from water. Contractor to include for these provisions in his rates as indicated in the
preamble to Bill of Quantities.
iii.
Contractor to be responsible for all costs associated with excavating and back filling to any
over dig due to battered excavations, etc being greater than the net volume required for the
permanent works.
iv.
Slopes in rock cuttings where blocky material is present to be prepared by trimming to form
a stepped, stable face. Closely jointed area to be carried out incrementally as the face is
prepared. Widely jointed areas to be pressure tested with air to remove loose materials.
v. Toe drains shall be installed at the base of the cuttings for collection of run off.
vi.
All cut off drains alongside cuttings shall be completed prior to commencement of any
adjacent earthworks excavations.
vii.
All trimming shall be carried out incrementally.
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