(1) Scope
The Section covers the
clearing and grubbing necessary for the construction of the works covered by
the contract. Conservation of the top soil and flora is also covered under this
Section.
(2) Description of Work
(a) Clearing
Clearing shall consist of the cutting, removing and disposal of all tree,
bushes, shrubs, grass, weeds, other vegetation, anthills, rubbish, fences, top
organic soil not exceeding 150 mm in thickness and all other objectionable
material, resulting from the clearing and grubbing. It shall also include the
removal and disposal of structures that obtrude, encroach upon or otherwise
obstruct the work. The moving of a certain amount of soil or gravel material
may be inherent to or unavoidable during the process of clearing and no extra
payment shall be made for this. Clearing shall include the removal of all rocks
and boulders of up to 0.15 m 3 in size exposed or lying on the surface.
(b) Grubbing
In the roadway all trees up to 300 mm girth, stumps and roots shall be
removed to a depth of not less than 900 mm below the finished road level and a
minimum of 500 mm below the original ground level whichever is lower. Except in
borrow areas the cavities resulting from the grubbing shall be backfilled with approved
material and compacted to a density not less than the density of the surrounding
ground.
(c) Conservation of Top Soil
Where suitable topsoil exists within the limits of the area to be cleared
and grubbed, the Contractor shall, if ordered by the Engineer, remove the
topsoil together with any grass and other suitable vegetation. If not used immediately,
the topsoil shall be transported and deposited in stockpiles for later use.
(d) Conservation of Flora
Where provided for in the contract, certain designated flora encountered in
the road reserve and borrow areas shall be carefully protected by the
Contractor. In his tendered rate for Site Clearance, he shall include for the
careful removal and planting of the flora in a protected and fenced-off area
and, on completion of the road, for the replanting of the flora in suitable
positions in the road reserve in accordance with the Engineer’s instructions.
(3) Execution of Work
(a) Areas to be Cleared and Grubbed
Stumps, embedded logs, roots and all other vegetation growth and
accumulated rubbish of whatsoever nature and all other objectionable material
shall be completely removed to a depth as specified. Normally the portions of the road reserve that fall within the limits of
the road prism, as well as certain borrow areas shall be cleared and/or
grubbed. Where the road reserve is to remain unfenced, the full width of the road reserve shall be cleared
and/or grubbed except for such trees designated by the Engineer to be
left standing and uninjured. The Contractor shall mark the
boundaries of the area for clearing and grubbing and seek the approval of the
Engineer before commencement of the work. The Engineer shall designate in detail
the exact areas to be cleared, and grubbed and the time at which it shall be
done.
(b) Cutting of Trees
The Contractor shall take the necessary precautions to damage to structures
and other private or public property. If necessary, trees shall be cut in sections
from the top downwards. The branches of trees to be left standing shall be
trimmed so as not to intrude into a space of 7m above the roadway. Such
individual trees as the Engineer may designate and mark in white paint shall be
left standing and uninjured. In order to minimize damage to trees that are to
be left standing, trees shall be felled towards the center of the areas being
cleared, if so required by the Engineer. Permission for cutting trees must be
obtained from the competent authority who may require that trees be numbered,
measured and marked in the presence of officials from that authority. Cutting
of such trees shall then be carried out by the Contractor and the timber stored
at designated locations. Felling and cutting of trees on the site and pilling
them off the site shall conform to the requirements of the competent authority.
All tree trunks and branches in excess of 150 mm in diameter shall be cleaned
off, secondary branches cut into suitable length and stacked at sites indicated
by the Engineer. Such timber shall not be used by the Contractor for any purpose
and shall remain the property of the Employer. All timber except such timber as
can be used and all brush, stumps, roots, rotten wood and other refuse from the
clearing and grubbing operations shall be completely removed from within the
Right of Way.
(c) Dealing with Anthills
Where anthills are encountered within the limits of the road prism, they
shall be excavated to a depth of not less than 750 mm below the finished road
level and the material carted to spoil. Cavities resulting from the clearance
of anthill material shall be backfilled with approved material and compacted to
a density not less than that of the surrounding ground. Where directed by the
Engineer, the area covered by anthills shall be treated, after excavation and
before backfilling of cavities, with an approved ant control chemical. Payment
for such treatment shall be made in the manner specified in the contract.
(d) Disposal of Material
Material obtained from clearing and grubbing shall be disposed off in
borrow pits or other suitable places and be covered up with soil or gravel as
directed by the Engineer. The burning of combustible material shall not,
normally, be permitted and may only be done with the prior written approval of
the Engineer. Where fences have to be taken down, fencing wire shall be neatly
wound into reels and all such wire, together with all fence posts and other
serviceable material from structures, etc., shall be stacked at sites indicated
by the Engineer.
(e) Re clearing of Vegetation
When portions of the road reserve, borrow or other areas have been cleared
in accordance with the Specifications, but in the course of time, vegetation
grows again during construction, the Engineer may, if he considers it
necessary, order that the area be re cleared. Before the bottom layer of the
embankment is made, the Contractor shall grub up and remove any vegetation that
may in the meantime have grown on the surfaces previously cleared and grubbed. Such
re clearing of areas previously cleared include the removal and disposal of grass,
shrubs and other vegetation in the same manner as for the first cleaning operation.
No separate payment shall be made for re clearing of vegetation.
(4) Measurement
Clearing and grubbing executed as per this Specification shall be measured
in square meter. Cutting trees including removal of stumps and their roots of
girth above 300 mm and backfilling to required compaction shall be measured in
number according to the sizes given below:
(a) Above 300 mm to 600 mm
(b) Above 600 mm to 900 mm
(c) Above 900 mm to 1800 mm
(d) Above 1800 mm to 2500 mm
(e) Above 2500 mm to 3000 mm
(f) Above 3000 mm
For this purpose, girth shall be measured at a height 1 meter above the ground.
Cutting of trees up to 300 mm girth including removal of stumps and roots and backfilling
of holes with compaction shall not measure separately.
(5) Payment
Clearing and grubbing and cutting trees shall be paid at their respective
contract unit rates which shall be the full and the final compensation to the
Contractor. The contract unit rate for cutting of trees of girth above 300 mm
shall also include handling, salvaging, piling and disposing off the cleared
materials with all leads and lifts.
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