Earthwork in excavation,Filling and subgrade
Earthwork in
excavation
The work of excavation would
commence as soon as the area under construction has been cleared by survey
team. The excavated material will be transported directly to either of the
followings
n If the soil is suitable for embankment works - would go to
embankment site. Internally transportation distance will be reached
approximately 10km.
n If the soil is suitable for re-handling works of embankment
– would be stocked permitted area then re-handled to site.
n If the soil is not suitable – would be dumped in the
earmarked area. Site investigation will be reported for the approval of
disposal area which is located within 10 Km.
n Required number of tipper for transportation will be
provided as mentioned in construction programme.
The areas where excavated soil
is to be used would be laid to fine lines and levels then will be watered and
compacted as per specifications. To handle the required quantity of earthwork substantial number of
excavators, front-end loaders, dozers and soil compactors would be deployed as
mentioned
Quality
control for Earth work in Excavation
n Excavation for
structures shall consist of the removed of material for construction of
foundation for bridges, culverts, retaining walls, pipe culverts etc.. So in
accordance with the requirements of these specifications, we will carry out
excavation to the full depth of required founding level. Even we shall carry
out the excavation whether a line of vetical to 2 horizontal in stressed zone
from an adjouring structure.
n Where
cofferdams are required, these shall be carried out to adequate depths and
heights which will be safety designed and constructed to make watertight.
n Sufficient
clearance for inspection shall be ensured for construction activities inside
the enclosed area.
n Pumping from
the interior of any foundation enclosure will be done in such a manner as to
preclude the possibility of the movement of water through any fresh concrete.
n Contractor take
all precautions in diverting channel and its discharging the drained water as
not to cause damage to the works or any other property and material.
Earthwork in Filling and subgrade
These method statement can be
apply to the construction of embankment, earthen shoulder and subgrade
Material
The material used in
embankments shall be soil, moorum, gravel or a mixture of these or ant other
material approved by Engineer, and be free of logs, stumps, roots, rubbishs and
any other ingradient likely to deteriorated affect the stability of the
embankment.
And the size of the coarse material shall ordinary not exceed 75mm and the maximum particular size shall not be more than two-thirds of the compacted layer for the embankment
Contractor will list the material of borrowpit in the quality
control laboratory for the identification of right material and with use the
same on approval of Engineer-in-charge.
Operations
Seting out
n The limits of
embankment will be marked by fixing batter pegs on both side at regular
intervals as guides before commencing.
Dewatering
n If any stagnant
water for the excavation and embankment specially near by river or any other place, it will be removed by pumping or bailing
and the area of embankment foundation keep dry.
n 1” ~ 4” engine
type dewatering pump will be provided as need.
Spreading
n The embakment material will be spread and finished in layer
of uniform thickness not exceeding 200mm compacted thickness over the entire
width of embankment by dozer and motor grader, and required quantity of
equipment is mentioned in
n Moisture content of the material will be checked at the site
of placement prior to commencement to compaction, and if found where water is
required to be add, water will be sprinkled uniformly using water tanker
without any flooding, and mixed in soil by blading, discing or harrowing until
uniform moisture content is obtained the depth of the layer.
Compaction
n The compaction will be done with the help of vibratory
roller capacity 8~10 ton static weight with plain or pad foot drum or heavy
pneumatic tyred roller of adequate capacity of achieving required compaction.
n Contractor will demonstrate the efficacy of the equipment, intends
to use by carrying out compaction trials and the procedure to be adopted for
these site trials will be submitted to the Engineer for approval.
n Each layer of the material will be thoroughly compacted to
the densities specified in the MOST specification as following;
l Relative compaction of Embankment shall be not less than 95%
of MLDD (Maximum Laboratory Dry Density)
l Relative compaction of Subgrade and Earthen shoulder shall
be not less than 97% of MLDD
0 Comments
Please do not enter any spam link in the comment box.