Volume-IF - JantERmantER

DCPL-K4A02
ii)
When the optimum moisture content of soil is relatively low, a
vibrating roller shall be considered to give better
performance for mechanical compaction.
Since the degree of compaction depends on the moisture content of the soil,
a close watch shall be kept on this aspect and corrections done to
optimise the moisture content. The adequacy of the compaction and
moisture content of the soil shall be determined by performing field density
tests and other tests as and when directed by the Engineer and shall
conform to the stipulations laid down in IS:4701.
The cohesionless soil to be used for area filling, should be placed in fully
saturated condition to obtain the maximum possible density. The saturation
moisture content shall be determined by laboratory tests prior to
commencement of work.
Field compaction test shall be carried out at different stages of filling and
also after the fill to the entire height has been completed.
When density measuements reveal soft areas in the construction, further
compaction shall be undertaken at the contractor's cost as directed by the
Engineer. If the required compaction is then not achieved the material in
the soft area shall be removed and replaced by approved material and
compacted in accordance with this specification all to the contractor's
account.
The fill shall be carried out to such dimensions and levels as indicated on
the drawings after the stipulated compaction. The fill will be considered as
incomplete if the desired compaction has not been obtained.
If so specified, the rock as obtained from excavation may be used for filling
and levelling to indicated grades without further breaking. In such an
event, filling shall be done in layers not exceeding 50 cms. approximately.
After rock filling to the approximate level, indicated above has been
carried out, the void in the rocks shall be filled with finer materials such as
earth, broken stone, etc. and the area flooded so that the finer
materials fill up the voids. Care shall be taken to ensure that the finer fill
material does not get washed out. Over the layer so filled, a 100 mm thick
mixed layer of broken material and earth shall be laid and consolidation
carried out by a 12 tonne roller. No less than 12 passes of the roller shall
be accepted before subsequent similar operations are taken up.
3.8.2 Filling in Disposal Areas
Excavated materials if not used in area filling, will be disposed of in
designated disposal areas as directed or as indicated in the drawings. The
earth shall not be dumped haphazardly but shall be spread in horizontal
layers not exceeding 500 mm in thickness and nominal compaction done to
the satisfaction of the Engineer.
All clods shall be broken before placing the fill. Earthmoving machinery
(PCA.774.S034sca) V.II-D2/S-I : 16