Repair to BT roads at Jaggayyapet Lime Stone Mines. - Vizag Steel

2.1.3.4
03 Subgrade and earthen shoulders verge Not less than 1.65 gm/cc
The Engineer may, however, relax these requirements at his discretion taking into account
the availability of materials for construction and other relevant factors.
Highly expansive clays, exhibiting marked swell and shrinkage properties shall not be
used in the subgrade. Where allowed these shall be deposited only in the bottom layers
of the embankment and shall not be permitted in the top 500 mm portion of the
embankment just below the subgrade.
Stripping and storing top soil: In localities where most of the available embankment
materials are no conducive to plant growth, or when so directed by the Engineer the top soil
existing over the embankment foundation shall be stripped to specified depths not
exceeding 150 mm and stored for covering embankment slopes and other disturbed areas
where re-vegetation is desired.
2.1.3.5 Compacting group supporting embankment:
In all cases, the original ground shall be consolidated by rolling, as directed by Engineer,
but with a maximum of six passes of 8-10 tonnes roller.
2.1.3.6
In a case where there is no embankment and only the subgrade is to be constructed
above the original ground and the original ground does not already have a relative
compaction of at least 100%, the same shall be loosened to a depth of 500 mm, watered
and compacted in layers not exceeding 250 mm in loose thickness to the maximum dry
density of the material determined in accordance with IS:2720 (Pt.VII). However, before
relaying and compacting the loosened material, the surface below this level shall be
suitably consolidated as directed by the Engineer but with a maximum of six passes of a 8-
10 tonne roller.
Where so directed by the Engineer any unsuitable material Occurring in the embankment
foundation shall be removed and replaced by approved materials suitably compacted.
Embankment or subgrade work shall not proceed until the foundations for
embankment/subgrade have been inspected by the Engineer for satisfactory condition
and approved.
Spreading material in layers and bringing to appropriate moisture content:
The embankment and subgrade material shall be spread in a uniform thickness over the
entire width of the embankment in layers not exceeding 250 mm in loose thickness.
Succession layers shall not be placed until the layer under construction has been thoroughly
compacted to the requirement set down hereunder.
Moisture content of the material shall be checked at the source of supply and if found less
than the specified for compaction, the same shall be made good either at the source or
after spreading the soil in loose thickness for compaction. Where water is required to be
added in such constructions, water shall be sprinkled from a hose pipe and/or a truck
mounted water-tank capable of applying water uniformly and at controlled quantities to
variable widths of surface but without any flooding.
If the material delivered to the road bed is too wet, it shall be dried, by aeration and
expositor to the sun, till the moisture content is acceptable for compaction. Should
circumstances arise, where owing to wet weather, the moisture content cannot be reduced
to the required amount by the above procedure, work on compaction shall be suspended.
Moisture content of each layer of soil shall be checked in accordance with IS:2720 (Part-II)
and unless otherwise mentioned, shall be so adjusted, making due allowance for
evaporation losses, that at the time of compaction it is in the range of 1 percent above to 2
percent below the optimum moisture content determined in accordance with IS:2720 (Part-