Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

3. Section-300
6.3 Quality Control Checks by AE/EE
C. Do’s and Don’ts
Do’s Don’ts
1. Discourage borrow pits along the road; where
permitted, ridges of minimum 8 m width should be
left at intervals not exceeding 300 m. Small drains
should be cut through the ridges to facilitate
drainage.
2. The depth of borrow pits should be so regulated that
their bottom does not cut an imaginary line having
a slope of 1 vertical to 4 horizontal projected from
the edge of the final section of the bank, the
maximum depth in any case being limited to 1.0 m.
3. Do maintain a camber/ cross fall of 4 percent during
construction for effective drainage and prevention
of ponding of water.
4. The area of the embankment foundation should be
kept dry. Test the material (soil) for its suitability
for use in the embankment at least seven days before
commencement of earthwork. Tests should include
soil. classification test data and data regarding
maximum dry density, OMC, and CBR (soaked and
unsoaked).
5. For widening of existing embankment start earth
work from toe line.
TABLE 301.6 : QUALITY CONTROL CHECKS BY AE/EE
Stage Test Frequency Designation of
Inspecting Officer
A. Top of the (i) Degree of Minimum 3 tests for each km length or part AE
Embankment Compaction thereof; allowable tolerance in test values as
(Before placing (IS:2720 Part 28) per para 6.2. One of the tests shall be carried
Subgrade Layer) out at a depth of 150 mm from the top.
(ii) Surface Regularity
and Transverse
Profile
Random Checking AE
B. Finished (i) Degree of (a) One test for each 300 m length or AE
Subgrade compaction
(IS:2720 Part 28)
part thereof.
(b) One test for each 1000 m length or
part thereof. One of the tests shall be
carried out at a depth of 150 mm
from the top.
EE
(ii) Surface Regularity
and Transverse
Profile/camber/
crossfall and
superelevation
Random Checking EE
1. Do not allow borrow pits within a distance equal to
the height of the embankment subject to a minimum
of 1.5 m from the toe of the road embankment.
2. Do not allow borrow pits within 800 m of towns or
villages.
3. Do not use unsuitable material for embankment
construction (Refer para B.1).
4. Do not allow construction or other vehicular traffic
over the prepared surface of embankment/ sub-grade.
5. Do not place successive layers of embankment until
the previous layer has been thoroughly compacted and
duly approved by Engineer.
6. Do not allow any damage to works, crops or other
property while discharging stagnant water found in
embankment foundation.
7. Do not allow dumping of earth from top to widen an
existing embankment.
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