This work shall consist of the removal and satisfactory
disposal of all material excavated for the construction of streets
and drainage structures. It shall also include the formation of embankments
and cleaning of slopes.
Roadway excavation shall be done in accordance
with the following requirements:
A. Water. When necessary, ditches shall be provided and
maintained to prevent free water from becoming incorporated in material
to be used to form embankments. Ditches or other means shall also
be provided to prevent water containing suspended solids from flowing
onto private property or existing Town streets.
B. Organic material. Trees, stumps, sod or other organic
material shall not be incorporated in embankments and shall be removed
from the roadway limits. Organic material shall not be deposited or
buried on future Town property such as that reserved for open spaces,
easements or street rights-of-way.
C. Frozen material. When frozen material is excavated,
it shall not be incorporated within roadway embankments. It may be
placed on embankment slopes.
D. Placement of embankment.
(1) No embankment layer shall be placed on surfaces of
snow or ice, nor shall it be placed on frozen or unstable surfaces.
The depth of each layer shall normally not exceed 12 inches. Where
filling in twelve-inch layers is impracticable, as in the case of
filling in water, the embankment may be placed in one layer to the
point where twelve-inch layers are practicable or as directed by the
Engineer.
(2) The embankment shall be crowned or pitched to provide
drainage at the close of each day's operations.
(3) Embankments to an elevation three feet above free
water at the time of filling shall be constructed of rock or free-draining
material or a mixture of both. Free-draining material shall have not
more than 70% passing the No. 40 sieve and not more than 10% passing
the No. 200 sieve.
(4) No stone over five inches in its greatest dimension
shall be placed within 12 inches of the elevation of the top of the
prepared subbase.
E. Compaction.
(1) The entire area of each layer shall be uniformly compacted
to at least the required minimum density by use of compaction equipment
consisting of rollers, compactors or a combination thereof.
(2) The dry density after compaction shall not be less
than 95% of the dry density for that soil when tested in accordance
with AASHTO 180, Method D, except that the mold used in the test shall
be 6.11 inches high. In this test, material retained on the three-fourths-inch
sieve shall be replaced with material retained on the No. 4 sieve,
as noted as an option in the specifications for this test.
F. Stability. If, after full compliance with the requirements
of these specifications with regard to excavation, placement and compaction
density requirements, a stable embankment has not been obtained, the
contractor shall proceed to perform such corrective work as is necessary
to produce a stable embankment. The corrective work may include removal
and replacement of the embankment in part or completely or any other
work as deemed necessary by the Town Engineer to produce a stable
embankment.