**Construction Specification 723---Earthfill**

**1. Scope**

The work consists of the construction of earth embankments, other
earthfills, and earth backfills required by the drawings and
specifications.

*Earthfill* is composed of natural earth materials that can be placed
and compacted by construction equipment operated in a conventional
manner.

*Earth backfill* is composed of natural earth material placed and
compacted in confined spaces or adjacent to structures (including pipes)
by hand tamping, manually directed power tampers or vibrating plates, or
their equivalent.

**2. Material**

All fill material shall be obtained from required excavations and
designated borrow areas. The selection, blending, routing, and
disposition of material in the various fills shall be subject to
approval by the engineer.

Fill materials shall contain no frozen soil, sod, brush, roots, or other
perishable material. Rock particles larger than the maximum size
specified for each type of fill shall be removed prior to compaction of
the fill.

The types of material used in the various fills shall be as listed and
described in the specifications and drawings.

**3. Foundation preparation**

Foundations for earthfill shall be stripped to remove vegetation and
other unsuitable material or shall be excavated as specified.

Except as otherwise specified, earth foundation surfaces shall be graded
to remove surface irregularities and shall be scarified parallel to the
axis of the fill or otherwise acceptably scored and loosened to a
minimum depth of 2 inches. The moisture content of the loosened material
shall be controlled as specified for the earthfill, and the surface
material of the foundation shall be compacted and bonded with the first
layer of earthfill as specified for subsequent layers of earthfill.

Earth abutment surfaces shall be free of loose, uncompacted earth in
excess of 2 inches in depth normal to the slope and shall be at such a
moisture content that the earthfill can be compacted against them to
produce a good bond between the fill and the abutments.

Foundation and abutment surfaces shall be no steeper than one horizontal
to one vertical unless otherwise specified. Test pits or other cavities
shall be filled with compacted earthfill conforming to the
specifications for the earthfill to be placed upon the foundation.

**4. Placement**

Earthfill shall not be placed until the required excavation and
foundation preparation have been completed and the foundation has been
inspected and approved by the engineer. Earthfill shall not be placed
upon a frozen surface nor shall snow, ice, or frozen material be
incorporated in the earthfill matrix.

Earthfill shall be placed in approximately horizontal layers. The
thickness of each layer before compaction shall not exceed the maximum
thickness specified in section 8 or shown on the drawings. Materials
placed by dumping in piles or windrows shall be spread uniformly to not
more than the specified thickness before being compacted.

Hand compacted earth backfill shall be placed in layers whose thickness
before compaction does not exceed the maximum thickness specified for
layers of earth backfill compacted by manually directed power tampers.

Earth backfill shall be placed in a manner that prevents damage to the
structures and allows the structures to assume the loads from the earth
backfill gradually and uniformly. The height of the earth backfill
adjacent to a structure shall be increased at approximately the same
rate on all sides of the structure.

Earthfill and earth backfill in dams, levees, and other structures
designed to restrain the movement of water shall be placed to meet the
following additional requirements:

\(a\) The distribution of materials throughout each zone shall be
essentially uniform, and the earthfill shall be free from lenses,
pockets, streaks, or layers of material differing substantially in
texture, moisture content, or gradation from the surrounding material.
Zone earthfills shall be constructed concurrently unless otherwise
specified.

\(b\) If the surface of any layer becomes too hard and smooth for proper
bond with the succeeding layer, it shall be scarified parallel to the
axis of the fill to a depth of not less than 2 inches before the next
layer is placed.

\(c\) The top surface of embankments shall be maintained approximately
level during construction with two exceptions: A crown or cross-slope of
about 2 percent shall be maintained to ensure effective drainage, or as
otherwise specified for drainfill or sectional zones.

\(d\) Dam embankments shall be constructed in continuous layers from
abutment to abutment except where openings to facilitate construction or
to allow the passage of streamflow during construction are specifically
authorized in the contract.

\(e\) Embankments built at different levels as described under (c) or
(d) above shall be constructed so that the slope of the bonding surfaces
between embankment in place and embankment to be placed is not steeper
than 3 feet horizontal to 1 foot vertical. The bonding surface of the
embankment in place shall be stripped of all material not meeting the
requirements of this specification and shall be scarified, moistened,
and recompacted when the new earthfill is placed against it. This
ensures a good bond with the new earthfill and obtains the specified
moisture content and density at the contact of the inplace and new
earthfills.

**5. Control of moisture content**

During placement and compaction of earthfill and earth backfill, the
moisture content of the material being placed shall be maintained within
the specified range.

The fill material shall have a moisture content such that, when kneaded
in the hand, it will form a ball which does not readily separate which
struck sharply with a pencil, or which refuses to separate when pressed
between the hands.

The application of water to the earthfill material shall be accomplished
at the borrow areas insofar as practicable. Water may be applied by
sprinkling the material after placement on the earthfill, if necessary.
Uniform moisture distribution shall be obtained by disking.

Material that is too wet when deposited on the earthfill shall either be
removed or be dried to the specified moisture content prior to
compaction.

If the top surface of the preceding layer of compacted earthfill or a
foundation or abutment surface in the zone of contact with the earthfill
becomes too dry to permit suitable bond, it shall either be removed or
scarified and moistened by sprinkling to an acceptable moisture content
before placement of the next layer of earthfill.

**6. Compaction**

**Earthfill---** Each layer of fill will be compacted by two passes of a
standard tamping roller or equivalent method approved by the Engineer.
Tamping type roller shall consist of one or more cylindrical sections
having studs or feet projecting not less than 6 1/2 inches from the
surface of the drum. The number of tamping feet and the area of the feet
shall be such that the pressure on a single row of feet approximately
parallel to the axis of the drum is not less than 200 pounds per square
inch when supporting the full weight of the roller.

**Earth backfill---** Hand compacted fill, including fill compacted by
manually directed power tampers, shall be placed in layers not more than
four inches thick before compaction.

**7. Measurement and payment**

For items of work for which specific unit prices are established in the
contract, the volume of each type and compaction class of earthfill and
earth backfill within the specified zone boundaries and pay limits is
measured and computed to the nearest cubic yard by the method of average
cross-sectional end areas. Unless otherwise specified in section 10, no
deduction in volume is made for embedded items, such as, but not limited
to, conduits, inlet structures, outlet structures, embankment drains,
sand diaphragm and outlet, and their appurtenances.

The pay limits shall be as defined below, with the further provision
that earthfill required to fill voids resulting from overexcavation of
the foundation, outside the specified lines and grades, will be included
in the measurement for payment only under the following conditions:

• Where such overexcavation is directed by the engineer to remove
unsuitable material, and

• Where the unsuitable condition is not a result of the contractor\'s
improper construction operations as determined by the engineer.

Earthfill beyond the specified lines and grades to backfill excavation
required for compliance with OSHA requirements will be considered
subsidiary to the earthfill bid item(s).

***Method 1---***The pay limits shall be as designated on the drawings.

***Method 2---***The pay limits shall be the measured surface of the
foundation when approved for placement of the earthfill and the
specified neat lines of the earthfill surface.

***Method 3---***The pay limits shall be the measured surface of the
foundation when approved for placement of the earthfill and the measured
surface of the completed earthfill.

***Method 4---***The pay limits shall be the specified pay limits for
excavation and the specified neat lines of the earthfill surface.

***Method 5---***The pay limits shall be the specified pay limits for
excavation and the measured surface of the completed earthfill.

***Method 6---***Payment for each type and compaction class of earthfill
and earth backfill is made at the contract unit price for that type and
compaction class of earthfill. Such payment will constitute full
compensation for all labor, material, equipment, and all other items
necessary and incidental to the performance of the work.

***Method 7---***Payment for each type and compaction class of earthfill
and earth backfill is made at the contract unit price for that type and
compaction class of earthfill. Such payment will constitute full
compensation for all labor, material, equipment, and all other items
necessary and incidental to the performance of the work except
furnishing, transporting, and applying water to the foundation and
earthfill material. Water applied to the foundation and earthfill
material is measured and payment made as specified in Construction
Specification 8.

***All methods---***The following provisions apply to all methods of
measurement and payment. Compensation for any item of work described in
the contract, but not listed in the bid schedule is included in the
payment for the item of work to which it is made subsidiary. Such items
and the items to which they are made subsidiary are identified in
section 8 of this specification.

**8. Items of work and construction details**

Items of work to be performed in conformance with this specification and
the construction details therefor are:

[Bid Item 16, Bank Stabilization]{.underline}

(1) This item shall consist of the earthwork necessary to install the
    riprap and to fill and reshape the area as shown on the drawings.

(2) Earthfill material shall be from the required excavations and
    offsite sources designated by the Engineer as needed.

(3) The foundation area shall be stripped of all objectionable surface
    vegetation and debris and roughened as necessary in order to secure
    a good bond between the fill and the foundation area, except in
    areas where, in the opinion of the Engineer, a good bond is not
    required.

(4) Rock particles larger than 6 in. shall be removed prior to
    compaction.

(5) The maximum thickness of a layer before compaction shall be 8
    inches.

(6) Measurement and payment shall be by Method .