Construction Specification 423 – Earthfill and Gravel Fill
The work consists of the construction of earth embankments, other earthfills, earth
backfills, and gravel fills required by the drawings and specifications.
All fill material shall be obtained from required excavations and approved 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.
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.
Gravel fill is composed of sand, gravel, crushed stone or mixtures thereof. They shall
be selected as necessary to avoid the inclusion of organic matter, clay balls, excessive
fine particles or other substances that would interfere with their free-draining properties.
Unless specified in the plans, the material shall be well graded with 3-inch maximum
size, no more than 50 percent by weight finer than the #4 sieve and no more than 5
percent by weight finer than the #200 sieve.
The types of material used in the various fills shall be specified as one of the types
described above or as described on the drawings.
3. Foundation preparation
Foundations for earthfill and gravel fill shall be stripped to remove vegetation and other
unsuitable material or shall be excavated as specified. All stumps and roots having a
diameter of one inch or larger shall be grubbed out to a depth of at least two feet below
subgrade elevation for concrete s