D. EXCAVATION NEAR EXISTING STRUCTURES:
1.
Attention is directed to the fact that there are pipes, manholes, drains, and
other utilities in certain locations. An attempt has been made to locate all
utilities on the drawings, but the completeness or accuracy of the given
information is not guaranteed.
As the excavation approaches pipes, conduits, or other underground structures,
digging by machinery shall be discontinued and excavation shall be done by
means of hand tools, as required. Such manual excavation, when incidental to
normal excavation, shall be included in the work to be done under items
involving normal excavation.
Where determination of the exact location of a pipe or other underground
structure is necessary for properly performing the work, the Contractor shall
excavate test pits to determine the locations.
3.03 BACKFILL PLACEMENT AND COMPACTION:
A. GENERAL:
l.
2.
Prior to backfilling, the Contractor shall compact the exposed natural sub-
grade to the densities as specified herein.
After approval of sub-grade by the Engineer, the Contractor shall backfill areas
to required contours and elevations with specified materials.
The Contractor shall place and compact materials to the specified density in
continuous horizontal layers. The degree of compaction shall be based on
maximum dry density as determined by ASTM Test D 1557, Method C. The
minimum degree of compaction for fill placed shall be as follows:
Percent of
Location Maximum Density
Below pipe centerline 95
Above pipe centerline 92
Below pavement (upper 3 ft.) 95
Embankments 95
Below pipe in embankments 95
Adjacent to structures, 92
Below structures 95
The Engineer reserves the right to test backfill for conformance to the
specifications and Contractor shall assist as required to obtain the information.
Compaction testing will be performed by the Engineer or by an inspection
laboratory designated by the Engineer, engaged and paid for by the Contractor.
If test results indicate work does not conform to specification requirements, the
Contractor shall remove or correct the defective Work by re-compacting where
appropriate or replacing as necessary and approved by the Engineer, to bring
the work into compliance, at no additional cost to the Owner. All backfilled
materials under structures and buildings shall be field tested for compliance
with the requirements of this specification.
Where horizontal layers meet a rising slope, the Contractor shall key each layer
2019 CIPP Lining Project Earthwork
Nashua, NH
02300-6
