HomeMy WebLinkAbout15110.pdf BICKFORD OF CARMEL, IN 12/12/2012
EXCAVATION AND BACKFILLING 15110-1
SECTION 15110
EXCAVATION AND BACKFILLING
PART 1 - GENERAL
1.1 RELATED DOCUMENTS
A. Drawings and general provisions of Contract, including General and Supplementary Conditions
and Division-1 Specification sections, apply to work of this section.
1.2 SUMMARY
A. Perform excavations to depths indicated on the Drawings or as required for installation. During
excavation, pile material suitable for backfilling, in an orderly manner, a sufficient distance from
the banks of the excavation to avoid over-loading and to prevent slides or cave-ins. Remove and
waste excavated material not required or suitable for backfill as directed by the
Architect/Engineer. Keep excavated material trimmed so is causes the least inconvenience
possible to the public and adjoining property owners. At street crossings, sidewalks, and other
points where the Architect/Engineer deems necessary, bridge trenches in a secure manner,
preventing serious interruption of travel and providing access to fire hydrants and public and
private premises.
1.3 EXISTING CONDITIONS
A. Verify the existence and location of underground utilities along the route of work. Omission from,
or inclusion of, utility locations on the Drawings is not to be construed as the nonexistence of, or a
definite location of, existing underground utilities.
B. Protect existing conditions/utilities from damage due to the operations of the Mechanical
Contractor. Any damage to utilities or existing conditions shall be repaired at no cost to the
Owner.
C. Move minor structures and restore temporary openings in fences to their original condition.
Stockpile any culverts, pipes, cables, or minor structures which are moved and reset in the
original locations. For construction purposes, determine the actual condition of structures and
miscellaneous obstacles to move. Removal and placement of these items shall be considered as
part of the Contractor's obligation, and no additional payment shall be made.
1.4 REQUIREMENTS OF REGULATORY AGENCIES
A. American Association of Transportation Officials (AASTO)
B. Associated General Contractors (AGC)
C. Occupational Safety and Health Administration (OSHA)
1.5 TESTING
A. Perform compaction testing of backfill materials as directed by the Architect/Engineer.
1.6 SUBMITTALS
A. Submit for approval testing reports, conducted by an independent testing laboratory, to verify
backfill compaction meets Contract requirements.
PART 2 - PRODUCTS: Not Applicable
BICKFORD OF CARMEL, IN 12/12/2012
EXCAVATION AND BACKFILLING 15110-2
PART 3 - EXECUTION
3.1 EXCAVATION
A. Excavate by open cut except that short sections of a trench may be tunneled if, in the opinion of
the Architect/Engineer, pipe can be properly installed and backfilled properly in such tunnel
sections. Excavate the necessary width for the proper laying of the pipe with banks sloped in
accordance with OSHA standards. Provide separate excavations for sewer, and water lines
respectively, with a minimum of 3 feet of undisturbed earth between each. In locations, such as
close to buildings, where separate excavations for sewer and water lines are impractical, lay
water pipe on a solid shelf at least 18 inches above the top of sewer.
B. Excavations for sewers shall have a clear space between the barrel of the pipe and excavation
wall not exceeding 8 inches on either side of pipe. The width of the excavation above the top of
the pipe may be as wide as necessary for soil conditions, sheeting, bracing, and proper
performance of the Work.
C. Implement earth retention systems as appropriate for the excavation depths required and soil
types encountered in accordance with OSHA standards to protect workmen and adjacent
structures. Do not remove earth retention systems until the excavation is backfilled sufficiently to
protect the pipe and prevent injurious caving.
D. Control grading in the vicinity of excavations to prevent surface water from flowing into open
excavations If water enters the excavation, remove and dispose of the water until utility lines,
fittings, manholes, and other appurtenances are in place and sealed against the entrance of
water. Water, earth, or foreign materials shall not be permitted to enter the utility lines.
E. Keep excavations free from water during construction. Do not lay pipe or appurtenances in
water. Pump or dewater as required to permit the proper jointing of pipes. Convey the discharge
from dewatering operations to drains or natural drainage channels.
F. Perform final grading of excavation bottoms with hand tools; carry machine excavation only to the
depth that soil bearing for pipes is not disturbed. Grade the bottom of evenly to ensure uniform
bearing for all pipes. Cut holes as necessary for joints and joint-making. As an alternate method,
over excavate to at least 4 inches below required bottom levels and refill to proper grade with
sand or gravel firmly compacted.
1. In Rock, Cemented Gravel, Old Masonry, or Other Hard Material, excavate to at least 4
inches, or as directed by the independent testing agency, below the pipe at all points and
refill to grade with sand or gravel firmly compacted.
2. In Fill Containing Refuse, Organic Matter, or Similar Substances, remove such material to a
depth at least 6 inches, or as directed by the independent testing agency, below the pipe at
all points and refill to grade with sand or gravel firmly compacted.
3.2 BACKFILLING
A. Backfill excavations only after piping is inspected and tested and the locations of pipe lines and
appurtenances are recorded. For a depth of at least three pipe diameters above the top of the
pipe, backfill by hand with earth or granular material free from large stones, rock fragments, roots,
and sod; compact backfill thoroughly in layers not exceeding 4 inches in thickness, taking care
not to disturb the pipe or injure pipe coating.
B. For the remaining depth, backfill with materials as specified in the preceding paragraph, except
that material may contain stones, rocks, concrete, or masonry materials (but no cinders) with a
maximum dimension of 2 inches, providing the voids in such coarse material are completely filled
BICKFORD OF CARMEL, IN 12/12/2012
EXCAVATION AND BACKFILLING 15110-3
with earth or granular material. In the event that sufficient suitable material specified for trench
backfill is not available supply and place the requisite additional material without an increase in
the Contract Price. Thoroughly compact backfill with equipment appropriate to the application, in
lifts appropriate to the method selected. Regardless of the compaction method lifts shall not
exceed 8 inches, measured loose.
C. Compact backfill in areas requiring structural fill such as paved roads, parking areas and other
structures to a density of at least 98 percent of the maximum dry density as determined by ASTM
D 698 unless permitted otherwise under the Division 2 Specifications. In locations where backfill
will be nonstructural such as grassy areas and sidewalks, compact to a minimum of 90 percent of
the maximum dry density as determined by ASTM D 698 unless permitted otherwise under the
Division 2 Specifications. Backfill material shall have moisture content in the range of three
percent above to three percent below optimum moisture at the time it is placed.
D. Backfill excavations through specially treated surface, or other existing surfaced areas, and
replace to the original grade with surfacing material, of equal type, to the same depths and limits
as the material removed.
E. Re-excavate and re-compact improperly filled excavations where settlement occurs to a depth
where proper compaction can be measured, then refill, re-compact and restore the surface to the
required grade and compaction at no additional cost to the Owner.
3.3 TESTING
A. The testing laboratory will take the following number of tests required to determine the specified
compaction. Fill not meeting the required compaction, as determined by the testing laboratory,
shall be removed, replaced, re-compacted, and retested at the expense of the Contractor. The
location of each test shall be recorded and submitted with the testing laboratory results.
1. Fill, Non-structural. One test per 1,000 square yards per 8-inch lift.
2. Backfill Adjacent to Buildings, either Structural or Non-structural One test per 50 linear feet
per 8-inch lift.
3. Structural Fill. Testing and inspection shall be on a full time basis when placement of fill is in
operation.
4. Utility Trench Backfill, Non-structural One test per 200 linear feet per 8-inch lift.
5. Utility Trench Backfill, Structural. One test per 100 linear feet per 8-inch lift.
END OF SECTION