care shall be taken to provide recesses in the bedding or trench bottom, as
required, to relieve each bell of any load.
Placement of trench bedding shall be performed by skilled personnel and shall
precede the laying of pipe by a reasonable distance.
From the top of the bedding to a minimum of 6 inches above the pipe crown,
the trench shall be backfilled with the specified material placed evenly on both
sides of the pipe with care being taken not to raise or otherwise dislodge the
pipe. Backfill to this depth shall be thoroughly compacted with approved
hand-operated devices.
No stone or rock fragment greater than 1 inch shall be placed into the trench
nor shall large masses of backfilling material be dropped into the tamped
layers of backfill until a minimum of 6 inches of backfill has been placed over
the top of the pipe.
Wet backfill shall not be placed in the trench or compacted. CONTRACTOR
shall suspend compacting activities until the backfill materials exhibit a
moisture content sufficient to allow for proper compaction.
3.9 DRAINAGE SAND
A.
B.
The Drainage Sand shall be installed as shown on the Drawings.
No Drainage Sand shall be placed until the CQA Consultant has approved the
installation of the underlying geosynthetics.
Drainage Sand over drainage geocomposite shall only occur under the
observation of the CQA Consultant.
CONTRACTOR shall use extreme care in placing Drainage Sand over the
geosynthetics. The Drainage Sand shall be placed in a manner that will
maintain a minimum thickness of 12 inches of material at all times between
the geosynthetics and the bottom of construction equipment spreading
material. Unless otherwise specified by ENGINEER, all equipment operating on
earthen materials overlying the geosynthetics shall comply with the following.
Allowable Equipment Thickness of Overlying
Ground Pressure (psi) Compacted Soil (ft)
<5 1.0
<10 1.5
<20 2.0
>20 3.0
CONTRACTOR shall control grades using a method which will not damage the
geosynthetics. Grade stakes shall not be used in areas where geosynthetics
File No. 3066.09 Earthwork 02200 - 11 of 14 December 2017
