CommScope ConQuest Conduit Construction - Manual (Page 23)

Underground Installation Methods 4.5
Open Trench - Backfilling
Open Trench Backfilling Method
It is best to place the softest soil directly on and around the conduit. DO NOT place large rocks directly on
the conduit. Allow at least 2 – 4 inches (5 - 10 cm) of dirt to cushion the conduit.
Best practice to insure long-term protection of underground facilities is to
utilize sand for padding the conduit. Sand provides a more stable environment
for the conduit prohibiting damage from rocks and allowing water to drain
away easily. Sand also provides protection during future excavation near your
facilities. A change in soil condition provides warning that there is a utility
present. Sand alone should not replace the practice of placing warning tape,
but rather should serve as a supplemental protection practice.
Place warning tape in the back-fill process. Fill the trench and compact as
required. Tamp the trench to provide compaction that will prevent the trench
from ‘sinking’ later.
Conduit organizers should be used when placing multiple
conduits in a trench. Organizers prevent the conduits
from twisting over and around each other, by keeping the
conduits in alignment, cable pulling tensions are reduced.
Finally, when water is present in the trench or when using
an extremely wet concrete slurry, floating of the conduit
can be restricted through the use of conduit organizers.
TECH TIP
Backfilling in lifts
of about six inches,
compacting each
lift before starting
the next, will help
prevent the trench
from sinking.
2”
larger rocks
permissible
3” to 4”
1½” or
smaller
rock