Page 408 - Trenchless Technology Piping Installation and Inspection

358 Cha pte r Ei g h t

4. Protection:
• Traffic barriers must be installed adjacent to shaft loca-
tions according to the state DOT or an agency having
jurisdiction or according to the standard specifications for
construction. Temporary beam guardrail must also be
installed according to the current DOT or agency having
jurisdiction or construction specifications.
• Fencing barriers must be installed adjacent to shafts, open
excavations, equipment and supplies with suitable fenc-
ing and plastic drums to prohibit pedestrian access to the
work site. Equipment must not be used as fencing to pro-
tect shafts and pits.
• The contractor must construct and operate safe access
shafts and pits according to OSHA guidelines and/or all
applicable regulatory requirements.

8.9 Settlement/Heaving Monitoring

1. This method must be performed in a manner that will min-
imize the movement of the ground in front of, above, and
surrounding the boring operation, and will minimize
subsidence of the surface above and in the vicinity of the
boring.
2. Potential settlement must be monitored at each edge of right-
of-way, each shoulder point, each edge of pavement, the edge
of each lane (or centerline for two lane roads), and otherwise
at 50-ft intervals along the pipe centerline.
3. A survey must be performed 1 day prior to initiating this
operation at each required monitoring location. A similar sur-
vey must then be performed at each location, on a daily basis,
until the permitted activity has received a final inspection.
This survey establishes the preexisting and postconstruction
conditions, and the amount of settlement. All survey read-
ings must be recorded to the nearest one-hundredth (0.01) of
a foot. Whenever possible, trenchless pipe installations must
not be installed directly under a pavement crack. Digital pho-
tographs of the pavement conditions must also be taken prior
and after the pipe installation.
4. All operations must stop immediately whenever monitored
points indicate a vertical change in elevation of 1 in. or more,
or any surface disruption is observed. The contractor must
then immediately report the amount of settlement to the
engineer/inspector.