Page 400 - Trenchless Technology Piping Installation and Inspection

350 Cha pte r Ei g h t

Verify steel pipe is new with smooth interior and exterior surfaces, is used within the
entire influence area of the roadbed, has clean and square ends, joints are watertight,
defective pipe is not used, and damaged pipe is removed.

Verify HDPE pipe is supported and secured reasonably with rollers, skates or other
protective devices to prevent damage to the pipe, is new with smooth interior and
exterior surfaces, is used within the entire influence area of the roadbed, has clean and
square ends, joints are butt-fused and watertight, pipe with gouges exceeding 10
percent of the pipe wall thickness or kinked sections is not used, and damaged pipe is
removed.
Verify the pullback rate does not exceed 10 ft/min to avoid heaving.

Verify drilling fluid departs entry and exit drilling points only, and that drilling fluid
in the exterior annular region of installed pipe is not removed after installation.

Verify any unsuccessful drill hole is back-filled immediately.
Verify each end of the pipe is sealed with a cap, restoration is completed, and attach
Inspector’s Daily Report (IDR), form 2228.

Permit No. __________________________
Inspector: ___________________________
Date: _______________________________

FIGURE 8.23 Sample checklist for inspection of horizontal directional drilling
operations. (Continued)

the size of the replaced pipe. The product originally transported by
the replaced pipe can be temporarily rerouted (bypassed) to prevent
overflows and provide uninterrupted service.

Pipe Bursting
In most of pipe-bursting operations, the new pipe is pulled into place.
The rear of the bursting head is connected to the new pipe, and the front
end of the bursting head to either a winching cable or a pulling rod
assembly. The bursting head and the new pipe are launched from the
insertion pit. The cable or rod assembly is pulled from the pulling or
reception pit. Pipe bursting may use static, pneumatic, or hydraulic
method of bursting the existing and host pipe. Pipe bursting must fol-
low conditions set in this document. Figure 8.24 illustrates the pipe-
bursting process.
8.7.2 Materials

Pipe
Pipe used in this method includes an existing host pipe and a replace-
ment pipe.