Page 52 - Trenchless Technology Piping Installation and Inspection
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New Pipeline Installations 25
FIGURE 1.19 PTMT operation, step 1: Installation of pilot tube. (Source:
Bohrtec, 2008.)
FIGURE 1.20 PTMT operation, step 2: Insert auger casing. (Source: Bohrtec,
2008.)
FIGURE 1.21 PTMT operation, step 3: Replace auger casing with product
pipe. (Source: Bohrtec, 2008.)
In step 2, the pilot tubes at the drive shaft are connected to a
reamer with a diameter slightly larger than the diameter of the prod-
uct pipe. Following the reamer is the auger casing, which helps in
transporting the spoil back to the shaft. The spoil is then removed by
a muck bucket or a vacuum truck, depending on the soil type. Step 2
is complete when the reamer and the auger reach the reception shaft.
This operation is shown in Fig. 1.20.
