Page 54 - Trenchless Technology Piping Installation and Inspection

New Pipeline Installations 27

RAM
Air hose Soil removal Pipe
adapter
Pressure plate or
pressure hooks Tapered locking Weld-on
ram cone eye pads

Webbed Bearing stand
ratcheting assembly
FIGURE 1.22 Pipe ramming. (Source: TT Technologies, Inc.)

rammed pipe to supply water, bentonite, and/or other drilling lubri-
cants to facilitate spoil removal and reduce friction. Special adapters
connect pipe of different sizes to the ramming tool. After the adapters
are in place, the ramming tool is connected with lugs welded to the
pipe. These lugs are used to hold straps, chains, or hoists linked to the
ramming tool. After each section of the pipe is rammed, another seg-
ment is welded or joined by interlocking and the procedure is repeated
until the whole length of the pipe is completed. After the completion
of ramming, cleaning out of the pipe can be done by a variety of
methods, including a pipe cleaning pig or plug and high-pressure air,
or auguring.
The size of bore pit required for pipe ramming (PR) and the
lengths of the rammed pipes are dependent on project conditions. If
sufficient space is available, the bore pit is constructed to enable the
pipe to be driven in longer sections. In the case where the area is con-
gested, the pipe is driven in smaller sections, which requires more
time for welding these smaller sections.
For situations where the line and grade are not critical, the pipe in
the pit can be supported by suspension from construction equipment
such as backhoes, cranes, and side-boom tractors; by concrete, wood,
or block supports; or directly on the pit floor. In cases where the line
and grade are critical, the pipe is supported by adjustable bearing
stands, launch cradles or platforms, I-beams, and auger boring
machine tracks.
ASCE Manuals and Reports on Engineering Practice No. 115 on Pipe
Ramming Projects (ASCE, 2008), provides complete information on the
pipe-ramming technique. The following sections describe new pipe
ramming innovations:

Using Pipe Ramming in HDD Projects Bore (product pipe) salvage: A
pneumatic pipe rammer may effectively be used to salvage a stuck