Technology: Pipe Ramming and its uses in road construction projects.
Pipe ramming (pipe hammering or pipe jacking) utilizes pneumatic percussive blows to drive pipe through and into the ground with a pneumatic hammer.
Pipe ramming can be generally described as follows:
First, a starting point and end point are identified and marked, and a shaft or a pit (launch pit, entry pit, drive pit, or drive shaft) is constructed at the starting point. Next, a steel leading-edge band for reinforcement is attached to the leading edge of the front casing. The front casing is then placed in the drive pit, supported by adjustable bearing stands, launch cradles and platform, I-beams, or pipe jacking/auger boring machine tracks, and adjusted to achieve the desired line and grade. The pneumatic hammer or pipe ram device is then attached using collets (or special adapters) to the pipe or casing, and connected to a pneumatic or hydraulic power source, such as an air compressor. Ramming cones can be used with larger pipes to increase the amount of energy transferred between the pneumatic hammer and the pipe. Finally, the driving begins, and continues until the pipe reaches the exit point (exit pit or reception pit). If additional segments of pipe are required, then after each segment is installed, the hammer is removed and additional segments are welded to the last installed pipe. After the full length of the pipe is installed, the casing is cleaned out, the equipment is removed, and the area is restored.
Typically, pipe ramming is used for shallow and/or short installations,
such as under roads and railroads. This method is generally more suitable for
preventing heave and settlement of the ground surface than other trenchless
technologies. In addition, pipe ramming equipment is typically more versatile
as it can operate in tight spaces and often weighs much less than auger boring
or directional drilling equipment. Pipe ramming is well suited for projects
with relatively short runs in soils with loose rock, or extremely fine sands.
This is one of the benefits of a pipe ramming as such soils might frustrate
augers or drilling heads used in the other trenchless technologies.
Early engagement of a licensed attorney is recommended if
changed conditions are encountered during the performance of pipe ramming.