Understanding when and how to use pipe ramming (Part 5 in a series)
This is the fifth blog in a series about trenchless technology, a rapidly growing sector in construction and civil engineering that requires few trenches or no continuous trenches at all. If you have not been following the last few blogs, you can give yourself some background by following links below.
Pipe ramming is a trenchless technique for installation of pipes or casings for different applications. In pipe ramming, a pneumatic tool is used to hammer the pipe or the casing into the ground while the soil that was excavated from creating the hole is removed to the surface. This technique is commonly used under highway and rail embankments. It is generally not steerable.
Pipe ramming is an ideal solution for low-risk tunneling operations. Typically used to install steel sleeve pipes and casing ducts through embankments or loose ground, pipe ramming is extremely versatile. Because it doesn’t require a thrust wall—or a wall to push against while driving in pipe segments—pipe ramming can operate from a pit or above ground level. Pipe ramming is also a fast solution and, in many cases, has lower overall costs.
Typical applications include using steel pipes from 150 to 1,600 millimeters for drainage culverts or to accommodate multiple services under roads, rivers, airport runways, buildings, and contaminated landfill sites. These crossings can be for water, oil, gas, electricity, sewerage, or communication.
The advantages of pipe ramming include:
- Enables large-diameter pipes to be installed at shallow depths.
- No risk of ground settlement as steel pipe is installed before excavation.
- Fast setup time and can be used at steep angles.
- Pipe ramming is one of the very few trenchless methods where a shutdown may not affect the resumption of the drive. The drive can normally be restarted after substantial down time.
But, like all trenchless technologies, pipe ramming is not suited to every project. One of the drawbacks of this technology is the loud noise it generates, which requires mitigations and monitoring in urban areas. Also, there is typically no alignment control, smaller diameter pipes are hard to clean out, and dewatering will be required if your tunnel alignment is below water table.
Compared to other trenchless methods, such as auger boring and directional drilling, pipe ramming can save both total installation time and costs when it is used under favorable conditions. Installation time can often be much shorter than in auger boring because the width and depth of pits required in pipe ramming are smaller, making the actual installation faster. While directional drilling is generally better suited for long bores, pipe ramming is often superior for installations of simple and straight drives in the range of 5 to 60 feet. Pipe ramming is one of the best approaches and generally would not result in ground loss since the soils inside the pipe is not excavated until the entire casing is installed in place.
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