Pipe ramming is a technique for driving steel casings through various ground conditions, through the use of a powerful pneumatic hammer. This percussive energy drives the steel casing forward, allowing the trenchless installation of a new pipe underneath roadways, waterways, and railways.
How does pipe ramming work?
The reinforced open end of a pipe is placed into an excavation and aligned to its target destination (e.g., underneath a railroad). The other end is affixed to an extremely powerful pneumatic hammer, and through repeated percussion, the pipe is rammed through the soil by sheer force. As the casing is driven through, it “swallows” soil, rock, and boulders, and breaks through any obstructions.
Oversize boulders are cracked in their place and left in situ, by virtue of the cutting edge at the front of the pipe. Soil and debris are removed using augers and, in some cases, the pipe is left in place, and in other cases, any unsoiled pipe can be recycled once the casing has reached its terminus.
The advantages of pipe ramming
Pipe ramming removes virtually all risk of voids or settlement, especially in situations where soil conditions are tough or unknown. Pipe ramming is also utilized to install conductor barrels in directional drilling applications. Pipe ramming is advantageous in Type 3, Type 4, and unknown soil conditions where raveling or slippage of soil is a real risk, and where dewatering is not viable or practical. It allows subsurface construction and surface activities to continue uninterrupted, optimizing efficiency on and around busy roads or railways.
- Installation of 800 feet of 72” conductor barrel for a directional drilling project under the Athabasca River. The conductor barrel was telescoped in, 72” casing was installed for the first 200 ft and the soil cleaned out. Then 66” casing was installed at 400’ to terminus, and cleaned out. Then 200” of 72” casing was installed at the receiving end on the other side of the river. Conductor barrels were then cleaned out using 72” auger machine.
Trans Mountain Pipeline crossings of 42” casing. Project total of 20 crossings through Jasper National Park in 2008, and an overall project total of 3500 feet of 42” casing. Several crossings under the Trans-Canada Highway HWY 1, and railway crossings. Project began Sept 2008 and ended April 2009.