What Does Slurry Microtunneling Mean?
Slurry microtunneling is a microtunneling process that utilizes a slurry mechanism for excavating the borehole. The slurry helps in lubricating as well as removing the excavated cuttings from the borehole. The slurry microtunneling system comprises several components, including:
- Microtunnel boring machine (MTBM)
- Jacking frame
- Slurry lines
- Slurry separation plant
- Guidance system
Microtunneling is a trenchless tunneling technique used to create small tunnels. The excavation is done using the MTBM and creates tunnels up to 1.8 meters (6 feet) in diameter. This method is used to install pipelines beneath existing structures or natural barriers.
Trenchlesspedia Explains Slurry Microtunneling
Slurry microtunneling is used for installing gravity flow pipelines where tight line and grade tolerances are required. These machines can independently counterbalance earth and hydrostatic pressures and are ideal for small diameter, unmanned tunneling projects. An MTBM requires a jacking and reception shaft and usually has a maximum drive length of 305 meters (1,000 feet). Extended drive lengths are possible by using enhanced guided systems, additional slurry pumps and intermediate jacking stations (IJS).
The process provides continuous support to the excavation face by applying fluid pressure or mechanical pressure to balance the earth and groundwater pressures. Microtunneling is an efficient method, as it is environmentally friendly and accurate to line and grade. It also does not require dewatering, even while working below the water table — with the exception of the launch and reception shafts.