- LocationTrois-Rivieres, QC
MethodsHorizontal Directional Drilling, Pilot Hole Intersect
Michels used pilot hole intersect technology to install 2,273 metres of 20-inch steel pipe through solid rock under the St. Lawrence Seaway. Because the elevation of bedrock was fairly deep on the north side of the crossing, a telescoping method was used to drill 122 metres of 42-inch, 36-inch and 20-inch steel casing was driven down through the overburden soils to the bedrock.Michels used its 840,000-pound drill rig set up on the north side to drill 1,487 linear metres and its 1.2 million-pound drill rig on the south side to drill 1,029 linear metres to intersect with it. The drill was conducted through limestone and shale bedrock ranging in strength from 3,000 psi to 8,000 psi. Overburden consisted of fine sand, clay and traces of gravel. Because the crossing was performed during winter months when temperatures reached -42 degrees celsius, tents were erected on both sides for protection from the elements. Noise barriers were secured to the inside bracing of the north-side tent to keep noise below the acceptable decibel barriers.