Crux provided core drilling and permeation grouting for the deep tunneled crossing alignment. As positional control of the borehole was paramount, optical survey tools were employed on a regular basis and directional drilling technologies were used to steer the borehole in the proper direction.
Crux core drilled and permeation grouted one 750-foot borehole for the south shaft, extending northward to the mid-point of the tunnel. The rock quality was generally good and Kinsel commenced tunneling. Crux then moved to the north shaft and began drilling southward. Poor rock quality and significant water infiltration were encountered between 200 and 600 feet. Kinsel authorized additional coring and grout coverage in this zone. Crux employed directional drilling technology to treat the specific zone without unnecessary drilling in more competent portions of the alignment. This reduced the overall time and cost required to complete the project.