Drilled Shafts in Difficult Access and Sensitive Environments
At the Bryson City, NC 69 KV transmission line project, our experience and innovation enabled us to overcome the
challenges associated with steep terrain, low headroom, and large equipment in a largely inaccessible space, to
safely construct nine drilled shafts through some of the hardest rock that a driller can encounter. Logistics included
dismantling equipment such as large cranes to transport them up the narrow dirt roads in the hollow to the jobsite.
Shaft ID #14. Above, AD150 rig installing
8-foot-diameter drilled shaft with 26.5 feet
of rock removal. McKinney is accustomed
to using track drills like this one to access
tight locations for installation just as reliable
as that in open access. Left, after placement
of 130 feet tall Valmont Utility Pole.
Shaft ID #23. Above, LLDH rig
installing an 8-foot-diameter drilled
shaft with 32 feet of rock removal.
Right, after placement of 130-foot-tall
Valmont Utility Pole.
Shaft ID #19. An 8-foot-diameter drilled shaft with 25.5 feet of rock removal.
Shaft complete and site restored, ready for pole setting. McKinney employed
special water pumping methods to protect the adjacent stream from silt runoff.
Shaft ID #15. McKinney placing the 4.5-ton rebar cage for this 8.5-footdiameter drilled shaft with 10 feet of rock removal. Note the drilling rig
set up in the background at Shaft ID #14.
Shaft ID #23. Access to the shaft involved the traversing of 30 percent
grades using tracked equipment on narrow dirt roads over a distance of
1/4 of a mile.
Shaft ID #41. Drilling an 8.5-foot-diameter shaft using a special low
headroom boom, below active utility lines. Boom height: 25 feet.
Drilling Depth: up to 45 feet.
Shaft ID #17. Coring at Shaft #17. Granite gneiss is some hard rock
for sure, but not too hard for McKinney!
W W W. M C K I N N E Y D R I L L I N G . C O M