SH2 Muldoon’s Corner upgrade – Opus (Oct/Nov 2007)
Muldoon’s Corner is a difficult section of State Highway 2 which needed realignment. It is located
near the summit of the narrow and winding Rimutaka Hill Rd and features tight corners, no shoulder
and near vertical faces above and below the road. It is also frequently closed due to extreme wind
conditions, making work on site difficult.
Project scope
As part of the planned realignment design our client, Opus International Consultants, needed
information from several cored boreholes to be drilled in the middle of the traffic lane. Further
holes were required below the road at the base of some of the retaining walls and also on the spurs
immediately above the road.
Complicating factors and solutions
The bore holes on the road required that SH2 to be reduced to one lane each day and the rig moved
onto the hole in the morning to work before moving off in the afternoon to allow the lane to be
reopened in time for peak traffic flows.
At the same time a number of other holes were drilled across the site by our light weight rig,
which was craned into position onto platforms below the road to carry out a programme of cored
boreholes. During this time Griffiths Drilling were also carrying out trial pit investigations by
excavator and providing multiple lane closures to allow the client to conduct such things as
mapping of rock faces along the road and seismic surveys.
Helicopter access
The programme culminated with the boreholes drilled on the spurs above the road. For this stage a
drilling rig was carried into place by helicopter as the only access to site is by foot and using
ladders. These holes were also the deepest on the project.
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