Calculating the East portal entry skew for the Mitchell Point Tunnel using TPC. Solved by creating tunnel alignment and two tunnel templates, one just outside the entry wall and one inside. Then pair corresponding points from each template. Stake these pairs using a reference line function to a point on the rock face having a value zero offset, repeat, and connect dots with painted neat line for material removal.
– Gregory Spurlock
Statewide Land Surveying, Inc.