The tunnel template is defined from a polyline. The polyline may be open or closed and, may be generated either clockwise or counter-clockwise. Once selected (you are asked to Select Tunnel Template) the following data is requested:
Name: Name of the cross-section. S1 is shown by default. If more than one cross-section is created, they will be named S2, S3, etc.
Horizontal distance form H.a. to Center:A positive value indicates that the ground plan alignment is to the right of the cross-section’s center and a negative value indicates it is to the left. Differently to the grade line and superelevation application point, the ground plan application point can be defined to be outside the tunnel template.
Vertical distance from Keystone to V.a.:A positive value should be indicated if the keystone point is above the grade line and superelevation application point and negative otherwise. Under normal conditions, this value should always be positive. The grade line and superelevation application point should be within the tunnel template.
Horizontal distance from V.a. to H.a.:In this case the reference is the ground plan alignment’s application point. One will therefore have to indicate a positive value if the vertical alignment and superelevation application point is to the right of the alignment and a negative value if it is to the left.
Advanced (Superelevations): If a superelevation file has been selected, the program allows tilt the tunnel template depend on the superelevation values. If Keep tunnel template fixed is selected and the tunnel template is open, the superelevations will be applied, creating the roadbed and closing the tunnel template.
