Leica FlexLine plus User Manual page 105

Horizontal and
vertical geometry
elements combined

FlexLine plus, Programs
Element Description
Quadratic A quadratic parabola has the advantage that the rate of change of grade
parabola is constant, resulting in a "smoother" curve. A quadratic parabola has to
be defined by:
• Start chainage and start height of P1.
• End chainage and end height of P2.
• Parameter, or Length (L), grade of entry straight (Grade In) and grade
of exit straight (Grade Out).
+%
P1
TSOX_114
TSOX_115
b2
b1
-%
a2
R1
a1
TSOX_116
a = Horizontal alignment (top view)
R1 Radius 1
R2 Radius 2
a1 Straight
a2 Curve with R1
a3 Partial spiral with R1 and R2
a4 Curve with R2
a5 Spiral out with R2 and R=
a6 Straight
Start and end chainage and tangent points can be different for the horizontal and
vertical alignments.
-%
P2
L
L
P1
+%
-%
a b
b4
b3
+%
a4
a3
R2
b = Vertical alignment (front view)
b1 Straight
b2 Curve
b3 Straight
b4 Parabola
b5 Straight
∞
• Tangent point
P1 Start point
P2 End point
P2
L Length
% Slope
b5
-%
a5
R
a6
105