Class Objectives - University of Idaho notes/class 21 locating...Class Objectives •Identify route...
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Transcript of Class Objectives - University of Idaho notes/class 21 locating...Class Objectives •Identify route...
10/19/2011
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CE 211 – SURVEYING ENGINEERING CLASS 21: ROUTE SURVEYING
Ahmed Abdel-Rahim, Ph.D, P.E.
Associate Professor, Civil Engineering
Class Objectives
• Identify route surveying objectives and procedures
• Define horizontal curves parameters and equations
• Define degrees of curvatures for horizontal curves using arc and chord definitions
• Relate R, D, Δ, L, LC, T, E, and M for a horizontal curve
• Restation horizontal curves
LOCATING A CURVE
• Deflection Angles
• Deflection angles and incremental chords
• Deflection angles and total chords
• Coordinates
• Offsets
LOCATING A CURVE
• Except for a very sharp circular curve (i.e., with a small radius), it is not practical to lay out the curve by simply swinging an arc from its center.
– One method for field location of a curve involves measurement of the deflection angles between the tangent and the points along the curve and measurement of the chord lengths between those points.
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LOCATING A CURVE
LOCATING A CURVE
• Deflection Angles and Chords
– Deflection Angles
– Chord Lengths
– Field Procedure
• Orientation on the Curve
– To Orient to the Curve
– When Oriented to the Curve
– When the PI Is Inaccessible
LOCATING A CURVE
The deflection angle to any point on the curve is equal to the sum of the incremental deflection angles for each previous subdivision of the arc.
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LOCATING A CURVE
FIGURE 10-9. The length of a chord is equal to twice the radius times the sine of the chord’s deflection angle.
LOCATING A CURVE
Beginning of a curve layout procedure.
LOCATING A CURVE LOCATING A CURVE
Table 10-1. Deflection Angle Calculations
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LOCATING A CURVE
Illustration for Example 10-8.
LOCATING A CURVE
Field notes for staking out a horizontal curve .
LOCATING A CURVE
Orientation on the curve.
LOCATING A CURVE- PI is Inacessiblae
When the PI is inaccessible, random points A and B are set on the tangents so that the PC and PT can be located with reference to them.
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COMPOUND AND REVERSE CURVES
Different kinds of horizontal curves.
COMPOUND AND REVERSE CURVES
Nomenclature for the compound curve.
COMPOUND AND REVERSE CURVES
To orient to the point of compound curvature.
COMPOUND AND REVERSE CURVES
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HW assignment
• Chapter 10
– 1, 3, 5, 9, 11, 13, 17, 19
– Due Fri 10/21/10
