Traversing Surveying for Engineers ERE 371

1
TraversingSurveying for EngineersERE 371
2
Traversing

• Definition of traverse
• Series of connected lines
• Components of traverse

3
Traversing

• Definition of traversing
• Application

4
Types of Traverses

• Mathematical Closure
• Closed traverses
• Geometrically closed (polygon)

5
Closed Traverse Geometrically Closed
E
D
Control station
G
Traverse station
F
C
H
A
B
6
Types of Traverses

• Closed traverses cont.
• Geometrically open

7
Closed Traverse Geometrically Open
Control station
Traverse station
E
D
F
G
B
C
H
A
8
Types of Traverses (contd)

• Open traverse

9
Open Traverse
Control station
Traverse station
E
D
F
G
B
C
H
A
10
Measuring and Expressing Angles

• Interior angles

11
Measuring and Expressing Angles

• Deflection angles
• Measured left or right from extended line to next
  line
• Often used for geometrically open traverses (e.g.
  along route)
• Procedure

12
Measuring and Expressing Angles

• Angles to right
• Traversing by azimuths

13
Measuring and Expressing Distance

• Use any method to meet required accuracy
• Approach

14
Stationing

• Application
• Use stations and pluses

15
Stationing
16
Traverse Stations (Hubs)

• Location depends on purpose of subsequent survey
• General issues
• Issues with location

17
Referencing Traverse Stations

• Measure ties
• Issues

18
Good Distribution of Tie-Ins
5.13 m
7.85 m
4.52 m
Building
19
Poor Distribution of Tie-Ins
5.13 m
4.52 m
Building
5.24 m
20
Errors and Mistakes

• Personal errors
• Instrumental errors
• Natural errors
• Mistakes

21
Traverse Computations

• Purpose
• Check if traverse meets required
  accuracy/precision
• Adjust traverse to get geometric consistency
• Compute locations of control points
• Components of compass rule adjustment
• Adjust angles (satisfy geometry)
• Determine preliminary line directions
• Calculate departures and latitudes
• Adjust departures and latitudes
• Calculate station coordinates
• Calculate adjusted lengths and directions of lines

22
Readings

• Chapter 9 sections 9.1 9.8, 9.10, 9.11