Curve Ranging

Curve Ranging CONTENT

No.

Title

Page

1

Objective

2

2

Introduction

2

3

Equipments and Apparatus

3-4

4

Procedure

4-5

5

Data analysis

6-7

i) ii) 6

Discussion

7

Conclusion

8

Refferences

Table Calculation

OBJECTIVE Engineering Survey 2

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Curve Ranging

At the end of the course the students should be able to develop skills on the use of engineering survey equipments and understand the theoretical and practical aspects of setting out the curve ranging.

INTRODUCTION

Curves are regular bends provided in the lines of communication like roads, railways etc. to bring about the gradual change of direction. They are also used in the vertical plane at all changes of grade to avoid the abrupt change of grade at the apex. Curves provided in the direction are known as horizontal curves, where as those provided in the vertical plane to obtain the gradual change in grade are known as vertical curves. In highways, railways, or canals the curve are provided for smooth or gradual change in direction due the nature of terrain, cultural features, or other unavoidable reasons. In highway practice, it is recommended to provide curves deliberately on straight route to break the monotony in driving on long straight route to avoid accidents. The horizontal curve may be a simple circular curve or a compound curve. For a smooth transition between straight and a curve, a transition or easement curve is provided. The vertical curves are used to provide a smooth change in direction taking place in the vertical plane due to change of grade.

EQUIPMENTS AND APPARATUS Engineering Survey 2

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Curve Ranging No.

Equipments and apparatus

1

Digital Theodolite

1

2

Tripod stand

1

3

Ranging pole

1

4

Arrow

14

Engineering Survey 2

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Total

Curve Ranging

5

Measuring tape

1

PROCEDURE

Engineering Survey 2

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Curve Ranging 1. The apparatus that need used was bring to the fieldwork. 2. Then the theodolite was set up at the one point.

Figure 1. setting up the apparatus 3. After that use a measuring tape to measure 25.198m straight line from the theodolite, then the end of the line was marked. 4. Then the person that handle the theodolite was given the other person command to move based on the cumulative angle.

Figure 2. Observing to the next sub-chord

5. Using an arrow, marked each line placed at 4m intervals accurately based on the cumulative angle given. 6. The set 4 and 5 was repeated until the cumulative angle at the table was done.

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Curve Ranging

Figure 3. Observing the last 3 sub-chord 7. And lastly, the point that we marked was observed.

RESULT Given, ɵ = 34˚ 58ˈ 00˝ R = 80 m CH1 = 502.315 m

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Curve Ranging Intervals = 4 m

Table Point

Chainage (m)

Chord length

Deflection

Cumulative

T T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 U

477.117 480 484 488 492 496 500 504 508 512 516 520 524 525.940

(m) 0 2.883 4 4 4 4 4 4 4 4 4 4 4 1.94

angle 0 01˚ 01ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 01˚ 25ˈ 56˝ 00˚ 41ˈ 41˝

angle 0 01˚ 01ˈ 56˝ 02˚ 27ˈ 52˝ 03˚ 53ˈ 48˝ 05˚ 19ˈ44 ˝ 06˚ 45ˈ 40˝ 08˚ 11ˈ 36˝ 09˚ 37ˈ 32˝ 11˚ 03ˈ 28˝ 12˚ 29ˈ 24˝ 13˚ 55ˈ 20˝ 15˚ 21ˈ 16˝ 16˚ 47ˈ 12˝ 17˚ 23ˈ 53˝

Calculation

i)

ɵ 2

IT = R Tan

= 80 Tan

34 ˚ 58 ˈ 2

= 25.198 m

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Curve Ranging

ii)

CHT = CH1 – IT = 502.315 – 25.198 = 477.117 m

iii)

LC = R ɵ rad = 80 × 34˚58ˈ ×

π 180 °

= 48.823 m iv)

CHu = CHT + LC = 474.117 + 48.823 = 525.940 m

DISCUSSION

Engineering Survey 2

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Curve Ranging

CONCLUSION

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Curve Ranging

REFERENCES

i)

Internet - Surveying Note Curve Ranging Chapter 6, http://www.scribd.com/doc/75576307/Surveying-Note-Curve-RangingChapter-6

ii)

Notes - Topic 4: Curve Ranging ( From lecturer)

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