site surveying report 2 (traversing)

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BQS MARCH 2014- QSB 60103 Fieldwork 2 Report 1 | Page SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN BACHELOR OF QUANTITY SURVEYING (HONOURS) QSB 60103 - SITE SURVEYING Fieldwork 2 Report Traversing Name Student ID Marks SHARON CHOW CI YUNG 0313387 TAN CHUU YEE 0315097 MUHAMMAD HAZIQ BIN HAJI ABD ZARIFUL 0314131 PARHAM FARHADPOOR 0313698

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Page 1: Site Surveying Report 2 (Traversing)

BQS MARCH 2014- QSB 60103 Fieldwork 2 Report

1 | Page

SCHOOL OF ARCHITECTURE, BUILDING AND

DESIGN

BACHELOR OF QUANTITY SURVEYING (HONOURS)

QSB 60103 - SITE SURVEYING

Fieldwork 2 Report

Traversing

Name Student ID Marks

SHARON CHOW CI YUNG

0313387

TAN CHUU YEE

0315097

MUHAMMAD HAZIQ BIN HAJI ABD ZARIFUL

0314131

PARHAM FARHADPOOR

0313698

Page 2: Site Surveying Report 2 (Traversing)

BQS MARCH 2014- QSB 60103 Fieldwork 2 Report

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Table of Contents

Content Page

Cover Page 1

Table of Content 2

1.0 Introduction to Traversing 3

1.1 Closed Traverse 3

1.2 Open Traverse 4

1.3 Station Selection 4

1.4 Azimuth 5

1.5 Bearing 5

1.6 Acceptable Misclosure 6

2.0 Outline of Apparatus 7

2.1 Theodolite 7

2.2 Tripod 8

2.3 Plumb Bob 8

2.4 Ranging Rod 9

2.5 Tape-Measure 9

3.0 Objectives 10

4.0 Field Data 11

4.1 Angular Error & Angle Adjustments 12

4.2 Course Bearings & Azimuths 13

4.3 Course Latitude & Departure 14

5.0 Adjusted Latitude & Departure 15

6.0 Table and Graph of Station Coordinates 16-17

7.0 Summary 18

8.0 References 19

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1.0 Introduction to Traversing

Traversing is one of the traditional methods of carrying out a control survey in plan. Stations

are set out to define a series of traverse lines or legs, the plan length of which can be

measured as can the angles between pairs of line at each station (Muskett, 1995).

There are two types of traverse:

1.1 Closed Traverse

Closed Traverses provide a check on the validity and accuracy of field measurements.

There are two types of closed traverse which are the loop traverse and connecting traverse.

Loop traverse starts and ends at the same point, forming a polygon. Loop traverse is

suitable for many engineering surveys.

Figure 1.0 Loop Traverse

Source:

http://files.carlsonsw.com/mirror/manuals/SightSurvey_2009/scr/Section%2011%20-

%20Tools%20Menu/images/CG_Editor/cge001.png

On the other hand, connecting traverse is similar to open traverse, the only difference is it

begins and end at point of known position at each end of traverse.

Figure 1.1 Loop Traverse Source: http://www.tpub.com/engbas/13.htm3.gif

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1.2 Open Traverse

Open Traverses are a series of measured straight lines and angles that do not close

geometrically and provide no check and are not recommended. They are usually being

applied in underground surveys.

Figure 1.2 Open Traverse

Source: http://www.tpub.com/engbas/13.htm3.gif

1.3 Station Selection

The stations should be marked out firmly and clearly as well as strongly referenced. The

following are the requirements for the selection of traversing stations (Muskett, 1995):

i) The stations should form a traverse of suitable shape.

ii) Only neighbouring stations along traverse lines need be intervisible.

iii) Where traverse legs are to be taped, the ground should be accessible.

iv) Traverse legs should be approximately equal in length.

v) Existing stations and reference objects should be incorporated.

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1.4 Azimuth

An azimuth is an angle between 0° and 360° measured clockwise from North (Penn State

College of Earth and Mineral Sciences, 2014).

1.5 Bearing

A bearing is an angle less than 90° within a quadrant defined by the cardinal directions (Penn

State College of Earth and Mineral Sciences, 2014).

Figure 1.3 Azimuth and Bearing

Source: https://www.e-

education.psu.edu/geog160/files/geog160/image/Chapter05/Azimuths_Bearings.png

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1.6 Acceptable Misclosure

Generally for land surveying, an accuracy of 1:3000 is typical. The range of acceptable

misclosure can be calculated with the following formula:

Accuracy= 1: (P/Ec)

P= Perimeter of the Entire Traverse

Ec= The Total Error

Table 1.0 Traverse Specification in United States of America.

Source: Federal Control Committee, United States (1974).

Classification First Order Class I (Second

Order) Class II (Second

Order) Class I (Third

Order) Class II (Third

Order)

Recommended spacing of principal

stations.

Network stations 10 to 15 km other surveys seldom less

than 3 km.

Principal stations seldom less than 4km, except in metropolitan area surveys, where the limitation is

0.3km.

Principal stations seldom less than 2km, except in metropolitan area surveys where the

limitation is 0.2km.

Seldom less than 0.1 km in tertiary surveys in metropolitan area surveys; as required for

other surveys.

Seldom less than 0.1 km in tertiary surveys in metropolitan area surveys; as required for

other surveys.

Position closure

After azimuth

adjustment.

0.04m √k or

1: 100,000

0.08m √k or

1:50,000

0.08 m √k or

1:20,000

0.2m √k or

1: 10,000

0.8m √k or

1:5000

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2.0 Outline of Apparatus

2.1 Theodolite

The basic instrument for setting out lines and angles over wide distances. The original theodolite was a purely optical instrument, but nowadays most theodolites come with an electronic distance-measuring attachment commonly known as the EDM (Food and Agriculture Organization of the United Nations, n.d.).

Figure 2.0 Theodolite

Source: http://www.vpcivil.co.in/wp-content/uploads/2012/08/Topcon-Dt-200-Digital-

Theodolite.jpg

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2.2 Tripod

The tripod is used solely for setting up the theodolite or the level (Food and Agriculture Organization of the United Nations, n.d.).

Figure 2.1 Tripod

Source: http://www.ysf.com.hk/images/SJA50%20Aluminum%20Tripod-1-c.jpg

2.3 Plumb Bob

The plumb bob or plumb line employs the law of gravity to establish what is “plumb” (that is,

what is exactly vertical, or true). In a sense, the plumb bob is the vertical equivalent of the

line level (Bob Vila, 2014).

Figure 2.2 Plumb Bob

Source: http://www.archtools.eu/images/detailed/0/plumbbob.jpg

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2.4 Ranging Rod

Ranging rods are coloured poles used in tracing out lines on the ground. Ranging rods can either be purchased outright or made from pieces of straight pipe, roughly 1.5 m long, with red and white bands (150 mm wide) painted as shown in Figure 2.3.

Figure 2.3 Ranging Rod

Source: http://www.nsscanada.com/Images/Prism_Poles/CST001quickrelease.jpg

2.5 Tape-Measure

Fibre or plastic tape-measures typically come in lengths of 20, 30, 50 or 100 m (Food and Agriculture Organization of the United Nations, n.d.).

Figure 2.4 Fiberglass Tape-Measure

Source:

http://i01.i.aliimg.com/img/pb/585/870/210/1234350266708_hz_myalibaba_web7_1249.jpg

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3.0 Objectives

• To enhance the students’ knowledge in the traversing procedure.

• To enable students to get hands-on experience in setting up and working with the

theodolite.

• To determine the error of misclosure in order to determine whether the traversing is

acceptable or not.

• To allow students to apply the theories that had been taught in the classes in a

hands- on situation such as making adjustments for each angle as well as the

latitude and departure of every single staff station in order to obtain the most

accurate results.

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4.0 Field Data

Station Field Angles

A 73° 47’ 30’’

B 107° 35’ 20’’

C 72° 23’ 00’’

D 106° 12’ 00’’

Sum= 358° 117’ 50’’

359° 57’ 50’’

(not to scale)

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4.1 Angular Error & Angle Adjustments

(4-2)(180°)= 2(180°)= 360°, the sum of interior angles of the traverse must be

360°

Total angular error = 359°57’50’’- 360° = 0° 2’ 10’’

Therefore, error per angle = 0° 2’ 10’’÷5 = 130’’÷5 = 32.5’’ per angle

Station Field Angles Correction Adjusted Angles

A 73° 47’ 30’’ +32.5’’ 73° 48’ 2.5’’

B 107° 35’ 20’’ +32.5’’ 107° 35’ 52.5’’

C 72° 23’ 00’’ +32.5’’ 72° 23’ 32.5"

D 106° 12’ 00’’ +32.5’’ 106° 12’ 32.5’’

Sum= 358° 117’ 50’’ 360° 00’ 00’’

359° 57’ 50’’

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4.2 Course Bearing & Azimuth

73° 48’ 2.5’’ N73° 48’ 2.5’’E

S0°00’00’’E 180°00’00’’

N73°47’32.5’’E 252°47’27.5’’

252°47’27.5’’

-180°00’00’’

73°47’32.5’’

180°00’00’’

+1°23’55’’

+72°23’32’5"

252°47’27.5’’

1°23’55’’

180°00’00’’

+107° 35’ 52.5’’

+73° 48’ 2.5’’ 361°23’55’’

-360°00’00’’

1°23’55’’

N1°23’55’’E

Azimuth N Bearing

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4.3 Course Latitude & Departure

Accuracy= 1 : (P/Ec), typical=1:3000

Ec = [(sum of latitude)2 + (sum of departure)2 ]1/2

= 0.045 P = 156.27

Accuracy = 1: (156.27/0.045) = 1: 3473

∴The traversing is acceptable

cosβ sinβ Lcosβ Lsinβ

Station Bearing, β Length, L Cosine Sine Latitude Departure

A N73° 48’ 2.5’’E 12.48 0.2789795 0.9602970 +3.4819 -11.9845

B N1°23’55’’E 64.46 0.9997021 0.024407 +65.1405 +1.5899

C N73°47’32.5’’E 14.17 -0.2791421 -0.9602498 -3.9548 -13.6060

D S0°00’00’’E 65.16 -1.00000 0.00000 -64.7000 0.0000

TOTAL 156.27 -0.0324 -0.0316

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5.0 Adjusted Latitude & Departure

Compass Rule:

Correction = - [∑Δy] ÷ P x L or - [∑Δx] ÷ P x L

CorrectionAB Lat= -(-0.0324) ÷ 156.27 x 12.48

= +0.0026

CorrectionBC Lat= -(-0.0324) ÷ 156.27 x 64.46

= +0.0135

CorrectionCD Lat= -(-0.0324) ÷ 156.27 x 14.17

= +0.0029

CorrectionDA Lat= -(-0.0324) ÷ 156.27 x 65.16

= +0.0134

CorrectionAB Dep= -(-0.0316) ÷ 156.27 x 12.48

= +0.0025

CorrectionBC Dep= -(-0.0316) ÷ 156.27 x 64.46

= +0.0131

CorrectionCD Dep= -(-0.0316) ÷ 156.27 x 14.17

= +0.0029

CorrectionDA Dep= -(-0.0316) ÷ 156.27 x 65.16

= +0.0131

Unadjusted Corrections Adjusted

Station Latitude Departure Latitude Departure Latitude Departure

A +3.4819 -11.9845 +0.0026 +0.0025 +3.4845 +11.9870

B +65.1405 +1.5899 +0.0135 +0.0131 +65.1540 +1.6030

C -3.9548 -13.6060 +0.0029 +0.0029 -3.9519 -13.6031

D -64.7000 0.0000 +0.0134 +0.0131 -64.6866 +0.0131

Check -0.0324 -0.0316 +0.0324 +0.0316 0.00 0.00

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6.0 Table & Graph of Station Coordinates

N2 = N1 + Lat1-2

E2 = E1 + Dep1-2

Where:

N2 and E2 = the Y and X coordinates of station 2

N1 and E1 = the Y and X coordinates of station 1 Lat1-2 = the latitude course 1-2

Dep1-2 = the departure course 1-2

Course Adjusted

Latitude

Adjusted

Departure

Station N Coordinate

Latitude (y-axis)

E Coordinate

Departure (x-axis)

A 100.0000(Assumed) 100.0000(Assumed)

AB +3.4845 +11.9870 B 103.4845 111.9870

BC +65.1540 +1.6030 C 168.6385 113.5900

CD -3.9519 -13.6031 D 164.6866 99.9869

DA -64.6866 +0.0131 A 100.0000 (Checked) 100.0000 (Checked)

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7.0 Summary

In this fieldwork, closed loop traverse is being used. For our first attempt,

we shared the theodolite with another group and used the pacing method to

obtain our length of each course but we failed to get an accuracy of at least

1:3000. For our second attempt, we used the tape-measure to measure the

length of each course. In order to get the most accurate reading possible, our

lecturer, Mr.Chai taught us to use the theodolite to guide our tape-measure to

make sure it is in a straight line.

Our error in departure is -0.0316 and our error in latitude is -0.0324. The

total error is 0.045.Using the following formula, we calculated the accuracy of

our traverse survey:

Accuracy = 1: Perimeter/ Error Closure

We obtained an accuracy of 1: 3473. For average land

surveying an accuracy of 1:3000 is typical. Therefore, our traverse survey is

acceptable.

For the adjustment of latitude and departure, we used the compass rule,

using the following formula:

Correction = - [∑Δy] ÷ P x L or - [∑Δx] ÷ P x L

Where:

∑Δy or ∑Δx = the error in latitude & departure

P = The total length or perimeter of the traverse

L = The length of the particular traverse

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8.0 References

Bob Vila (n.d.). The Plumb Bob. (Website). Retrieved on 20th November 2014 from

http://www.bobvila.com/articles/495-the-plumb-bob/#.VHbzzTGUeoh

Federal Geodetic Control Committee (1984). Standard Specifications for Geodetic Control

Networks. Retrieved on 20th November from

http://www.ngs.noaa.gov/FGCS/tech_pub/1984-stds-specs-geodetic-control-

networks.pdf

Food and Agriculture Organization of United Nations (n.d.). Making a Site Survey. (Website).

Retrieved on 20th November 2014 from

http://www.fao.org/docrep/v5270e/v5270e02.htm

Muskett, M. (1995). Site Surveying. (2nd ed). Oxford, United Kingdom: Blackwell Science Ltd.

Penn State College of Earth and Mineral Sciences (2014). Land Surveying and Conventional

Techniques for Measuring Positions on the Earth’s Surface. Retrieved on 20th

November 2014 from https://www.e-education.psu.edu/geog160/node/1926