1 | P a g e

SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN

BACHELOR OF QUANTITY SURVEYING (HONOURS)

QSB 60103- SITE SURVEYING

Fieldwork 1 Report

Levelling

Name Student ID Marks

SHARON CHOW CI YUNG 0313387

TAN CHUU YEE 0315097

MUHAMMAD HAZIQ BIN HAJI ABD ZARIFUL

0314131

PARHAM FARHADPOOR 0313698

Table of Content

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

2 | P a g e

Content Page

Cover Page 1

Table of Content 2

1.0 Introduction to Levelling 3-4

2.0 Outline of Apparatus 5

2.1 Automatic Level 5

2.2 Adjustable Leg-Tripod 6

2.3 Optical Plummet 7

2.4 Horizontal Bubble Level 8

2.5 Bar- Coded Level Rod 8

3.0 Objectives 9

4.0 Field Data 10

4.1 Rise and Fall Method 10

4.2 Height of Collimation Method 11

5.0 Adjusted Data 12

5.1 Rise and Fall Method 12

5.2 Height of Collimation Method 13

6.0 Summary 14

7.0 References 15

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

3 | P a g e

1.0 Introduction to Levelling

Levelling is the determination of the relative heights (altitudes) of the different points in

the area under survey, it is this information which, when coupled with that of the pan, enables a

section through the land and/or artefacts to be drawn (Clancy, 1991).

A horizontal line (or plane) of sight (line or plane of collimation) is established with a

telescope (fitted with cross-hairs) which can be turned about a vertical axis. The difference in

consecutive readings taken on a vertical staff gives the level difference between two points

which can be seen in the figure below.

Figure 1.0 Levelling

Source: http://www.colorado.edu/geography/courses/geog_2043_f01/lab4/diff.jpg

Backsight (B.S.) - The first reading from a new instrument position.

Intermediate Sight (I.S.) – Readings between the backsight (B.S.) and foresight (F.S.)

Foresight (F.S.) - The last reading from an instrument position.

There leveling has two type of layouts which are the rise and fall method and the height

of collimation method.

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

4 | P a g e

Figure 1.1 Height of Collimation Method

Source: http://gmba-learning-gateway.co.uk/images/Height_of_Col.jpg?713

Figure 1.2 Rise and Fall Method

Source: http://constructionsite.org.uk/repository/resource/view_resource.php?

id=122&backname=study_unit

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

5 | P a g e

2.0 Outline of Apparatus

2.1 Automatic Level - An Auto-Level is a Professional Leveling Tool used by Contractors,

Builders, Land Surveying Professionals, or the Engineer who demands accurate leveling every

time ( Engineering Supply, 2014).

Figure 2.0 Automatic Level

Source: http://www.engineersupply.com/Images/cst-berger-leveling-aligning-contractor-

tools/ES1008-CST-Berger-24X-SAL-Automatic-Level-55-SAL24ND-md.jpg

2.2 Adjustable Leg-Tripod- Adjustable-leg tripods are the more common of the two in the

construction world, especially outdoors because of generally uneven terrain. The adjustable-leg

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

6 | P a g e

tripod is easier to set up on uneven ground because each leg can be adjusted to exactly the

height needed to find level, even on a very steep slope (Johnson Level, 2010).

Figure 2.1 Adjustable Leg- Tripod

Source: http://www.gotechequipment.com/laser%20images/GOtripod-1.jpg

2.3 Optical Plummet - A device used in place of a plumb bob to center transits and theodolites

over a given point, preferred for its steadiness in strong winds (Dictionary of Construction.com,

2014).

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

7 | P a g e

Figure 2.2 Optical Plummet

Source:

http://www.sccssurvey.co.uk/media/catalog/product/cache/1/image/650x650/9df78eab33525d08

d6e5fb8d27136e95/l/e/leica_gdf111-1_tribrach_without_optical_plummet.jpg

2.4 Horizontal Bubble Level - Tool for determining whether a surface is horizontal (The

Columbia Encyclopedia, 2014).

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

8 | P a g e

Figure 2.3 Horizontal Bubble Level

Source: http://image.made-in-china.com/43f34j00KvltAoQabOqR/Staff-Level.jpg

2.5 Bar- Coded Level Rod – To determine the relative heights of the different points in the area

under survey (Clancy, 1991).

Figure 2.4 Bar- Coded Level Rod

Source: http://www.testoon.com/images_produit/005838-full.jpg

3.0 Objectives

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

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

9 | P a g e

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

level.

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

acceptable or not.

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

situation such as making adjustments for each reduced level of every single staff station

in order to obtain the most accurate reduced levels.

• To identify the reduced level of each staff station.

4.0 Field Data

4.1 Rise and Fall Method

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

10 | P a g e

BS IS FS Rise Fall R.L. Remarks

1.458 100.000 BM1

1.390 3.679 2.221 97.779 TP A

1.619 1.502 0.112 97.667 TP B

1.243 1.535 0.084 97.751 TP C

1.553 1.488 0.245 97.506 TP D

1.276 1.269 0.284 97.790 TP E

1.274 1.300 0.024 97.766 TP F

1.627 1.436 0.162 97.604 TP G

3.571 1.489 0.138 97.742 TP H

1.348 1.338 2.233 99.975 TP I

1.329 0.019 99.994 BM1

∑BS=16.359 ∑FS=16.365 ∑Rise=2.75

8

∑Fall=2.764

Arithmetical Check :

∑BS-∑FS= ∑Rise-∑Fall= Last Reduced Level Reading- First Reduced Level Reading

16.359-16.365 = 2.758-2.764 = 99.994-100.000

-0.006 = -0.006 = -0.006

Acceptable Misclosure= 12+/- √k

K= the number of set-ups

12+/-√10= +/-37.947mm

∴ The levelling is acceptable

4.2 Height of Collimation Method

BS IS FS Height of Collimation R.L. Remarks

1.458 101.458 100.000 BM1

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

11 | P a g e

1.390 3.679 99.169 97.779 TP A

1.619 1.502 99.286 97.667 TP B

1.243 1.535 98.994 97.751 TP C

1.553 1.488 99.059 97.506 TP D

1.276 1.269 99.066 97.790 TP E

1.274 1.300 99.040 97.766 TP F

1.627 1.436 99.231 97.604 TP G

3.571 1.489 101.313 97.742 TP H

1.348 1.338 101.323 99.975 TP I

1.329 99.994 BM1

∑BS=16.359 ∑FS=16.365

Arithmetical Check :

∑BS-∑FS= = Last Reduced Level Reading- First Reduced Level Reading

16.359-16.365 = 99.994-100.000

-0.006 = -0.006

Acceptable Misclosure= 12+/- √k

K= the number of set-ups

12+/-√10= +/-37.947mm

∴ The levelling is acceptable.

5.0 Adjusted Data

5.1 Rise and Fall Method

BS IS FS Rise Fall R.L. Adj. Final

R.L.

Remarks

1.458 100.000 100.0000 BM1

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

12 | P a g e

1.390 3.679 2.221 97.779 +0.0006 97.7796 TP A

1.619 1.502 0.112 97.667 +0.0012 97.6682 TP B

1.243 1.535 0.084 97.751 +0.0018 97.7528 TP C

1.553 1.488 0.245 97.506 +0.0024 97.5084 TP D

1.276 1.269 0.284 97.790 +0.0030 97.7930 TP E

1.274 1.300 0.024 97.766 +0.0036 97.7696 TP F

1.627 1.436 0.162 97.604 +0.0042 97.6082 TP G

3.571 1.489 0.138 97.742 +0.0048 97.7468 TP H

1.348 1.338 2.233 99.975 +0.0054 99.9804 TP I

1.329 0.019 99.994 +0.0060 100.0000 BM1

Correction per set-up

= Error of misclosure ÷ Number of set up

= (100.0000-99.9940)÷10

= +0.0006 m

5.2 Height of Collimation Method

BS IS FS Height of

Collimation

R.L. Adj. Final R.L. Remarks

1.458 101.458 100.000 100.0000 BM1

1.390 3.679 99.169 97.779 +0.0006 97.7796 TP A

1.619 1.502 99.286 97.667 +0.0012 97.6682 TP B

1.243 1.535 98.994 97.751 +0.0018 97.7528 TP C

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

13 | P a g e

1.553 1.488 99.059 97.506 +0.0024 97.5084 TP D

1.276 1.269 99.066 97.790 +0.0030 97.7930 TP E

1.274 1.300 99.040 97.766 +0.0036 97.7696 TP F

1.627 1.436 99.231 97.604 +0.0042 97.6082 TP G

3.571 1.489 101.313 97.742 +0.0048 97.7468 TP H

1.348 1.338 101.323 99.975 +0.0054 99.9804 TP I

1.329 99.994 +0.0060 100.0000 BM1

Correction per set-up

= Error of misclosure ÷ Number of set up

= (100.0000-99.9940)÷10

= +0.0006 m

6.0 Summary

In this fieldwork, the reduced level of Bench Mark (BM) 1 is given which is 100.00m. The

leveling process begins with obtaining the backsight (BS) of BM1 and the foresight (FS) of

turning point (TP) A. Then the auto level is shifted to obtain the BS of TP A and the FS of TP B.

This process is repeated by shifting the auto level to obtain the BS and FS of the following staff

stations and lastly go back to BM1 to obtain its FS in order to calculate the error of misclosure.

We used both the rise and fall method and the height of collimation method to calculate

the reduced level of each staff station. The error of misclosure was -0.006mm and the

acceptable range of error of misclosure was calculated using the 12+/- √k formulae where k

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

14 | P a g e

represents the number of set-ups, and the acceptable range of error of misclosure is +/-

37.947mm. Thus, our leveling is acceptable.

To distribute the error, the correction per set-up is calculated using the following

formulae:

Correction per set-up

= Error of misclosure ÷ Number of set up

The correction per-set up is +0.0006m and is cumulative as shown in the table provided

in the adjusted data section.

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report

15 | P a g e

7.0 References

Clancy, J. (1991). Site Surveying and Leveling. (2nd ed). London, United Kingdom: Arnold.

Dictionary of Consturction.com. (2014). optical plummet. (Website). Retrieved on 13th

November, 2014 from http://www.dictionaryofconstruction.com/definition/optical-

plummet.html

Encyclopedia.com.(2014). spirit level. (Website). Retrieved on 13th November, 2014, from

http://www.encyclopedia.com/topic/spirit_level.aspx

EngineerSupply. ( 2014). Automatic Levels. (Website). Retrieved on 13th November, 2014, from

http://www.engineersupply.com/automatic-levels.aspx

Johnson Level & Tool. (2014). What is a Tripod? How do Tripods for Laser Levels Work?

Retrieved on 13th November, 2014 from

http://www.johnsonlevel.com/News/WhatisaTripodHowdoTripods

Macbain, G. (n.d.). Book Levels. (Website). Retrieved on 13th November, 2014 from

http://constructionsite.org.uk/index.php?/content/view/150/7ef605fc8dba5425d6965f

bd4c8fbe1f/open/cab34bec95719831380345d7068f5457/unit/29/key/6ea9ab1baa0e

fb9e19094440c317e21b/chapter/3

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

BQS MARCH 2014- QSB 60103 Fieldwork 1 Report