SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN

BACHELOR OF SCIENCE ( QUANTITY SURVEYOR )

QSB 60103 SITE SURVEYING

Fieldwork 2 Report : Traversing

Group member :

Lim Chern Yie 0315688

Leong Chee Mun 0316256

Muhammad Hasif bin Alias 0316413

Liew Yong Sheng 0315108

Table of Content

Introduction 2

Apparatus of Fieldwork 5

Objective 7

Field Data 8

Summary 13

Reference 14

Introduction

Traversing is the method of using lengths and directions of lines between points to determine positions of the points. Traversing is normally associated with the field work of measuring angles and distances between points on the ground. It is a prevalent strategy for reviewing. This article incorporates meaning of navigate looking over alongside its classification,errors in crossing, checks, the finished strategy for navigating and plotting of cross overview.

Closed Traverse

A closed traverse is one enclosing a defined area and having a common point for its beginning to end. A closed traverse starts at a point and ends at the same point or at a point whose relative position is known. The surveyor adjusts the measurements by computations to minimize the effect of accidental errors made in the measurements. Large errors are corrected.

Opened Traverse

An open traverse begins at a beginning station, continues to its destination, and closures at a station whose relative position is not already known. It is the minimum attractive kind of navigate in light of the fact that it gives no keep an eye on hands on work or beginning information. Hence, the arranging of a traverse dependably accommodates conclusion of the cross. Crosses are shut in all situations where time licenses.

Station Selection

If the distance is measured with tape, the line between stations must be free of obstacles for the taping team. The surveyor should keep the number of stations in a traverse to a minimum to reduce the accumulation of instrumental errors and the amount of computing required. Short traverse legs require the establishment and use of a greater number of stations and may cause excessive errors in azimuth because small errors in centering the instrument, in station marking equipment, and in instrument pointings are magnified and absorbed in the azimuth closure as errors in angle measurement.

Meridians

Azimuth - The angular distance usually measured clockwise from the north point of the horizon to the intersection with the horizon of the vertical circle passing through a celestial body.

Bearing - Horizontal angles measured from the meridian either east or west.

Apparatus for Fieldwork

1) Theodolite

2) Tripod

A Theodolite is a instrument for measuring both horizontal and vertical angles, as used in triangulation networks, and geo-location work. It is a tool used in the land surveying and engineering industry, but theodolites have been adapted for other specialized purposes as well.

A tripod is a portable three-legged frame, used as a platform for supporting the weight and maintaining the stability of some other object. A tripod provides stability against downward forces, horizontal forces and moments about the vertical axis.

3) Plumb bob

4) Level Rod

A plumb bob or a plunge is a weight, for the most part with a pointed tip on the base, that is suspended from a string and utilized as a vertical reference line, or plumb line. It is basically what might as well be called a "water level".

A leveling rod is a reviewing device used to take height estimations with the end goal of profiling a segment of territory. There are various fundamental outlines accessible, including renditions for optical and computerized locating and record keeping. This tool is also known as a level staff, a reference to the original design, which was simply a tall staff with measurement markings.

Objective

- To determine the error of misclosure in order to determine whether the traversing is acceptable or not.

- To allow student to experience hands on working with a theodolite.

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

- To permit understudies to apply the hypotheses that had been taught in the classes in a hands- on circumstance, for example, making modification for every edge and in addition the scope and flight of each and every staff station keeping in mind the end goal to get the most exact results.

-To establish ground control in mapping

Field Data

Station Field Angles

A 96˚ 20' 00"

B 73˚ 14' 00"

C 88˚ 29' 00"

D 101˚ 30' 00"

Sum = 358˚ 93' 00"

359˚ 33' 00"

96˚20'00"73˚14'00"

101˚30'00"

88˚29'00"

28.00m

B

A

C

D

34.00m

38.00m

27.00m

Angular Error & Angle Adjustments ( 4 - 2 ) ( 180° ) = 360°, the sum of interior angles of the traverse must be 360°.

Total Angular error = 360˚00'00" - 359˚33'00" = 0˚27'00’’

∴ Error per angle = 0˚27'00’’ ÷ 4 = 0˚6'45’’ per angle

Station Field Angles Correction

Adjusted Angles

A 96˚20'00" + 6' 45’’ 96˚26'45"

B 73˚14'00" + 6' 45’’ 73˚20'45"

C 88˚29'00" + 6' 45’’ 88˚35'45"

D 101˚30'00" + 6' 45’’ 101˚36'45"

Sum = 358˚ 93'00" 360˚00'00"

Course Latitude & Departure

Station Bearing, βLength,

L

Cosine

( cos β )

Sine

( sin β )

Latitude

( L cos β )

Departure

( L sin β )

A S 83˚33'15" E 34.00m 0.11226 0.99368 - 3.82 + 33.79

B N 10˚12'30" W 38.00m 0.98417 0.17723 + 37.40 - 6.73

C S 78˚23'15" W 27.00m 0.20129 0.97953 - 5.43 - 26.45

D S 00˚00'00" E 28.00m - 1.00000 0.00000 - 28.00 + 0.00

Total 127.00m 0.15 0.61

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

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

= 0.628

P = 127.00

Accuracy = 1 : ( 127.00 / 0.621 ) = 1 : 202

∴The traversing is acceptable

Adjusted Latitude & Departure

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

Correction AB Lat = - ( 0.15 ) ÷ 127.00 x 34.00 = - 0.04

Correction BC Lat = - ( 0.15 ) ÷ 127.00 x 38.00 = - 0.05

Correction CD Lat = - ( 0.15 ) ÷ 127.00 x 27.00 = - 0.03

Correction DA Lat = - ( 0.15 ) ÷ 127.00 x 28.00 = - 0.03

Correction AB Dep = - ( 0.61) ÷ 127.00 x 34.00 = - 0.16

Correction BC Dep = - ( 0.61 ) ÷ 127.00 x 38.00 = - 0.18

Correction CD Dep = - ( 0.61 ) ÷ 127.00 x 27.00 = - 0.13

Correction DA Dep = - ( 0.61 ) ÷ 127.00 x 28.00Unadjusted Correction Adjusted

Station Latitude Departure Latitude Departure Latitude Departure

AB - 3.82 + 33.79 - 0.04 - 0.16 - 3.86 + 33.63

BC + 37.40 - 6.73 - 0.05 - 0.18 + 37. 35 - 6.91

CD - 5.43 - 26.45 - 0.03 - 0.13 - 5.46 - 26.58

DA - 28.00 + 0.00 - 0.03 - 0.14 - 28.03 - 0.14

Check + 0.15 + 0.61 - 0.15 - 0.61 0.0 0.0 = - 0.14

T able & Graph of Station Coordinates

N2 = N1 + Lat1-2

E2 = E1 + Dep1-2

Where :N2 and E2 = the Y and X coordinates of station 2N1 and E1 = the Y and X coordinates of station 1Lat 1-2 = the latitude course 1-2Dep 1-2 = the departure course 1-2

StationN Coordinate

Latitude E Coordinate

DepartureCourse Adj. Latitude

Adj. Departure

A100.00

(Assumed)100.00

(Assumed)

B 96.14 133.63 AB - 3.86 + 33.63

C 133.49 126.72 BC + 37. 35 - 6.91

D 128.03 100.14 CD - 5.46 - 26.58

A100.00

(Checked)100.00

(Checked)DA - 28.03 - 0.14

Summary

Main outcome from this field work is how closed loop traverse is being used.

Theodolite is much more complicated than the normal levelling method. However, the

equipment itself provide varieties of information and function. The main aim is to get the

angle from one station to another in a closed traverse.

We learned how to apply Stadia principle by using the theodolite to get out length.

The measurement of the length from theodolite to the levelling staff is quite simple. In the

vision through theodolite, we are able to receive 3 horizontal line act as a marking (top,

middle and bottom). By subtracting the top and bottom, we are able to get the length

easily.

By applying all the method shown in this report, it clearly proved that theodolite are

able to obtain accurate data of the field with some work of adjusting. It is a relief to know

that we do not need to redo it as setting up the theodolite already consume our working

time up to 10-15 minutes.

References

1. Stadia Principles. (n.d.). Retrieved July 1, 2015, from

https://engineering.purdue.edu/~asm215/topics/stadia.html

2. Irvine, W. H., & Maclennan, F. (2006). Surveying for construction. New

York: McGraw-Hill.

3. Whyte, W. S., & Paul, R. E. (1997). Basic surveying. Routledge.