Site surveying report ii

SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN

BACHELOR OF QUANTITY SURVEYING (HONOURS)

QSB1813 – Site Surveying

Field Work Report IITraverse Survey

August Semester 2013

Submission Date: 4th December 2013

Name Student ID Marks

Low Rong Tzuoo 0308336

Rueul Chan Ernyi 0315150

Wong Choong Ling 0314504

Yam Yih Hwan 0305861

Table of Content Page

1 Site Surveying - Report II (Traverse Survey)

Cover Page 1

Table of Content 2

Introduction to Traverse Survey 3 - 4

Objective 5

Outline of Apparatus 6 - 7

Traverse Survey Result 8 - 10

Discussion 11

Conclusion 12

Learning Outcomes 13

Introduction to Traverse Survey


Traversing is a type of survey in which a number of connected survey lines form the framework and the directions and lengths of the survey lines are measured with the help of an angle measuring instrument and a tape or chain respectively.

There are two types of traverse surveying,

Closed traverse: When the lines form a circuit which ends at the starting point, it is known as closed traverse.

Open traverse: When the lines form a circuit ends elsewhere, it is said to be an open traverse.

The closed traverse is suitable for locating the boundaries of lakes, woods, etc. and for survey of large areas. The open traverse is suitable for surveying a long narrow strip of land as required for a road of canal or the coast line.

The most satisfactory method of checking the linear measurements consists in chaining each survey line a second time, preferably in the reverse direction on different dates and by different parties.


Introduction to Traverse Survey

The direction of a line is defined by a horizontal angle between the line and an arbitrarily chosen reference line called a meridian.

The types of meridians (and thus directions) are,

Geodetic: Angle generally measured from geodetic north. Historically south has occasionally been used.

Magnetic: Angle measured from magnetic north. Since magnetic fields fluctuate over time, this meridian is time-dependent.

Grid: Angle measured from grid (map) north. This angle is dependent on the map-projection.

The types of directions are,

Azimuths: Horizontal angles measured clockwise from a reference meridian. Azimuths can be any of the type above, geodetic azimuth, astronomic azimuth, etc. For examples, 34°, 157°, 235°, 317°.

Bearings: Horizontal angles measured from the meridian either east or west. They can be geodetic, astronomic, etc. Thus they are designated with nomenclature;

Require two letters and an acute angle (<90°) Measured both clockwise and counter-clockwise Can be measured from North or South axis of meridian


Objective

To determine the positions of existing boundary

To establish the positions of boundary lines

To determine the area encompassed within a boundary

To establish ground control for photographic mapping


Outline of Apparatus

Theodolite is a device used widely to determine the horizontal and vertical angles, distance, depths, etc. Besides that, it is used to identify the ground level and the ways to construct super-structure or sub-structure. A basic theodolite consists of a small sized telescope with the mechanism to measure horizontal and vertical angles. Theodolite is able to rotate 360 degree on a tripod stand by a levelling system. The angle can be measured on the scale on the tripod. The calculation of the theodolite is based on the principal of trigonometry, as used in triangulation network. It is a key tool in surveying and engineering work.

Tripod is a rigid type of stand that is capable of fixing minor lateral movement on its top when required. It is used to support the other components of theodolite including the telescope.

Horizontal bubble level is an instrument used to indicate the horizontal level. A slightly curved glass tube which in incompletely filled with either spirit or alcohol.

Plumbob is a weight with a pointed bottom that is suspended from a string to determine a vertical reference line or the Y-axis. It is used to mark a point directly under the theodolite.


Outline of Apparatus

Theodolite Pole is used as a stand to indicate the angle between two or more point in an enclosed area. The angle is measures by setting 0 degree on the theodolite towards the first pole and is rotate from left to right to the second pole.

Theodolite Telescope is an instrument used to view distant object. Telescope is an arrangement of lens that gather visible light, permitting direct observation of a point through the theodolite in a distance. There is a focusing screw to adjust the clarity of the view in the telescope.


Traverse Survey Result


Interior Angle Adjusted Interior Angle WCB

A 147° 147° 22'30 ' ' AB 147° 22'30 ' '

B 63° 30’ 63° 52' 30 ' ' BC 147° 22'30 ' '+¿63° 52' 30 ' ' - 180°

= 31°15’

C 108° 108° 22'30 ' ' CD 31°15’ +108° 22'30 ' ' + 180°

= 319° 37’ 30’’

D 40° 40° 22'30 ' ' DA 319° 37’ 30’’ + 40° 22'30 ' ' - 180°

= 180°


Interior Angle= (n-2) * 180°

= (4-2) * 180°

= 360°

Adjustment = 360°−¿147°−63 ° 30'−108 °−40°

= (1° 30') / 4

= 0° 22'30 ' '

∆ E=l sin (WCB )

∆ N=l cos (WCB )

Length of AB = 4.15 m

Length of BC = 3.65 m

Length of CD = 6.42 m

Length of DA = 4.52 m

Total length of ABCD = 18.74 m



∆ E=l sin (WCB ) Adjustment ∆ E

= - 0.028 ×length

total length

Adjusted ∆ E

A 2.237 - 6.201 ×10−3 2.243

B 1.894 - 5.454 ×10−3 1.899

C - 4.159 - 9.592 ×10−3 - 4.149

D 0 - 6.753 ×10−3 0.007

- 0.028

∆ N=l cos (WCB ) Adjustment ∆ N

= - 0.004 ×length

total length

Adjusted ∆ N

A - 3.495 - 0.886 ×10−3 - 3.494

B 3.120 - 0.779 ×10−3 3.121

C 4.891 - 1.370 ×10−3 4.892

D - 4.520 - 0.963×10−3 - 4.519

- 0.004

Assuming that the coordinates of A is (1000, 1000).

Coordinates of

∆ E ∆ N

A 1000.000 1000.000

B 1001.899 1003.121

C 997.750 1008.013

D 997.757 1003.494


Discussion

Points A, B, C, D are laid out on the site respectively. The theodolite is placed at point A, and the angle of point A is achieved by reading the theodolite through point D to B. The angles of the theodolite must be read from left to right in order to obtain a more accurate reading.

The zero angles set on point D, and turned the theodolite all the way to the right until point B is achieved. The reading of the angle on the theodolite has to be recorded. The telescope is transited and the ‘hold’ button is pressed to preserve the angle, so that the recording becomes more accurate. This process is repeated at each of the points on the site to obtain the angles from each point.

At the end of the process, the total recorded angles must be 360°. However, in our report, the total angle recorded is 358° 30’. Thus, error has occurred as there is a difference of 1° 30’. Therefore, adjustment has to be made, by using the trigonometric levelling technique.


Conclusion

In conclusion, the angles are obtained through the usage of equipment provided by lecturer. However, we were unable to obtain the exact 360°; therefore adjustment was made in order to achieve 360°. Lastly, we conducted a field work report.


Learning Outcomes

Able to conduct a fieldwork report regarding on traverse survey

Get to experience the equipment on site

Learning the correct ways of doing survey

Able to obtain the angle through the usage of equipment

Able to identify the errors & perform an adjustment


Technology

Site surveying report ii