Site survey Fieldwork 2 traversing
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The document describes a site surveying fieldwork involving a closed loop traverse using a theodolite. Key steps included setting up the instrument and marking stations A, B, C and D. Field angles were measured between stations and used to calculate distances, azimuths, latitudes and departures. The total angular error was distributed and corrections applied to adjusted values. Station coordinates were then computed, with the traverse closing within the acceptable accuracy range for land surveying of 1:300. The purpose was to gain practical experience in traversing techniques.
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SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
[QSB 60203] SITE SURVEYING
FIELDWORK 2
Traversing
NAME STUDENT ID
NG SHENG ZHE 0323830
SEW YUE LING 0327032
LIEU XUE QI 0327523
PHON KIT POI 0328435](https://image.slidesharecdn.com/fieldwork2-161208143210/85/Site-survey-Fieldwork-2-traversing-1-320.jpg)
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Correction = – [ ∑∆y ] / P x L or – [ ∑∆x ] / P x L
Where,
∑∆y and ∑∆x = The error in latitude and departure
P = Total length of perimeter of the traverse
L = Length of a particular course Station
Accuracy = 1: (P/Ec)
Therefore, the accuracy = 1: (91.20/0.0257)
= 1: 3548.6
= 1: 3549
For average land surveying, an accuracy of about 1:300 is typical.
Thus, the accuracy of field is acceptable.
A
A’
Error in departure
∑∆𝑥 = +0.0168 𝑚
Error in latitude
∑∆𝑦 = −0.0194 𝑚
Ec, Total Error
91.20 m](https://image.slidesharecdn.com/fieldwork2-161208143210/85/Site-survey-Fieldwork-2-traversing-14-320.jpg)
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Adjusted Course Latitude & Departure
The compass rule:
Correction = -[y]P x L or - [x]P x L
Latitude Correction
The correction to the latitude:
Course A-B is
[-0.0194÷ 91.20] x 16.85 = -0.00358
Course B-C is
[-0.0194÷ 91.20] x 29.05 = -0.00618
Course C-D is
[-0.0194÷ 91.20] x 16.45 = -0.00350
Course D-A is
[-0.0194÷ 91.20] x 28.85 = -0.00614
Departure Correction
The correction to the departure:
Course A-B is
[0.0168÷ 91.20] x 16.85 = 0.00310
Course B-C is
[0.0168÷ 91.20] x 29.05 =0.00535
Course C-D is
[0.0168÷ 91.20] x 16.45 = 0.00303
Course D-A is
[0.0168÷ 91.20] x 28.85 =0.00531](https://image.slidesharecdn.com/fieldwork2-161208143210/85/Site-survey-Fieldwork-2-traversing-15-320.jpg)
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Summary
In this second fieldwork, we are required to do a closed loop traverse by using a theodolite at
the carpark in Taylor’s University Lakeside Campus. The first thing we did is to set up the
instrument and to mark four points for station which are station A, B, C and D. Before we took
the measurement, we levelled the theodolite.
First of all, we know that the point A, B, C and D are laid out on the site respectively. The
theodolite is placed at station A which is our starting point and adjust it until it is in horizontal
level. Besides, the other stations (A, B, C, D) must be stated on the site to form a loop traverse
by using liquid ink. After that, we used theodolite to measure the angles of four stations as our
field data. As we taught in class that the horizontal reading must be taken twice which is the first
reading is taken, then turn back again to take the second reading. The angles of the theodolite
must be read from left to right in order to obtain a more accurate reading.
In order to obtain the angles form each point, the process is repeated at each of the points on
the site. During the measurement, the vertical and horizontal angles will be shown on the digital
readout panel. Everything went well but the readings were imperfect so we had to do the
distribution error.
Our total angular for the loop traverse is 358°〖39〗^' 00'' and the total error angular is about 1°
〖21〗^' 00''. Therefore, it has 0°20'15'' error in angle for each angle.
Our error in latitude is -0.0194 and our error in departure is +0.0168. Thus, the total error is
0.0257. Using the following formula, we calculated the accuracy of our traverse survey:
Accuracy = 1: (P/EC), 1: [Perimeter/ Error Closure]
We obtained an accuracy of 1:3549. For average land surveying an accuracy of 1:3000 is
typical. Therefore, our traverse survey is acceptable.
In conclusion, we faced a lot of obstacles during the fieldwork. One of obstacles is we have to
ensure that the spirit bubbles have to be exactly at the centre point. We took a lot of time to set
up the theodolite at the first time because we have to make sure the spirit level is always in
middle in every position. Although the formula was really hard for us to apply compare to
levelling, but we try hard to learning with a spirit of not giving up.](https://image.slidesharecdn.com/fieldwork2-161208143210/85/Site-survey-Fieldwork-2-traversing-19-320.jpg)
Site survey Fieldwork 2 traversing
- 1. 1 SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN BACHELOR OF QUANTITY SURVEYING (HONOURS) [QSB 60203] SITE SURVEYING FIELDWORK 2 Traversing NAME STUDENT ID NG SHENG ZHE 0323830 SEW YUE LING 0327032 LIEU XUE QI 0327523 PHON KIT POI 0328435
- 2. 2 CONTENTS CONTENT PAGE NUMBER Cover page 1 Contents 2 Objectives 3 Introduction to Traversing 4-5 Apparatus Used for Traversing 6-7 Field Data 8-10 Adjusted Data 11-18 Summary 19 References 20
- 3. 3 Objectives ● To allow us to have a better understanding or knowledge about the process of using the instrument (Theodolite) rather than learning from a video in class. ● To enable us to have the experience in using theodolite such as setting up, collaborating, calculating and recording data. ● To allow us to have the teamwork while carrying out the fieldwork. ● To apply the theories that had learnt in class. ● To learn how to analyse the data collected. ● To enable us to have a basic knowledge on how to set up the points. ● To determine the error of misclosure in order whether is it acceptable or not in the traversing calculation. ● To enable us to know the precautions should be taken while using Theodolite. ● To allow us to experience and expose to the actual working environment in site such as working under the hot weather. ● To allow us to understand how to distribute different types of error from the data collected on field.
- 4. 4 Introduction to Traversing Traversing is a method of survey and establish and a method to carry out a survey plan. From the framework, the direction and length of the survey line must have a few of connected survey lines because it is provide help for the angle measure instrument. When the connected line formed a loop is called closed traverse, if the connected lines that did not formed a loop called open traverse. Two Types of Traverse 1) Closed Traverse 2) Open Traverse 1) Closed Traverse Closed traverses are used extensively in control, construction, property, and topographic surveys. The loop traverse starts and ends at the same points. To check a validity and accuracy of field measurements can use closed Traverses methods.
- 5. 5 2) Open Traverse A traverse whose end point is different from the starting point or is at an unknown position. Normally, Open Traverse is apply on underground surveys. In addition, repeated observation is required to minimize error.
- 6. 6 Apparatus Usedfor Traversing Theodolite A theodolite is an instrument for measuring angles in the horizontal and vertical planes. Theodolites are used mainly for surveying applications, and have been adapted for specialized purposes in fields like meteorology and rocket launch technology. Tripod A surveyor's tripod is a gadget used to support any one of a number of surveying instruments, such as theodolites, total stations, levels or transits. The surveyor will adjust on the legs'
- 7. 7 platforms to securely anchor the legs in soil or drive the feet to a low position on uneven, pock- marked pavement. Plumb Bob A plumb bob is a weight, at the bottom has a pointed tip that suspended from a string and used as a vertical reference line. Barcode Level Rod for Site Survey It is made by wood or steel. It is used to determine the height of different points.
- 8. 8 Field Data Station Field Angles A 89°06’00” B 89°27’40” C 89°05’40” D 90°59’40” SUM= 358°39’00”
- 9. 9 D = K x s x cos²(θ) + C x cos (θ) D = horizontal distance between survey point and instrument s = difference between top stadia and bottom stadia θ = vertical angle of telescope from the horizontal line when capturing the stadia readings K = multiplying constant given by the manufacturer of the theodolite, (normally = 100) C = additive factor given by the manufacturer of the theodolite, (normally = 0) Distance A-B = 100 x (1.493-1.324) x cos²( (90°−90°15′00") + (270°−269°43'20") 2 ) + ( 0 x cos( (90°−90°15′00") + (270°−269°43'20") 2 ) ) = 100 x 0.169 x cos²(0°00’50”) + 0 = 16.90 Distance B-A = 100 x (1.492-1.324) x cos²( (90°−89°17′00") + (270°−270°45'00") 2 ) + ( 0 x cos( (90°−89°17′00") + (270°−270°45'00") 2 ) ) = 100 x 0.168 x cos²(-0°01’00”) + 0 = 16.80 Average distance = (16.90 + 16.80)/2 = 16.85 Distance B-C = 100 x (1.560-1.269) x cos²( (90°−89°54’40”) + (270°−270°04’40”) 2 )+ ( 0 x cos( (90°−89°54’40”) + (270°−270°04’40”) 2 ) ) = 100 x 0.291 x cos²(0°00’20”) + 0 = 29.10 Distance C-B = 100 x (1.555-1.265) x cos²( (90°−89°41′40") + (270°−270°17'00") 2 )+ ( 0 x cos( (90°−89°41′40") + (270°−270°17'00") 2 ) ) = 100 x 0.290 x cos²(0°00’40”) + 0 = 29.00 Average distance = (29.10 + 29.00)/2 = 29.05
- 10. 10 Distance C-D = 100 x (1.492-1.327) x cos²( (90°−89°15′00") + (270°−270°45'00") 2 )+ ( 0 x cos( (90°−89°15′00") + (270°−270°45'00") 2 ) ) = 100 x 0.165 x cos²(0°) + 0 = 16.50 Distance D-C = 100 x (1.494-1.330) x cos²( (90°−89°56′20") + (270°−270°02'40") 2 )+ ( 0 x cos( (90°−89°56′20") + (270°−270°02'40") 2 ) ) = 100 x 0.164 x cos²(0°00’30”) + 0 = 16.40 Average distance = (16.50+16.40)/2 = 16.45 Distance D-A = 100 x (1.545-1.256) x cos²( (90°−89°39'20") + (270°−270°21'00") 2 )+ ( 0 x cos( (90°−89°39'20") + (270°−270°21'00") 2 )) = 100 x 0.289 x cos²(-0°00’10”) + 0 = 28.90 Distance A-D = 100 x (1.555 - 1.267) x cos²( (90°−90°02′20") + (270°−269°59'00") 2 )+ ( 0 x cos( (90°−90°02′20") + (270°−269°59'00") 2 ) ) = 100 x 0.288 x cos²(-0°00’40”) + 0 = 28.80 Average distance = (28.90 + 28.80)/2 = 28.85
- 11. 11 Angular Error & Angle Adjustments As known the sum of the interior angles in only loop traverse is equal to (n-2)(180°)for geometric consistency,therefore (4-2)(180°) = 2(180°) = 360 Total angular error = 360°00’00” - 358°39’00” = 1°21’00” Error per angle = 1°21’00”/4 = 0°20’15” Station Field Angles Corrections Adjusted Angles A 89°06′00" +0°20’15” 89°26’15” B 89°27’40” +0°20’15” 89°47’55” C 89°05’40” +0°20’15” 89°25’55” D 90°59′40" +0°20’15” 91°19’55” SUM= 358°39’00” 360°00’00”
- 12. 12 Computation for Course Azimuths Station Adjusted Angles Course Azimuths Course Bearing A-B 89°26’15” 89°26′15" N 89°26′15" E B-C 89°47’55” 89°26′15"+89°47’55”+180° =359°14’10” N 0°45’50” W C-D 89°25’55” 359°14’10”+89°25’55”-180° =268°40’05” S 88°40’05” W D-A 91°19’55” 268°40’05”+91°19’55”-180° =180°00’00” S 0°00’00” E
- 13. 13 Computation for Latitude and Departure Cos B Sin B L Cos B L Sin B Station Bearing,B Length,L Cosine Sine Latitude Departure A N 89°26’15”E 16.85 0.0098 0.9999 +0.1651 +16.8483 B N 0°45’50”W 29.05 0.9999 -0.0133 +29.0471 -0.3864 C S 88°40’05”W 16.45 -0.0232 -0.9997 -0.3816 -16.4451 D S 0°00’00” 28.85 -1.0000 0.0000 -28.8500 0.0000 A Perimeter(P)=91.20 Sum of latitudes=∑ΔY=-0.0194 Sum of departures=∑ΔX=+0.0168
- 14. 14 Correction = – [ ∑∆y ] / P x L or – [ ∑∆x ] / P x L Where, ∑∆y and ∑∆x = The error in latitude and departure P = Total length of perimeter of the traverse L = Length of a particular course Station Accuracy = 1: (P/Ec) Therefore, the accuracy = 1: (91.20/0.0257) = 1: 3548.6 = 1: 3549 For average land surveying, an accuracy of about 1:300 is typical. Thus, the accuracy of field is acceptable. A A’ Error in departure ∑∆𝑥 = +0.0168 𝑚 Error in latitude ∑∆𝑦 = −0.0194 𝑚 Ec, Total Error 91.20 m
- 15. 15 Adjusted Course Latitude & Departure The compass rule: Correction = -[y]P x L or - [x]P x L Latitude Correction The correction to the latitude: Course A-B is [-0.0194÷ 91.20] x 16.85 = -0.00358 Course B-C is [-0.0194÷ 91.20] x 29.05 = -0.00618 Course C-D is [-0.0194÷ 91.20] x 16.45 = -0.00350 Course D-A is [-0.0194÷ 91.20] x 28.85 = -0.00614 Departure Correction The correction to the departure: Course A-B is [0.0168÷ 91.20] x 16.85 = 0.00310 Course B-C is [0.0168÷ 91.20] x 29.05 =0.00535 Course C-D is [0.0168÷ 91.20] x 16.45 = 0.00303 Course D-A is [0.0168÷ 91.20] x 28.85 =0.00531
- 16. 16 Adjust Course Latitudes and Departures Unadjusted Corrections Adjusted Station Latitude Departure Latitude Departure Latitude Departure A + 0.1651 + 16.8483 0.0036 - 0.0031 + 0.1687 + 16.8452 B + 29.0471 - 0.3864 0.0062 -0.0054 + 29.0533 -0.3918 C -0.3816 -16.4451 0.0035 -0.0030 -0.3781 -16.4481 D -28.8500 0.0000 0.0061 -0.0053 -28.8439 -0.0053 A Check -0.0194 + 0.0168 0.0194 -0.0168 0.00 0.00
- 17. 17 Computation of Station Coordinates Assume that the coordinates of A is (100.000, 100.000) Station N Coordinate* Latitude E Coordinate* Departure A 100.000 (Assumed) 100.000 (Assumed) + 0.1687 + 16.8452 B 100.1687 116.8452 + 29.0533 -0.3918 C 129.2220 116.4534 -0.3718 -16.4481 D 128.8439 100.0053 -28.8439 -0.0053 A 100.000 (Checked) 100.000 (Checked)
- 18. 18 0 0 N 128.84 E 100.00 N 129.22 E 116.45 N 100.00 E 100.00 N 100.17 E 116.85 z D 100 110 120 130 z 120110100 A B C NORTH EAST
- 19. 19 Summary In this second fieldwork, we are required to do a closed loop traverse by using a theodolite at the carpark in Taylor’s University Lakeside Campus. The first thing we did is to set up the instrument and to mark four points for station which are station A, B, C and D. Before we took the measurement, we levelled the theodolite. First of all, we know that the point A, B, C and D are laid out on the site respectively. The theodolite is placed at station A which is our starting point and adjust it until it is in horizontal level. Besides, the other stations (A, B, C, D) must be stated on the site to form a loop traverse by using liquid ink. After that, we used theodolite to measure the angles of four stations as our field data. As we taught in class that the horizontal reading must be taken twice which is the first reading is taken, then turn back again to take the second reading. The angles of the theodolite must be read from left to right in order to obtain a more accurate reading. In order to obtain the angles form each point, the process is repeated at each of the points on the site. During the measurement, the vertical and horizontal angles will be shown on the digital readout panel. Everything went well but the readings were imperfect so we had to do the distribution error. Our total angular for the loop traverse is 358°〖39〗^' 00'' and the total error angular is about 1° 〖21〗^' 00''. Therefore, it has 0°20'15'' error in angle for each angle. Our error in latitude is -0.0194 and our error in departure is +0.0168. Thus, the total error is 0.0257. Using the following formula, we calculated the accuracy of our traverse survey: Accuracy = 1: (P/EC), 1: [Perimeter/ Error Closure] We obtained an accuracy of 1:3549. For average land surveying an accuracy of 1:3000 is typical. Therefore, our traverse survey is acceptable. In conclusion, we faced a lot of obstacles during the fieldwork. One of obstacles is we have to ensure that the spirit bubbles have to be exactly at the centre point. We took a lot of time to set up the theodolite at the first time because we have to make sure the spirit level is always in middle in every position. Although the formula was really hard for us to apply compare to levelling, but we try hard to learning with a spirit of not giving up.
- 20. 20 References http://surfcivil.blogspot.my/2010/05/traverse-surveying.html http://www.state.nj.us/transportation/eng/documents/survey/Chapter5.shtm Photo of group members: Phon Kit Poi Ng Sheng Zhe Sew Yue Ling Lieu Xue Qi