Traversing- Tacheometry Report Group 7 PDF

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SCHOOL OF CIVIL ENGINEERING EAK GEOMATIC ENGINEERING TRAVERSING REPORT LECTURERS PROF. MADYA SR. DR. WAN MUHD AMINUDDIN WAN HUSSIN PROF. MADYA SR. DR. MOHD SANUSI S. AHMAD GROUP 7 GROUP MEMBERS NAME Aqilah binti Azhar Low Yan May Mok Tai Han Muhammad Hashim Habibie bin Arif Gusman Noorul Atikah bint...

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SCHOOL OF CIVIL ENGINEERING EAK 163/4 GEOMATIC ENGINEERING TRAVERSING REPORT LECTURERS PROF. MADYA SR. DR. WAN MUHD AMINUDDIN WAN HUSSIN PROF. MADYA SR. DR. MOHD SANUSI S. AHMAD

GROUP 7 GROUP MEMBERS NAME Aqilah binti Azhar Low Yan May Mok Tai Han Muhammad Hashim Habibie bin Arif Gusman Noorul Atikah binti Alias Nur Syazliana binti Abd Mokti

MATRICS NO. 137698 137734 137739 137743 137749 137758

LOCATION

: USM Engineering Campus Compound

DATE OF SURVEY

: 18th and 26th April 2018

1

INSTRUMENTS AND APPARATUS USED FOR TRAVERSING No

Instruments / Apparatus

Quantity

Serial Number and Brand

. 1. 2. 3. 4. 5. 6.

Total Station Tripod Prism Hammer Nails Spray Paint

1 3 2 1 6 1

4197 (Topcon) -

INTRODUCTION Traversing is a method of control surveying and is employed in all forms of legal, mapping and engineering surveys. Essentially, a traverse is a series of established stations tied together by angle and distance. The angles and the distances can be measured by using total stations, steel tapes or Electronic Distance- Measurement instruments (EDMs). And in this report, instead of using both theodolite and EDM to measure the angles and distance, we used total station which is integrated by both of the instrument and perform the task at once. Traverses can be open, as in route surveys, or closed, as in a closed geometric figure. The lines joining the stations in a traverse are known as the traverse lines. In short, traverse survey consists of the measurement of: i.

angles between successive lines (or bearings of each line), and

ii.

the length of each line.

There are several elementary methods available for traverse adjustment, but the one most commonly used is the compass rule which is called Bowditch method. The Compass Rule Adjustment is used in survey computations to distribute the error of closure proportionately between the different legs of the traverse. If done correctly the traverse will close precisely to the point of origin. There are two cases of closed traverse, close route traverse and close ring traverse. For the laboratory activities, we are used close ring traverse. It is a traverse starts from early station and will return at same point. This type of traverse is called polygon or loop. Also, the methods used in measuring angles or directions of traverse lines include interior angle method, deflection angles method and local attraction method.

PURPOSE OF TRAVERSING 2

Traversing is a convenient and rapid method for establishing horizontal control. It is very useful in densely built up areas and in heavily forested regions where lengths of sight are short. Traverses are made for numerous purposes, such as: i.

framework of surveys for housing or factory sites, or determination of the perimeters of lakes

ii.

original mapping and for the setting out of linear engineering works such as roads and railways

iii.

ground control surveys or photogrammetric mapping

iv.

supplementary horizontal control or topographic mapping surveys

v.

property surveys to locate or establish boundaries

Figure 1 : Total Station Equipment

3

OBJECTIVES Total station traversing is one of the methods to obtain horizontal control of surveying. We did traversing in order to supply one system of control points on a map or plan. When we need to plan a detail of construction, for example a site, the control points of traverse can be used to determine the middle point of a road, buildings etc. The following objectives can be achieved by doing total station traversing which is horizontal control of surveying: 

To learn to set up the total station precisely toward pointed point in working sector



To discover the uses and obtain readings of total station correctly



To be able to record the data into the table



To be able to transfer bearing for true North to our working sector



To measure internal angle of the working sector



To transfer the bearing on each pointed station in the working sector



To calculate the differences of angle theoretically and observe angle



To understand the misclosure classes while doing traversing using total station



To evaluate the misclosure and mean angle



To be able to do the correction on each pointed station



To compute coordinates of the traverse points.

OUTCOMES After we have done this theodolite traversing, we have accumulated some experience and all of us will be able to: 

Set up a total station and read horizontal angles



Improve our understanding and application of all theories that have been taught by lecturer



Understand the theoretical and analytical aspects of geomatics



Set up apparatus and carry out adjustment of a traverse instrument efficiently 4



Record the leveling data into the traversing form



Measure the internal angle and distance from one station to another station that have been established in our working sector.



Calculate the misclosure within the permissible limit

THEORY Traverse is a method in the field of surveying to establish control networks. Traverse networks involve placing survey stations along a line or path of travel, and then using the previously surveyed points as a base for observing the next point. Traversing is a measuring work of angle and distance of stations continuously and the final result is a loop of connected lines where we take the bearings and distances. There are two types of traversing which are open traverse and closed traverse. Open traverse: Open traverse is when the lines form a circuit which ends elsewhere but not the starting point. This method starts at any station without considering the coordinate and ends at an unknown coordinate. The ending station must not the starting station. Through this method, we can’t check or adjust all the data that we obtained.

Closed traverse: When the lines form a circuit which ends at the starting point, it is known as closed traverse. It is also known as loop traverse as the starting point and the ending point are the same.

TRAVERSE STATIONS A traverse station is any temporary or permanent point of reference over which the apparatus is set up . On roads, short roofing nails may be driven in and located by ties to nearby permanent features, while in fields, stout wooden pegs with small- headed nails driven in their tops are often favored. The stations should be chosen with the requirements of the survey in mind, aiming for good visibility between stations and bearing in mind any subsequent setting out. Areas liable to flooding and settlement are always suspected; remember that although a station position may be acceptable in so far as the lines of sight from adjacent stations are acceptable, the station itself will have to be occupied and should be suitable for both setting up the instrument, and for the surveyor to be able to read the angles(s) subtended there

HORIZONTAL DISTANCE Distance measurement is an important activity for most of the operations carried out by the surveyors. It is aim to establish the horizontal distance between two points, either by measuring between existing points or by setting a new point from an existing point. The word ‘horizontal’ is important. Other surveyed figures must be described in the horizontal distance between the points that establish the figure. Horizontal distances between two points at different elevations can be determined either by a procedure that allows the measuring device to be held horizontal or by directly measuring along a slope and computing horizontal distance from slope angles or from elevation differences.

BEARINGS The direction of any line with respect to a given meridian may be defined by the bearing. Bearings are called true bearings, magnetic bearings or assumed bearings that depending on whether the meridian is true, magnetic or assumed. The bearing of a line is indicated by the quadrant in which the line falls and the acute angle which the line makes with the meridian in that quadrant. The bearing of a line also gives the direction of 6

the line with respect to the reference meridian. The bearing states whether the angle is measured from the North or the South and also whether the angle is measured toward the east or toward the west.

TERMS AND DEFINITIONS

Term Vertical Axis

Definition The axis about which the instrument can be rotated in a

Horizontal Axis

horizontal plane The axis about which the telescope and vertical circle rotate in

Line of Sight

The line passing through the intersection of the horizontal and

(Trunion Axis) vertical plane. vertical cross hairs and the optical center of object glass and its Axis of Level Tube

continuation. The axis of level tube is a straight line tangential to the

Plumbing Centering Transiting

longitudinal curve of the level tube at its center. A plumb-bob is suspended centrally below the instrument The process of setting the theodolite exactly over the station. The process of turning the telescope in vertical plane through

Swinging the Telescope

180º about the trunion axis. The process of turning the telescope in a horizontal plane. - Telescope rotated clockwise ( swinging right ) - Telescope rotated counterclockwise ( swinging left )

Face left observation Face right observation Telescope Normal

If the face of the vertical circle is to the left of the observer. If the face of the vertical circle is to the right of the observer. A telescope is said to be normal when the face of the vertical

Telescope Inverted

circle is to the left. A telescope in said to be inverted when the face of the vertical

Changing the face

circle is to the right. The process of changing the face from left to right or vice versa.

Upper plate

(Transit and Swing ) The upper plate carries vernier scales 180º apart for reading the horizontal circle. 7

FIELD METHODOLOGY Setting up the tripod 1. Tripod legs was extend to a proper length. 2. The tripod was set approximately over the marked survey point. Setting up the Total Station 1. One tripod leg was fix into the ground. 2. The other two legs were to hold and move to roughly center the total station by locating the ground mark by plumb-bob. 3. The circular bubble can be leveled by adjusting the length of the one tripod leg at a time the other two still keep. 4. The total station was rotate until its plate bubble is centered for all positions. 5. The screw tripod was loosen and slowly translate the total station around until it is exactly centered the survey point. 6. Step (4) and (5) was repeated.

Measure horizontal angle 1. Loosen the vertical and horizontal clamps and use the peep sight on top of the instrument to locate the general direction of the prism. 2. Tighten both clamps. 3. Turn the focusing ring on the telescope until the image of the prism sharpens in the field of view. 4. Turn the vertical and horizontal fine motion screws to align the prism with the reticle. The last adjustment of each fine motion screw should be in the clockwise direction. 5. Step 1 to 4 is repeated on second prism. 6. Read and record the angle currently on display. This is the angle between the first and second station. 8

Measuring distances between stations: 1. Firstly, we set-up tripod at station 1 and install the instrument on the tripod. Then, we hang the plumbbob in the middle of the tripod, we make sure that the plumb-bob is pointing towards the point of the cross mark on the peg 1. 2. Then, we set-up a prism at station 2. As same the tripod hang a plumb-bob on the target. Make sure the plumb-bob point directly to the center of the peg. 3. Loosen the vertical and horizontal clamps and use the peep sight on top of the instrument to locate the general direction of the prism. Tighten both clamps. 4. Turn the focusing ring on the telescope until the image of the prism sharpens in the field of view. 5. Turn the vertical and horizontal fine motion screws to align the prism with the reticle. The last adjustment of each fine motion screw should be in the clockwise direction. 6. Select the distance measurement mode. 7. We go on with the same procedure until all five distances are taken.

9

RESULTS AND CALCULATIONS TOTAL STATION TRAVERSE ON WORKING SECTOR DATE LOCATION WEATHER

: 18th Apr 2018, 26th Apr 2018 : Around REDAC : SUNNY

3

BEARING / ANGLE FACE FACE MEAN LEFT RIGHT 289º00’00’’ 109º00’10’’ 105º22’20’’ 105º22’20’’ 285º22’20’’

1

289º00’00’’

109º00’00’’

3

105º22’20’’

285º22’20’’

2

285º22’20’’

105º22’20’’

STATION 1 2

2

DISTANCE (m)

1

30.926

2

3

22.417

2

1

30.926

3

22.417

2

22.417

4

8.298

3

8.298

5

35.416

4

35.416

6

29.886

5

29.886

7

31.519

6

31.519

1

32.162

7

32.162

2

30.926

2

105º22’16’’ 2 3

190º57’25’’ 4

190º57’25’’

10º57’25’’

3

10º57’25’’

190º57’25’’

4

190º57’16’’ 3 4

286º43’40’’ 5

286º43’40’’

106º43’35’’

4

106º43’40’’

286º43’40’’

5

286º43’27’’ 4 5

239º18’00’’ 6

239º18’00’’

59º18’00’’

5

59º18’00’’

239º18’00’’

6

239º17’43’’ 5 6

317º32’45’’ 7

317º32’45’’

137º32’45’’

6

137º32’45’’

317º32’45’’

7

317º32’23’ 6 7

79º17’05’’ 1

79º17 ’00’’

259º17’05’’

7

259º17’05’’

79º17’05’’

1

79º16’39’’ 7 1

109º00’40’’ 2

109º00’30’’

REMARKS

105º22’16’’

105º22’20’’

3

FINAL BEARING

STN

STN

109º00’10’

289º00’25’

1

10

2nd reading for the 1st station

11

Internal Angle of Traverse Calculation of Internal Angle of station: For example: To get internal angle for Station 2, Angle Station 2-1 (Face Left) – Angle Station 2-3 (Face Left) =internal angle for Station 2 Station 2 = 289°00’00’’- 105°22’20’’ = 183°37’40’’ By using this similar method, we can obtain all the internal angle at every stations. STATION 2 3 4 5 6 7 1

INTERNAL ANGLE 183°37’40’’ 94°25’55’’ 83°13’45’’ 227°25’40’’ 101°45’15’’ 58°15’45’’ 150°16’35’’

Calculation for misclosure No of the station, n = 7 Theoretical sum of internal angle

= (2n-4) x 90º = [(2 x 7) - 4] x 90 º = 900°00’00’’

Measured sum of internal angle = 183°37’40’’+ 94°25’55’’+ 83°13’45’’+ 227°25’40’’+ 101°45’15’’+ 58°15’45’’+ 150°16’35’’ = 899°59’35’’ Total of error

= 900º00’00’’- 899°59’35’’ = 00º00’25’’

Acceptable misclosure for 2nd class traversing = 30’’ x √n = 30’’ x √7 = 00º01’19’’ *The misclosure that we obtained from the practical is acceptable. Correction of internal angle : Correction per station =

Station

00° 00 ’ 25 ’ ’ 7

= 00º00’03’’/ 00°00’04’’

Internal Angle

Correction 12

Corrected Angle

2 3 4 5 6 7 1

183°37’40’’ 94°24’55’’ 84°13’45’’ 227°25’40’’ 101°45’15’’ 58°15’45’’ 150°16’35’’

04’’ 03’’ 04’’ 03’’ 04’’ 03’’ 04’’

183 °37’44’’ 94°24’58’’ 84°13’49’’ 227°25’43’’ 101°45’19’’ 58°15’48’’ 150°16’39’’

Calculation of bearings

WCB of Bearing 2-3 Ө3

= +

105°22’20’’ 94º24’58’’

199°47’18” WCB of Bearing 3-4 Ө4

= +

180°00’00” 19°47’18” 84º13’49’’

104°00’07” WCB of Bearing 4-5 Ө5

+ = +

180°00’00” 284°00’07”

WCB of Bearing 5-6 Ө6

= +

180°00’00” 331°26’50” 101°45’19”

227º25’43’’

511°26’50”

433°12’09” WCB of Bearing 6-7 Ө7

= +

180°00’00” 253°12’09” 58º 15’ 48’’

311°27’57” WCB of Bearing 7-1 Ө1

WCB of Bearing 1-2 Ө2 TABLE OF FINAL BEARING

WCB of Bearing 2-3 13

= + = + =

180°00’00” 131°27’57” 150º16’39’’

281°44’36” 180°00’00” 101°44’36” 183º37’44’’

285°22’20” 180°00’00” 105°22’20” [checked]

LINE

FINAL BEARING 105°22’20’’ 19°47’18’’ 284°00’07’’ 331°26’50’’ 253°12’09’’ 131°27’57’’ 101°44’36’’

2-3 3-4 4-5 5-6 6-7 7-1 1-2

LINE 3-2 4-3 5-4 6-5 7-6 1-7 2-1

BACK BEARING 285°22’20’’ 199°47’18’’ 104°00’07’’ 151°26’50’’ 73°12’09’’ 311°27’57’’ 281°44’36’’

CALCULATION Calculation of latitude and departure Latitude = distance x cos Ө (bearing) Departure =distance x sin Ө (bearing) Positive(+) North East

Latitude Departure

Station

Length(m)

WCB

2-3 3-4 4-5 5-6 6-7 7-1 1-2

22.417 8.298 35.416 29.886 31.519 32.162 30.926 190.624

105°22’20” 19°47’18” 284°00’07” 331°26’50” 253°12’09” 131°27’57” 101°44’36”

Total

Negative(-) South West

Latitude (m) North South 5.942 7.808 8.569 26.251 9.109 21.297 6.294 42.628 42.642 -0.014

Correction to the error of latitude and departure Total misclosure in latitude

= (42.628m – 42.642m) = -0.014m

Total misclosure in departure = (78.804m – 78.823m) = -0.019m 14

Departure (m) East West 21.615 2.809 34.364 14.285 30.174 24.101 30.279 78.804 78.823 -0.019

¿

Correction for latitude of any line

−(Length of Particular Distance)x (total misclosure∈latitude) ∑ Length

Correction for departure of any line ¿

−(Length of Particular Distance)x (total misclosure∈departure) ∑ Length

Calculation for linear misclosure. ΔL = -0.014m ΔD = -0.019m Closing error, e

=√ ΔL2 + ΔD2 = (-0.014) 2 + (-0.019) 2 = 2.360 x 10-2

Accuracy: Relative closing error = Closing error, e ∑ Length =

2.360 x 10−2 190.624

=1: 8076.998 ≈ 1: 8000 *The result is accepted.

Calculation for coordinates of stations Given that the coordinate of station 2 is (-29930.70N, 16412.96E). STATION

CORRECTION TO

CORRECTION TO 15

CORRECTED

CORRECTED

LATITUDE 2—3

(

)

22.417 ×0.014 190.624 ≈ 0.0016

3—4

8.298 ( 190.624 )×0...