Fundamentals of Drawings and Surveying

8/13/2019 Fundamentals of Drawings and Surveying

1/27

[FUNDAMENTALS OF DRAWINGS & SURVEYING]

1

TASK 04

(A) Dehiwala Municipal Council of Srilanka has decided to develop the road leading to

Frazer ground from Galle road. Assume you have been appointed as an officer in charge

of this development and required to submit a report after completing the following

activities.

I. Identify appropriated instruments and equipments for the above particular jobII. Set up, complete all temporary adjustment and use the appropriate instrument for

above typical surveying task

III. Explain the method of carrying out a leveling work.IV. Compute reduce levels and determine the errors in leveling.V. Plot the profile of existing road on longitudinal section to a scale of 1: 500 and 1: 100

(B) Dehiwala Municipal Council of Srilanka has decided to develop the Frazer ground.

Assume you have been appointed as an officer in charge of this development and required

to submit a report after completing the following activities

I. Identify appropriate instruments and equipments for the above particular jobII. Set up, complete all temporary adjustment and use the appropriate instrument for

above typical surveying task.

III. Explain the method of carrying out a traverse work.IV. Complete the coordinate sheet of it by taking the coordinates of the point A as

V. Plot the traverse and its details to a suitable scale on A3 sheet.VI. Determine the area of the plotted land and discuss its accuracy.

North East

1000 1500


2/27


3/27


3

TASK 04

A.

1. Identify appropriated instruments and equipments for the above particular job

There are different types of instruments are used in leveling. But, we can define some of

them. They are given below,

INSTRUMENTS

Tapes Compass

Ranging rods Plumb bob Tripod Leveling instrument Staff Field book Pen

Tapes

Tapes are mostly important for the leveling work. The following are the various types of

tapes

1. Cloth tape or Linen tape2. metallic Tape3. Steel tape4. Invar tape5. Synthetic Tape


4/27


4

Cloth tape or Linen tape

Our site we use this type of tape. It is made of varnished strip of woven linen 12 to 15

mm wide. It is available in lengths of 10m, 20m and 30m. It is very light and handy. It shrinks

when it is wet. It is likely to twist and tangle. So it is little used in surveying, but can be used

for taking subsidiary measurements such as offsets of a building.

Compass

It is like compass. It may consist of a level tube and a compass. It is using for different

purpose in different places. It is uses to level the tripod.

Plumb bob

Fig.4. Plumb bob

Plumb is a ball made of brass or bronze, of the shape of a pear. It has a fine steel point.

There is a hook at top for attaching a string of nylon. Its length is about 50mm. the plumb bob

is used for measuring distances on sloping ground. It is also used in the centering of various

instruments such as magnetic compass, plane table, Dumpy level or a theodolite etc.

Fig.2. Cloth Tape


5/27


5

Tripod

A surveyor's tripod with a shoulder strap. The head of the tripod supports the instrument

while the feet are spiked to anchor the tripod to the ground. A surveyor's tripod is a device

used to support any one of a number of surveying instruments, such as theodolites, total

stations levels or transits. Tripod is an important instrument in the surveying. Three legs are

available in tripod. Its three legs are fixed in a horizontal plate. We can increase or decrease

their legs. We can fix the telescope in horizontal plate.

Fig.5.Tripod

Ranging rods/ pole:

Ranging rods are used to marking a point in such a direction that the position of the

point. So, it is used to mark the measurement along the time. The length of the ranging rod is

either 2m or 3m.

They are shod at bottom with a heavy iron point. Ranging rods are divided into equal Parts

0.2m long and they are painted alternately black and white or red and white. When they are at

considerable distance, red and white or white and yellow flags about 25 cm square should be

fastened at the top

Fig.3. pole


6/27


6

Leveling Instrument:

Level is an instrument to take the vertical distance of points by obtaining the staff clearly. It

is also designed to give horizontal line of collimation.

Generally, level is two types. Namely,

Dumping level Tilting level

Fig.6.level

Telescope staff:

These are made of magohoney or metal. Staff lengths are 3m, 4m, or 5m, extension each

meter length of staff is divided into 200 divisions of each 5mm.

There are different types of staffs are used in leveling. They are usually made of rigid

fiberglass. The most common staffs are graduated in meters, decimeters, and centimeters. The

two most common types of staff faces are the E typeface or the 5mm graduated face. The

staff should be held vertical over the point to be measured with the face of the staff pointingtowards the level.

Fig.7. leveling staffs


7/27


7

2. Set up, complete all temporary adjustment and use the appropriate instrument for

above typical surveying task

1. Position the tripod. Place the instrument on a stable surface in a position where you can

see all the levels to be taken. Try to position the instrument evenly between the points

you need to sight. It is important to make sure you have a clear line of sight.

Fig.8.Tripod

2. Adjust the tripod. Make sure that the tripod legs are spread evenly and the platform

where the instrument will sit is fairly level. Adjust the tripod to suit your own height, then

tighten the clamps. Remember not to use excessive force on the screws and clamps.

Fig.9.

3. Attach the leveling instrument. Lift the instrument using both hands and place it on the

tripod. Keep the instrument stable with one hand while you use the other to tighten the

retaining screw in between the legs. Only when the retaining screw is tightened can you

release your grip on the instrument.Make sure the instrument is

securely fixed.

Fig.10. level

4. Adjust for parallax. Because people's eyesight varies, you may have to adjust the

instrument so it will enable you to take accurate readings. If you find that when you look


8/27


9/27


9

2. Zoom in: look through the eyepiece and zoom in on the staff by turning the

focusing knobs on the side of the telescope until you can read the marks clearly.

Fig.14.Staff


10/27


10

3. Explain the method of carrying out a leveling work.

Step-By-Step Instructions for Leveling a Staff Gage

Leveling a staff gage requires several steps.

1. Find a Bench Mark (or Reference mark) which will be your starting elevation.

2. Convert this elevation to elevation above Gage Datum if necessary.

3. Ready your equipment (level, tripod, and rod).

4. Pick an initial placement for the tripod and level.

5. Level the instrument on top of the tripod.

6. Look through the instrument and take Backsight reading.

7. Calculate the Height of Instrument (HI).

8. Have person with rod move to next location (Temporary Bench Mark) and take a Foresight

reading.

9. Calculate the elevation of the ground at a second location known as a Temporary

BenchMark (TBM2).

10. Repeat steps 3 - 8 as necessary until you reach the desired location of the staff gage.

11. Set Staff Gage.

12. Recheck Elevations.


11/27


11

4. Compute reduces levels and determines the errors in leveling.

Station B.S IS F.S H.I R.L Distance

B.M 1.170 101.170 100.000

1 1.400 99.770 0

2 1.315 99.855 10

3 1.410 99.760 20

4 1.367 99.803 30

T.P 1 1.393 1.224 101.339 99.946

5 1.393 99.946 40

6 1.380 99.959 50

7 1.483 99.856 60

8 1.580 99.759 70

9 1.621 99.718 77.54

T.P 2 1.100 1.380 101.059 99.959

1.041 100.018

Check 3.663 3.645 100.000

3.663 100.018

Rise (- 0.018) Rise (- 0.018)

Table No 1


12/27


12


13/27


13

B.

1. Identify appropriate instruments and equipments for the above particular job

There are different types of instruments are used in traverse. But, we can define some of

them. They are given below, Some instruments details are given for leveling work.

INSTRUMENTS

Tapes Compass Arrows Ranging rods Pegs Plumb bob Tripod Theodolite Field book Pen

Tapes

Tapes are mostly important for the leveling work. The following are the various types of

tapes

1. Cloth tape or Linen tape2. metallic Tape3. Steel tape4. Invar tape5. Synthetic Tape

Fig.1. Tapes


14/27


14

Compass

It is like compass. It may consist of a level tube and a compass. It is using for different

purpose in different places. It is uses to level the tripod.

Arrows

It is used to mark the end of the each chain during the chaining process. Arrows are

made of good quality hardened steel wire of 4 mm diameter The arrows are made 400 mm

in length, are pointed at one and the other end is bent into a loop or circle. Here this particular

traverse practical, we used the arrow is in replaced the peg.

Fig.15. Arrows

Pegs

It is made of hard wood and is 2.5 cm square in cross-section and 150 mm long. It is

tapered at other and to facilitate easy driving. It is used to mark the position of the survey

station or end points of a survey line. The pegs are driven into the ground using a mallet or

wooden hammer such that its length of about 40 mm project above the surface of the ground.

Fig.16.Peg


15/27


15

Theodolite

A theodolite is an instrument for measuring both horizontal and vertical angles, as

used in triangulation networks. It is a key tool in surveying and engineering work, but

theodolites have been adapted for other specialized purposes in fields like meteorology and

rocket launch technology. A modern theodolite consists of a telescope mounted movably

within two perpendicular axes, the horizontal or turn-on axis, and the vertical axis. When the

telescope is pointed at a desired object, the angle of each of these axes can be measured with

great precision, typically on the scale of arc seconds.

Fig.17.Theodolite

Plumb bob

Fig.4. Plumb bob

Plumb is a ball made of brass or bronze, of the shape of a pear. It has a fine steel point. There

is a hook at top for attaching a string of nylon. Its length is about 50mm. the plumb bob is


16/27


16

used for measuring distances on sloping ground. It is also used in the centering of various

instruments such as magnetic compass, plane table, Dumpy level or a theodolite etc.

Tripod

A surveyor's tripod with a shoulder strap. The head of the tripod supports the instrument

while the feet are spiked to anchor the tripod to the ground. A surveyor's tripod is a device

used to support any one of a number of surveying instruments, such as theodolites, total

stations levels or transits. Tripod is an important instrument in the surveying. Three legs are

available in tripod. Its three legs are fixed in a horizontal plate. We can increase or decrease

their legs. We can fix the telescope in horizontal plate.

Fig.5.Tripod

Leveling Instrument:

Level is an instrument to take the vertical distance of points by obtaining the staff clearly. It

is also designed to give horizontal line of collimation.

Generally, level is two types. Namely,

Dumping level Tilting level

Fig.6.level


17/27


17

Telescope staff:

These are made of magohoney or metal. Staff lengths are 3m, 4m, or 5m, extension each

meter length of staff is divided into 200 divisions of each 5mm.

There are different types of staffs are used in leveling. They are usually made of rigid

fiberglass. The most common staffs are graduated in meters, decimeters, and centimeters. The

two most common types of staff faces are the E typeface or the 5mm graduated face. The

staff should be held vertical over the point to be measured with the face of the staff pointing

towards the level.

Fig.7. leveling staffs


18/27


18

2. Set up, complete all temporary adjustment and use the appropriate instrument for

above typical surveying task.

1. Open the legs of the tri pot & adjust the length of them about that the instrument whenfitted will be at a convention type clamp the legs & by estimation set up the tri pot

over the station.

2. Remove the Theodolite from its box noting how it was fitted bolt is centrally on thetri pot head & set the foot screw to the middle of their travel.

3. Tread & tri pot foot in to the ground & looking through the optical planet poison theother two legs show that the station appears central, thread in the other two feet on a

hard smooth surface the tri pot feet must be prevented from sliding out words bricks

or concrete blocks and be placed against them.

4. If the station appears longer central in the plummet turn the foot screw until itreappears central.

5. Mark the instrument level by shortening or lengthening of tri pot legs check with thebulls eye bubble is fitted other wise set the plate bubble parallel to the line between

two leg shortening or lengthening them to centre the bubble, turn the validate through

90 & re centre the bubble by adjusting the tri pot legs.

Repeat this process until the bubble is with in two division of central site through

the optical plummet if the instrument is not its still approximately re centre it by

relax the securing bolt (clamp)sliding the Theodolite horizontally & tittering the

clamp or bolt.

6. Finally level the Theodolite using the foot screws set up the plate bubble parallel tothe line through two foot screws and turn these screws in opposite to bring the bubble

central, turn the alidade through 90 & re centre the bubble using the third food screw

return the bubble to its original position & repeat the procedure until the bubble

remain central in both position the bubble follows the moment of the left thumb.

If the bubble is correctly set in its mountain it will remain central but ever its

disposition this may be check by turning the alidade through 180 from the 1stposition

if the bubble moves off center it should be brought have way back with the foot

screws & further adjustment made (with all foot screws) show that the bubble remain

in this position.


19/27


19

Fig shows the plate with the bubble in its various position

Fig.18. Adjustment

7. Precisely central the Theodolite loosen the loosen the clamp or bolt and care fullyslide the instrument site ways till the station appears central in the optial plummet,

where central use is below the foot screw take care or instrument or leveling will be

disturb tighten or the bold of clamp

8. Repeat step 6 & 7 until the Theodolite remain level & centre

9. Sitting a plane back ground rotate the eye piece to focus the cross hair or target


20/27


20

3. Explain the method of carrying out a traverse surveying

Traverse field work may be described by a series of steps as follows:

1. Choose positions for stations as close as possible.2. Mark the stations by stakes with tacks or stone or concrete monuments set flush with

the ground, with a precise point marked on the top by a chiseled cross, drilled hole, or

bronze tablet.

3. Adjust the theodolite Turn the leveling screws in opposite directions until mercury bubble comes

middle of circle

Turn the theodolite to 90 degrees and level the theodolite4. Make angle and length measurements.5. Place signals at each stations

A range pole stuck in the ground can be used for taping. A range pole carefully balanced and held on the point is used for measuring

angles.

For a short course, a plumb bob can be held over the point, or a pencil can be

balanced on the point for angle measurement.

Traverse surveying method

Drawing a recognition diagram.To get a basic idea we use recognition diagram. Here we identify the important

points and draw a temporary diagram.

Identify the survey stations.(a)We identify at four inter visible points.(b)Adjoin points should be inter visible.(c)Mark the points with pegs(d)Label the pegs

Group or survey number (use identical color)

Station number (mark clock wise)

(e)Mark points on recognition diagram


21/27


21

Take tie measurement.(a)Two points enough for measurement we get the third point for checking

purpose.

(b)The point should be marked before measurements in trees and walls Take the offset.

Select base line (line with maximum length)

Offsettake the minimum distance from the main line.

Details should be included in the drawing.

Offsets.1) Perpendicular Possibility distance 5 m

Recordings

, chain age, offset

Measuring the perpendicularity.

2) Oblique offsetsTake two readings

Side offset

P2

L.H. R.H.

P1

` Measure distances of checking lines.


22/27


22

1. Systematic errorserrors in instrument, theory behind the practical work.Example reading can be varying due to the temperature.

Difference between our tape and slandered tape.

These types of errors can be ignored.

2. Accidental error

Incorrect reading of tape - we use proper tape Incorrect plumbing - we plumb correctly Wind blowing against the tape - dont use tapes during wind3. Mistakes

Misreading the number - check more than one time Recording numbers incorrectly - recode more than one time Using wrong zero position - check more than one time Omitting the tape length - make sure not omitted

Tape can be touch with other object. - make sure not touched


23/27


23

4. Complete the coordinate sheet of it by taking the coordinates of the point A as

Station Angles Length (m)

ND 189 52' 40"

A 87 44' 20" AB65.06

B 92 41' 20" BC61.44

C 82 27' 40" CD65.96

D 97 14' 00" DA55.80

Total 360 07' 20" 248.26

Table No 01

Total Error = 360 07' 20" - 360

= 00 07' 20"

= 00 07' 20'/4

= 00 01' 50"

Correction of Angular Error

Point Angle Error CorrectedAngle

A 87 44' 20" 00 01' 50" 87 42' 30"

B 92 41' 20" 00 01' 50" 92 39' 30"

C 82 27' 40" 00 01' 50" 82 25' 50"

D 97 14' 00" 00 01' 50" 97 12' 10"

Total 360 07' 20" 00 07' 20" 360 00' 00"

Table No 2


24/27


24

WHOLE CIRCLE BEARING

WCBwhole circle bearing

WCB of AB = 189 52' 40" + 87 42' 30"

= 27735' 10

WCB of BC = 27735' 10 + 92 30' 30" + 180'

= 550 14' 40"

Deduct = 360 if answer is more than 360

= 550 14' 40" - 360

= 190 14' 40

WCB of CD = 190 14' 40" + 82 25' 50" + 180

= 452 40' 30" - 360

= 92 08' 30"

WCB of DA = 92 40' 30" + 97 12' 10" + 180

= 369 52' 40" - 360

= 9 52' 40"

Station Corrected angle Line WCB

ND 189 52' 40"

A 87 42' 30" AB 277 35' 10"

B 92 39' 30" BC 190 14' 40"

C 82 25' 50" CD 92 40' 30"

D 97 12' 10" DA 09 52' 40"Table No 03


25/27


25

latitude and departures computation

Latitude = LCos

L = length(m)

= whole circle bearing

Latitude AB = L Cos

= 65.06 Cos 277 35' 10"

= 8.58

Line BC

Latitude BC = L Cos

= 61.44 Cos 190 14' 40"

= - 60.46

Line CD

Latitude CD = L Cos

= 65.96 Cos 9240' 30"

= -3.07

Line DA

DA Latitude = L Cos

= 55.80 Cos 9 52' 40"

= 54.97


26/27


26

Line WCB Length Latitude

AB 277 35' 10" 65.06 8.58

BC 190 14' 40" 61.44 -60.46

CD 92 40' 30" 65.96 -3.07

DA 9 52' 40" 55.80 54.97

Total 248.26 0.02Table No 04

DA Departure = L Sin

L = Length(m)

= Whole circle bearing

Departure AB = LSin

= 65.44 Sin 27735'10"

= -64.49

Departure BC = LSin

= 61.44 Sin 190 4' 40"

= -10.93

Departure CD = LSin

= 65.965 Sin 92 40' 30"

= 65.89

Departure DA = LSin

= 55.80 Sin 9 52' 40"

= 9.57

Line WCB Length (M) Latitude

AB 277 35' 10" 65.06 -64.49

BC 190 14' 40" 61.44 -10.93

CD 92 40' 30" 65.96 65.89

DA 9 52' 40" 55.80 9.57

Total 248.26 0.04

Table No 05


27/27


Total Error = ((0.02)2+ (0.04)2)1/2

= 0.04

Line WCB Length Latitude Error Corrected

latitude

AB 277 35' 10" 65.06 8.58 -0.01 8.57

BC 190 14' 40" 61.44 -60.46 0.00 -60.46

CD 92 40' 30" 65.96 -3.07 -0.01 -3.08

DA 09 52' 40" 55.80 54.97 -0.00 54.97

Total 248.26 0.02 -0.02 00.00

Table No 06

Line WCB Length Departure Error Correctedlatitude

AB 277 35' 10" 65.06 -64.49 -0.01 8.57

BC 190 14' 40" 61.44 -10.93 -0.01 -60.46

CD 92 40' 30" 65.96 65.89 -0.01 -3.08

DA 09 52' 40" 55.80 9.57 -0.01 54.97

Total 248.26 0.04 -0.04 00.00

Table No 07

Station latitude Departure North EastA 1000 1500

B 8.57 -64.50 1008.57 1435.5

C -60.46 -10.94 948.11 1424.56

B -3.08 65.88 945.03 1490.44

A 54.97 9.56 1000 1500

Table No 08

Documents

Fundamentals of Drawings and Surveying