Survey-I-Practicals Final Form 21 Oct 2011

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LIST OF EXPERIMENTS

List Of Experiments of Survey I

Experiment No. 1: Measurement of Length by different Methods.

Experiment No. 2: Chain Traverse

Experiment No. 3: Topographic Survey (Using Chain & Tape) Experiment No. 4: Off-Set Survey.

Experiment No. 5: Measurement of Building.

Experiment No. 6: Compass Surveying.

Experiment No. 7: Study of Theodolite.

Experiment No. 8: Measurement of Height of the Building using the

Theodolite.

Experiment No. 9: Measurement of horizontal angles by repetition and

reiteration method with the theodolite.

Experiment No. 10: Study of Auto-Level.

Experiment No. 11: To determine Levelling Scheme with the Auto Level.

Experiment No. 12: Plane Table Surveying.

Experiment No. 13: Study of Total Station.

Experiment No. 14: Measurement of Distance using Total Station.

Experiment No. 15: Layout of different structures (Setting out).



Experiment#

Title Page no.

1. Measurement of length by pacing.2. Measurement of Building.3. Off-set Surveying.4. Compass Survey.5. Study of non-digital theodolite.6. Measurement of horizontal angles by

repetition and reiteration method with non-digital theodolite.

7. Traversing.8. Study of Tilting level.9. To determine leveling scheme with

tilting level.10. Plane tabling.



EXPERIMENT NO. 1. Measurement of Length by different Methods.

1. Measurement of length by pacing.

OBJECTIVE:

The main purpose of this experiment is to find the length with a humanpace. It is useful when rough estimates are needed and no instruments are present at

hand.

APPARATUS:

Measuring Tape,

R anging rods

PROCEDURE:

First mark a straight line of a standard length on a flat firm ground. Walk on the line

with normal footsteps and count the number of paces .R ecord three observation of

number of paces. Calculate the number of average paces by adding them and dividing by

three. Then calculate the standard pace by dividing the average pace with the total

length of tape.

Standard Pace = Total length of tape / Average Pacing

OBSERVATIONS AND CALCULATION:

Line StandardLength

Number of Paces Averagepacing

(ft)

StandardPace(ft)

Length b/w Stations by pacing

(ft)

1 2 3

ABBCCD

DE E A



Diagram of the closed traverse .

PRECAUTIONS:

1. Surface should be smooth and even.

2. Surveyor must walk in straight line.

3. Measuring tape must be kept straight and horizontal.

4. R anging should be performed for measurements grater than tape length.



EXPERIMENT NO. 5. Measurement of Height of the Building using the Theodolite.

OBJECTIVE:

The main purpose of this experiment is to measure the boundary of the

building.

APPARATUS:

Measuring Tape

PROCEDURE:

The steel tape is taken and two parties are made. One party stands at

the point from where measurement is started and the other party goes to the point up

till which measurement is required. The observation is made and the distance observed

is recorded, in this way whole of the building is measured and each length is recorded in

the copy. Then some scale is chosen to represent these measurements on the field book

and it is drawn on the field book like a plan.

(Picture of the plan)

PRECAUTIONS:

1. Measuring tape should be at the same level on both sides.

2. Measuring tape should be tightly used.

3. I f tape is used in the air then there should be minimum sag.



EXPERIMENT NO. 4 Off-Set Survey.

OBJECTIVE:

The main purpose of this experiment is to get familiar with the method of

off-set surveying which is a simple technique to show the information about the area.

APPARATUS:

Following apparatus are used in the practical,

i) Chainii) Tapeiii) R angingR ods

RELEVANT INFORMATION:

Offset surveying is the simplest method of surveying in

the field. Following terms are mostly used in this practical; there definitions are as

under,

CHA INING: It is a method of surveying, in which lengths of the sides of traverse are

calculated with the help of chain.

OFFSET: It is the lateral measurement taken from an object to the chain.

CHA IN A GE: Distance measured along the chain line up to the point from where we take

offset.

PROCEDURE:

It includes following steps,

a) First of all select the Station from where we have to start our survey. b) After selecting the station say A, also select the next station say B, fix the ranging

rod on both stations, so that both the stations are in line when seen from nakedeye.

c) Now lay down the chain from station A to station B.d) Now take offsets at various points with the help of chain and measure distance

from the object to the chain, also measure the change of each offset.e) R epeat this procedure for whole traverse.f) R ecord all these observations in the field book.

PRECAUTIONS:

1. Make sure that the tape is properly stretched and is free from any bending.



2. Check that the off-set distance recorded is the smallest (perpendicular) distance.

3. Check the chain line which should be straight.

4. The readings recorded should be of the same units .i.e either feet or meter.



EXPERIMENT NO.6 Compass Surveying.

OBJECTIVE:

The main purpose of this experiment is to know the other method of

surveying which is compass surveying. It is different from off-set surveying.

APPARATUS:

i) Prismatic compassii) Tripod stand on which Prismatic compass can be placediii) Metallic Chainiv) Metallic Tape v) R angingR ods vi) Plumb bob


The principle of compass surveying is traversing, which

involves a series of connected lines. The magnetic bearing of the lines are measured by

prismatic compass and the distances are measured with chain. Such survey does not

involve the formation of a network of triangles. Compass surveying is not recommended

for the areas where local attraction is suspected due to the presence of magnetic

substances like steel structures, iron, electric cables conveying current, e.t.c. For more

details refer to the book.

PROCEDURE:

The compass is fixed over the tripod stand and is centered over the station where

the bearing is to be found. This is done with the plumb bob.

Then the compass is properly levelled with the help of the bubble given on the compass.

Adjust the prism to view the readings correctly.

Then the compass is turned until the rod at the next station is bisected.

When the needle comes to rest look through the prism and note the reading .It will give

the required bearing.

R ecord this reading and accordingly repeat the same procedure for the whole traverse.

Stations without local attraction are founded and other readings are corrected in

accordance with these readings.




Line ObservedForeBearing

ObservedBack Bearing

Correction CorrectedForeBearing

CorrectedBack Bearing

R emarks

PRECAUTIONS:

1. Properly center and level the compass.

2. Observe the reading correctly on the compass.

3. Carry the compass carefully.

4. Observe the readings twice or thrice to make sure that they are free from any human

error.



EXPERIMENT NO. 11. To determine Levelling Scheme with the Auto Level.

OBJECTIVE:

The main purpose of this experiment is to find the reduced level of

different points using the tilting level.

APPARATUS:

Tilting level,

Tripod stand,

Measuring tape,

Hand level


The purpose of the hand level is to check that whether

the staff is truly vertical. The art of determining the relative heights of different points

on or below the surface of the earth is known as levelling. The vertical distance of a

point above or below the datum is known as the reduced level of that point. For further

details refer to the book.

PROCEDURE:

First of all staff is placed on the bench mark and hand level is used to

check its verticality. Then level is set up at any arbitrary point at some distance from thestaff say 100 ft. It is properly levelled. Then the staff reading is taken and recorded as

backsight in the book. The distance between the staff and the level is measured using the

tape. After wards the staff is shifted to the other point whose reduce level has to be

determined. This observation is called the foresight and any reading observed in

between the backsight and foresight is called the intermediate sight.In this manner the

level and staff are moved up till the required point, of which reduce level is to be

founded.




Station Backsight Intersight Foresight Height of instrument

R educelevel

R emarks

PRECAUTIONS:

1. Make sure that the staff is held vertical.

2. Check the level of the tilting level and make sure that it is not disturbed while

observing the reading.

3. Make sure that the readings observed are free form any parallax error.

4. The distance measured using the tape is accurate.

5. Check that the entries of B.S, I. S, F.S are correctly executed in the field book.



EXPERIMENT NO. 12. Plane Table Surveying.

OBJECTIVE:

The main purpose of this experiment is to know the purpose of plane table

and to be familiar with different methods of plane tabling.

APPARATUS:

i) The Plane Tableii) The Alidadeiii) The Spirit Leveliv) The Compass v) U-Fork or Plumbing Fork with Plumb Bob

There are four methods of plane table surveying, but the method we adopted in the field

is ³Traversing Method´.


The Principle of Plane tabling is parallelism, meaning

that the rays drawn from stations to objects on the paper are parallel to the lines from

the stations to the objects on the ground.

Plane tabling is a graphical method of surveying, hence, the field work and plotting are

done simultaneously and such survey does not involve use of field book.

PROCEDURE:

Following steps are included in procedure,

a) Suppose A, B, C and D are the traverse stations. b) The table is setup at station A.A suitable pointa is selected on the sheet in such a

way that the whole area may be plotted in the sheet. The table is centered, leveledand clamped. The North line is marked on the right hand top corner of the sheet.

c) With the alidade touching point a the ranging rod at B is bisected and a ray isdrawn. The distance AB is measured and plotted on a suitable scale.

d) The table is shifted and centered over B. It is then leveled, oriented by back

sighting and clamped.e) With the alidade touching the point b, the ranging rod at C is bisected and a ray isdrawn. The distance BC is measured and plotted on suitable scale.

f) The table is shifted and setup at C and the same procedure is repeated.g) In this manner all the stations of the traverse are connected.h) At the end, the finishing point may not coincide with the starting point and there

may be some closing error. The error is adjusted graphically by Bowditch¶s rule.



PRECAUTIONS:

1. Make sure that the table is properly levelled.

2. Mark the position of the station correctly and accurately with the alidade.

3. Fix the sheet properly on the table.



Experiment No. 8: Measurement of Height of the Building using the

Theodolite.

OBJECTIVE:

The objective of this experiment is to measure the height of the building using thetheodolite.

APPARATUS:

Theodolite

Tape


The height of the building is measured using the theodolite only. There comes occasions

when the top of the building or any structure is inaccessible. Then we use the theodolite

with the trigonometric technique to know the height of the building.

PROCEDURE:

1. Setup the theodolite at the point from where the top of building is visible.

2. Properly setup the instrument at that point.

3. Centre and Level it at the point.

4. Measure the HOI with the help of the tape.

5. Observe the vertical angle which the top of the building makes with the horizontal,

6. Draw the diagram of the triangle

7. By trigonometry, measure the height of the building.

SKETCH



PRECAUTIONS:

1. Make sure that the instrument is properly levelled.

2. Make sure that the instrument is not disturbed while observing the

reading.

3. Properly read the reading from the theodolite. Making sure that the

reading entered in the book is accurate.



Experiment No. 9: Measurement of horizontal angles by repetition and

reiteration method with the theodolite.

OBJECTIVE:

The objective of this experiment is to observe the horizontal angles using the theodolite by different methods.

APPARATUS:

i) Theodolite

ii) Tripod Stand

iii) R angingR od


Theodolite is used for measuring the horizontal angles and vertical angles accurately.The proper method of measuring the horizontal angle by theodolite is essential for every engineer. Repetition Method;

In this method, the angle is added several times mechanically and the value of the angleobtained by dividing the accumulated readings by the number of repetitions.

Reiteration Method;

It is another method of measuring of measuring the horizontal angle with more

precision and is preferred when several angles are to be measured at a station.In thismethod several angles are measured successively and finally the horizon is closed i.e. the

initial station is measured. The final reading of the leading vernier should be the same

as the initial reading. If not, the discrepancy is equally distributed among all the

measured angles.

PROCEDURE OF REPETITION METHOD:

1. Set up the instrument over µO¶ and level it accurately.2. With the help of upper clamp and tangent screw, set 0º reading on vernier µA¶.Notethe reading of vernier µB¶.

3. R elease the upper clamp and direct the telescope approximately towards the point µP¶.Tighten the lower clamp and bisect point µP¶ accurately by lower tangent screw.4. R elease the upper clamp and turn the instrument clock-wise towards Q. Clamp theupper clamp and bisect µQ¶ accurately with the upper tangent screw.Note the readings of verniers µA¶ and µB¶ to get the values of the angle POQ.5. R elease the lower clamp and turn the telescope clockwise to sight P again. Bisect P by using the lower tangent screw.



6. R elease the upper clamp, turn the telescope clockwise and sight Q. Bisect Q by usingthe upper tangent screw.7. R epeat the process until the angle measured (required number of times is 3). Theaverage angle with face left will be equal to final reading divided by three.8. Change face and make three more repetitions as described above. Find the average

angle with face right, by dividing the final reading by three.9. The average horizontal angle is then obtained by taking the average of the two angles with face left and face right.

PROCEDURE OF REITEREATION METHOD:

If it is required to measure angles AOB, BOC, and COD etc by reiteration method

The following steps are to be used.1. Set the instrument over ³O´ and level it set the Vernier to zero and bisect point A accurately.2. Loose the upper clamp and turn the Telescope clockwise to point B. Bisect B by usingthe upper tangent screw. R ead both the Verniers, the mean of the Verniers will give theangles AOB.3. Similarly, bisect successively C, D etc, thus closing the circle.R ead both the Verniersat any bisection.4. Finally sight to A the reading of the vernier should be the same as the original settingreading.R epeat the steps 02 to 04 with other face i.e. faceR ight.

PRECAUTIONS:

1. Your equipment must not cause an obstruction.

2. You must not put yourself or others in danger.3. Do not set up over loose materials or cables.4. Do not carry an instrument on a tripod.5. Keep all accessories within arms length.6. Do not leave equipment unattended.

Survey-I-Practicals Final Form 21 Oct 2011

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