Surveying Observation, surveying, observation

7/23/2019 Surveying Observation, surveying, observation

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Prepared by Er.JEBASTIN THANASEKAR J Page 1

WE TRUST IN GOD

ARALVAIMOZHI-629 301. KANYAKUMARI DIST.,

For second year civil engineering,


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ARALVAIMOZHI-629 301.

KANYAKUMARI DIST.,TAMILNADU

WE TRUST IN GOD

PRACTICAL MANUAL

Name of the Student : ..

Register Number :.

Class :.


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CONTENT

SI.NO Date Name of the ExperimentPage

No.


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SYLLABUS

CE1205 SURVEY PRACTICAL I 0 0 4 100

OBJECTIVE

At the end of the course the student will posses knowledge about Survey field techniques

1. Study of chains and its accessories2. Aligning, Ranging and Chaining3. Chain Traversing4. Compass Traversing5. Plane table surveying: Radiation6. Plane table surveying: Intersection

7. Plane table surveying: Traversing8. Plane table surveying: Resection Three point problem

9. Plane table surveying: Resection Two point problem10. Study of levels and levelling staff

11. Fly levelling using Dumpy level12. Fly levelling using tilting level

13. Check levelling14. LS and CS

15. ContouringTOTAL : 60


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Ex No: 1 Date:

STUDY OF CHAINS AND ITS ACCESSORIES

CHAIN:

The chains are made up of steel which is in length of 20 m or 30 m.

Used for measuring the linear dimensions.

Chain is the ancient time measuring instrument.

Small brass rings are provided for every one meter length.

Brass tallies are fixed at a every 5m length.

It is composed of 100 or 150 pieces of galvanized mild steel wire 4mm in dia called

links.

The length of each link is 20cm.

The ends of chain are provided with brass handles.

Types of chains

1. Metric chain.

2. Gunters chain (or) surveyors chain.

3. Engineers chain.

4. Revenue chain.

5.

Steel band (or) band chain.

RANGING RODS:

Ranging rods are made up with hollow iron steel at a the length of 2m or 3m.

The cross section is circular.

Alternate black & white or red & white bands of 20cm length are painted in the

ranging rod to be visible at long distance.

To ranging or straightening the line the ranging rod must only be used. To mark the points on the ground to be visible with our eyes & instruments.

Bottom of the ranging rod must be sharp iron shoe & top must be hollow in

circular.


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ARROWS:

Arrows are made up of steel wire.

It is 4mm dia & 40cm length.

Arrow are pointed at one end for inserting to the ground & bend at

other end for facility of carrying.

In the time of chaining the changing of chain arrows are used.

The top of the portion is hooked.

PEGS:

o This is also for same purposes as that of arrows.

o It is made up of wood or steel.

o It is of diameter is 2cm to 3 cm & length of 40cm to 60cm.

o It is straight & circular in shape. The bottom of peg has sharp shoe.

CROSS STAFF:

This consists of wooden block with two fine saw cuts at right angles to each other on

the top.

Main purpose is to set the right angle for marking of building in the ground.

The head is fixed at iron rod with other end pointed to drive into the ground.

Now a-days the top of the wooden block is advanced of with iron material having

two horse hairs & eye slits.

TAPE:

It is the advanced material for measuring linear dimensions

It is made up of the fiber wired plastic material or steel or cloth.

It has various lengths of 3m, 5m, 10m, 20m, 30m, 60m, etc.

It will get expanded or shortened due to the temperature compared to the chain.

It gives the most accurate value compared to the chain.


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Types of tape

1. Cloth (or) linen tape.

2. Metallic tape.

3. Steel tape.

4.

Invar tape.

PLUMB BOB

It is a material used for checking out the verticality and marking the specific centrepoint accurately.

It is a most important material for the site. It is in cone shape and tied with a thread for a needed length.

RESULT:

The Details of all surveying instruments as connected with chain surveying mentioned

above have been learnt properly.


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Figure:

Direct ranging

- - - - - - - Chain line

- Station

- Tie Station

- Chain line


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Ex No: 2 Date:

ALIGNING, RANGING AND CHAININGAIM:

To determine the distance between two inter-visible ends of the survey line using direct

ranging.

INSTRUMENTS USED:

Chain

Ranging rods

Arrows

Cross staff

THEORY:

Two men are required for chaining operation. The chain man at the forward end of chain

is called the leader while the other man at the rear end is known as the follower.

Duties of leader &follower

Leader:-

1) To put the chain forward

2) To fix arrows at the end of chain

3) To follow the instruction of the followers.

Follower:-

1) To direct the leader to the line with the ranging rod.

2) To carry the rear end of the chain.

3) To pick up the arrows inserted by the leader.

PROCEDURE:

Let A and B be the two end points of a survey line.

Erect one ranging rod at point B while the surveyor stands with another ranging rod at

point A at about half a meter length.

The assistant goes with another ranging rod and establishes the rod at a pointapproximately in the line with AB at a distance not greater than one chain length from A.

The surveyor at A point signals the assistant to move transverse to the chain line.

Similarly other intermediate points can be established.

After taking the number of intermediate points the chain can be stretched exactly on the

survey line AB touching the intermediate point.


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Ex No: 3 Date:

CHAIN TRAVERSING(Area Calculation)

AIM:

To determine the area by using triangular method.

INSTRUMENTS USED:

1. Tape

2. Chain

3. Arrows

4. Ranging rods

THEORY:

Cross-Staff is the simplest instrument used for setting out perpendicular i.e. taking offsets from a

chain line. It is easier and quicker method, but not very accurate .If great accuracy is desired,the work should be carried out by the theodolite.

Open cross staff:- The simplest Type consists two parts

1. The head

2. The leg

The head is made of wooden block octagonal or round in shape about 15cm side or diameter

and 4cm deep. On it two lines are scribed at right angles to one another. At the end of these two

lines two points of metallic strip are fixed having slits made in them .These two lines of sight

are at right angles to one another .The head is fixed on a wooden staff or pole about 3cm indiameter and 1.2 to 1.5m length .The pole is provided with a conical metal shoe so that it

can be driven into the ground.

PROCEDURE:

Let ABCDEF are the points selected on given plot for which the area is to be measured.

Arrows are fixed at the points A, B, C, E, D and F along the boundary of the given plot

there by making closed traverse.

Select a point approximately at the center of the given plot.

Then consider the plot into no. of triangles such as AOB, COD and so on.

Measure the length of AB, BC, CD, DE, and EF etc. Also measure the length of OA,

OB, OC, OD, OE, OF etc.

FORMULAUSED:

The area A=s(s-a)(s-b)(s-c)

Total area will be the sum of all i.e. A=A1+A2+A3+A4+.An


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Where

= + +2

a, b, c being the sides of triangles

F

O

RESULT:

Area of the plot by using triangular method is done

Area of the given plot= _________________

A

B

C

D

E


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Ex No: 4 Date:

AREA CALCULATION BY PERPENDICULAR OFFSET METHOD

AIM:

To determine the area of the given plot by perpendicular offset method.

INSTRUMENTS USED:

Chain

Ranging rod

Arrow

Cross staff

TapeTHEORY

. The object of cross staff survey is to locate the boundaries of field or plot and to find out

its area.

In this method a base line in the centre of the area is selected. Chaining along this line is

done and the offsets of the points lying on the boundaries of the plot are taken at different

chainages by using a cross staff and tape on either side of the chain line and recorded

against the chainages in the field note book as already discussed .The offsets length are

written on the left hand side or right hand side of the line as per their position until whole of the

area is surveyed. The plot is then divided into triangles and trapezoids because it is easy to find

out the area of triangle and a trapezoids.

The area of the field is computed by the following formulae.

(1) The area of a right angle triangle is equal to the base multiplied by half the perpendicular

(2)The area of a trapezoid is equal to the base multiplied by half the sum of the Perpendicular.

PROCEDURE:

Let A, B, C, D etc are the point which are selected along the boundary of

the plot for which the area is to be measured.

Now fix the ranging rod at any two selected point approximately to the

nodes of the side.

Hold the cross staff until the line GC is fixed perpendicular to chain line.

Measure the distance from the chain at site

Finally the area is calculated by dividing the entire area into a number of

triangles and trapezoids by taking the offset.

Area of triangle A = 1/2 bh

Area of trapezoid = [1/2 (a+b)]h


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Proposed plan:

A

C G

H E

D IF

J

B

RESULT:

Thearea computed by using the perpendicular offset =in square meter


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Ex No: 5 Date:

COMPASS TRAVERSE

AIM:

To find out included angle for a closed compass traverse ABCD using prismaticcompass.

INSTRUMENTS REQUIRED:

o Prismatic compasso Arrowso Ranging rod

THEORY:

Adjustment of the Prismatic Compass

The compass may be held in hand, but for better results it should be fitted at the top of

tripod having ball and socket arrangement. The adjustment of a compass is done in the following

three steps.

1) Centering: - The compass fitted over the tripod is lifted bodily and placed approximately on

the station peg by spreading the leg of a tripod equally, The centre of the compass is checked by

dropping a small piece of stone from the centre of the bottom of the compass so that it

falls on the top of the station peg. A plumb bob may be used to judge the centering either by

attaching it with a hook provided at the bottom or otherwise by holding it by hand.

2) Levelling:-After the compass is centered, it is leveled by means of ball and socketarrangement so that the graduated circle may swing freely. It can be checked roughly by placing

a round pencil on the top of the compass. When the pencil does not move, it is roughly in the

horizontal position.

3) Focusing the prism: - The prism attached is moved up and down so that graduation on the

graduated circle should become sharp and clear

PROCEDURE:

Select the point A, B, C, D and E along the boundary at the traverse. Set the prismatic

compass at the station A and level is accurately

Take the fore bearing AB from the true north in clock wise direction. From the same

point A take back bearing AE in the clock wise direction from the line north at A.

Now shift the compass from A to B and do all the adjustments. Take the fore bearing of

line BC and the back bearing of the line BA.


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The mirror angle A is calculated as angle in BB of previous line-FB of next line. The

included angles A, B, C, D and E are calculated.

The sum of all included angle = (2n-4)900

Where n is number of sides.

A

B

1

4

23

D

C

RESULT:The interior angle observed using the compass =.Distance between the points calculated as=..


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each rod and reads the value. Subtracting the "back" and "forward" value provides the height

difference.

We can't expect the instrument to be in perfect adjustment, but we can hope that when the

bubble is centered the telescope's line of sight is always the same small angle off of horizontal.

If it is, we can still level accurately by setting the instrument exactly midway between the points

to be measured, so the errors cancel.

Leveling Procedure

A typical procedure is to set up the instrument within 100 meters (100 yards) of a point of

known or assumed elevation. A rod or staff is held vertical on that point and the instrument is

used manually or automatically to read the rod scale. This gives the height of the instrument

above the starting (backsight) point and allows the height of the instrument (H.I.) above the

datum to be computed.

The rod is then held on an unknown point and a reading is taken in the same manner, allowing

the elevation of the new (foresight) point to be computed. The procedure is repeated until thedestination point is reached. It is usual practice to perform either a complete loop back to the

starting point or else close the traverse on a second point whose elevation is already known. The

closure check guards against blunders in the operation, and allows residual error to be

distributed in the most likely manner among the stations.

Some instruments provide three crosshairs which allow stadia measurement of the foresight and

back sight distances. These also allow use of the average of the three readings (3-wire leveling)

as a check against blunders and for averaging out the error of interpolation between marks on the

rod scale.

The two main types of levelling are single-levelling as already described, and double-levelling

(Double-Roding). In double-levelling, a surveyor takes two foresights and two back sights and

makes sure the difference between the foresights and the difference between the back sights are

equal, thereby reducing the amount of error. Double-levelling costs twice as much as single-

levelling.

LEVELING EQUIPMENT

TYPES OF LEVELING EQUIPMENT

Hand Levels

Abney Levels Automatic Levels

Laser Levels

Dumpy Levels


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HAND LEVELS

A hand held instrument.

Low precision work or for checking purposes.

ABNEY LEVELS

A type of hand level.

Includes a clinometer for measuring vertical angles.

AUTOMATIC LEVELS

Incorporate a self leveling feature.

Popular for general use.

Easy to set up and use.

Rough leveling is done by adjusting the leveling screws, then the self-leveling feature

takes over to completely level the telescope.

LASER LEVELS

Used in construction surveys to create a visible line of known orientation and elevation

from which measurements for line and grade can be made.

Give accurate readings at distances of 1000 ft.

Can provide control elevations over a 1,000,000 square foot area from a single setup.

DUMPY LEVELS

Standard equipment before automatic levels were available.

The telescopic sight must be completely leveled manually by adjusting the leveling

screws.

COMMON CONCEPTS

All leveling equipment have the following in common:

Telescope

Level Vials and

Level Rods

LEVEL VIALS

Level vials are a means of setting up an instrument to be horizontal or vertical.

They can either be bulls-eye type, or vial-type.


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LEVEL RODS

Graduated rods made of wood, fiberglass, or metal.

Graduations in feet and decimals.

Self-reading rods: Can be read by the instrument operator by sighting through the

telescope and noting the apparent intersection of the cross wire on the rod. Target rods: Have a movable target that is set by the rod person at the position indicated

by signals from the level operator.

RESULT:

The Details of all levelling instruments as mentioned above has been learnt properly.


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Ex No: 7 Date:

FLY LEVELLING

AIM:

To determine the height and reduced levels in given ground surface.

INSTRUMENT REQUIRED:

Dumpy level

Leveling staff

PROCEDURE:

All temporary adjustments are done after setting the instruments at one station A. Now

one point is selected as a bench mark.

The back sight reading for benchmark with known elevation, inter sight for other points

and foresight reading were taken from the instrument station.

Then the instrument is shifted to another station B. The initial adjustments are done

before taking reading in the new station.

There may be number of change points according to topography of the ground.

This process is repeated for required number of change points.

Finally the Reduced level of each point is calculated by

Height of collimation = RL of Benchmark +Back sight reading over BM

RL of Points= inter sight or fore sight


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OBSERVATION: FLY LEVELLING

POINT BS IS FS HOC RL REMARK

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17


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CALCULATION: :(INCLUDING BOTH HOC & RISE AND FALL METHOD)

RESULT:

Leveling with a height of collimation is done.


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Ex No: 8 Date:

CHECK LEVELLINGAIM:

To check the levels in ground surface.

INSTRUMENTS REQUIRED:

Dumpy level

Levelling staff

PROCEDURE:

All temporary adjustments are done after setting the instruments at one station A. Now

one point is selected as a bench mark with known RL.

The back sight reading for benchmark with known elevation, inter sight for other points

and foresight reading were taken from the instrument station.

There may be number of change point according to the topography of ground. For checking levels leveling procedure is repeated in the reverse manner in which the

instrument stations are first selected.

Thus the leveling procedure is finally closed at the place where bench mark is selected

first.

The Reduced level of each point is calculated by

Height of collimation = RL of Benchmark +Back sight reading over BM

RL of Points=

inter sight or fore sight

Arithmetic check:

FS~BS= First RL ~ Last RL


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OBSERVATION: CHECK LEVELLING

POINT BS IS FS HOC RL REMARK

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19


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CALCULATION:( INCLUDING BOTH HOC &RISE AND FALL METHOD)

RESULT:

Levelling with a height of collimation is done.


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Ex No: 9 Date:

LONGITUDINAL SECTION AND CROSS SECTIONAIM

To plot the profile of the ground by finding the elevation of points at fixed intervals

along a fixed line.

INSTRUMENT USED

Tape

Chain

Arrows

Cross staff

Ranging rod

Dumpy level

Levelling staff

PROCEDURE:

Set the instrument at one side of the profile line and do all the temporary and permanent

adjustments.

The longitudinal profile is selected on the ground.

The cross section profiles are fixed in the longitudinal profile by fixing perpendicular.

The cross section profile is also divided into number of constant interval.

The cross sectional levels are taken on the right and left of left side of the longitudinal

profile.

The RL of various point are calculated using the HOC method.

The graph is then plotted by considering the distances in X axis and RL in Y axis


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STATIONDISTANCE

B.S. I.S. F.S. HOC RL REMARKL C R

BM

0

5

10

15

20

25


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CALCULATION:( HOC METHOD)

RESULT:

Thus the profile at ground is plotted by determining the elevation of point at fixed

interval along a fixed line.


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Ex No: 10 Date:

PLANE TABLE SURVEYINGRADIATION

AIM:

To draw the ray for the object from a single stadia point.

INSTRUMENT USED:

Plane table

Alidade

Sprit level

Plumping fork

Compass

Drawing paper

PROCEDURE:

Set the instrument at station O, Level and transfer the point on the sheet by means of

plumbing fork. This point represents the instrument station on ground.

With the help of trough compass mark the north direction on the sheet.

A pin may be kept inserted at O and the alidade may be kept touching the pin while

sighting the points.

Keep the alidade touching O and sight to A.

Draw a ray along the edge of the alidade, similarly sight different point B, C, D, and etc.

and draw the corresponding rays.

Measure the distance between the instrument station and various sighted points like OA,

OB etc.

RESULT:

The positions of the points are thus mapped by way of radiation.


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Ex No: 11 Date:

PLANE TABLE SURVEYINGINTERSECTION

AIM

To map the given section points by intersection method.

INSTRUMENT USED:

Plane table

Alidade

Sprit level

Plumping fork

Compass

Drawing sheet

PROCEDURE:

Set the table at one point (A) and level it and transfer the point on the sheet by way of

plumping fork. Clamp the table.

With the help of trough compass, mark the north direction on the right top of the sheet.

Pivoting the alidade about a, sight it to B. Measure the distance between two station (say

AB)plot it along the ray to get b. The base line ab is thus drawn.

Pivoting the alidade about first station point(a), sight the details C, D, E etc and draw

corresponding rays.

Shift the table to B and set it there. Orient the table roughly by compass and finallybisecting A.

Pivoting the alidade about b, sight the details C, D, E etc and draw the corresponding

rays along the edge of the alidade to intersect with previously drawn rays in c, d, e etc.

RESULT:

The positions of the points are thus mapped by way of intersection.


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Ex No: 12 Date:

PLANE TABLE SURVEYINGTHREE POINT PROBLEM

AIM:

Three point problem in plane table surveying.

APPARATUS:

Plane table alidade,

plumbing fork,

plumb bob,

Ranging rod,

drawing sheet.

THEORY:

It is finding the location of the station occupied by a plane table on the sheet by means

of sighting to three well-defined points of known location on the sheet. The principle of this

method lies in the fact that if the plane table is correctly oriented, the three resectors through a

,b,& c, shown in fig. meet at a point p which is the location of the plane-table station on the

sheet, provided the point A,B,C& P do not lie on the circumference of a circle. By

solving three-point problem, thus, the orientation & resection are accomplished simultaneously.

The solution of three-point problem is further illustrated graphically in fig. the stations

A, B, & C are of known position & p is of unknown position. If the angle a is observed

between PB, & PA, the position of P is indeterminate, because P can be anywhere on

the circle circumscribing the triangle PAB. Additional information is needed to make the

problem determinate. If the angle B, which is the angle subtended by AC at P, is also observed

then the solution is unique since P, A &C lie on the circle that circumscribe triangle PAC, & P is

one of the two intersection points of the circles & A is the other intersection point. This solution

becomes indeterminate of A, B, C, & P fall on the circumference of one circle.

If the two circles tend to merge into one circle, the problem will be less stable & finally

becomes indeterminate again when the two circles coincide. Points should be selected in the

field so as to avoid this situation.

There is number of solutions of three-point problem but the following

Methods applicable to the plane table discussed.

a. mechanical method ( tracing paper method )

b. graphical method

c. trial & error method ( Lehmanns method )


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Statement:

Location of the position on the plan, of the station occupied by the plane table by means of

observations to three well defined points whose positions have been previously plotted on the

plan.

PROCEDURE:-

The three point problem consists in locating on the plan the position of the

instrument station on the ground by means of observation to three well defined points whose

positions have been already plotted on the plan. Suppose A, B, &C are the three points which

have been plotted as a, b, & c on the plan & the table is set up at T from which A, B, & C are

visible. It is required to plot on the plan the position t of the instrument station T.

The problem may be solved by (1) Mechanically (2) Graphically (Bessels

method) & (3) by trial & error method

Bessels method: -

This method is simplest & most commonly used.

i. After setting & leveling the table, the alidade is placed along the line ca & the board turned

until A sighted being towards A. The table is then clamped. With the alidade centered on C,

B is sighted & a ray CB is drawn along the edge of the alidade.

ii. When the alidade placed along ac, the board is turned until the line of sight bisects c, c

being towards C & then clamped. With the alidade touching a, B is sighted & a ray aB is drawn

through a; intersecting the ray previously drawn through in the point d.

iii. With the alidade along bd, the table is turned until B is bisected & then clamped. The table is

now oriented & t must lie on db & also on Aa & Cc. with the alidade centered on a, A is

bisected & a lay is drawn through a, intersecting the ray bd in t, which represent the

instrument station T.

To check the orientation, the alidade is pivoted on c &C is bisected. The ray Cc

should now pass through t, if the work is correct.

RESULT:

The location of the instrument station on a given point is found on sheet.


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Ex No: 1 3 Date:

PLANE TABLE SURVEYINGTWO POINT PROBLEM

AIM

To locate the instrument station by two point problem.

INSTRUMENT USED:

Plane table

Alidade

Sprit level

Plumping fork

Compass

Drawing sheet

Statement:

Location of the position on the plan, of the station occupied by the plane table by

means of observations to two well defined points whose positions have been previously plotted

on the plan

PROCEDURE:

Choose an auxiliary point D near C, to assist the orientation at C. Set the table at D in

such a way that ab is approximately parallel to AB. Clamp the table.

Keep the alidade at a and sight A. Draw the resector. Similarly draw a resector from b

and B to intersect the previous one in d. The position of d is thus got, the degree of

accuracy which depends upon the approximation that has made in keeping ab parallel to

AB. Transfer the point d to ground and drive a peg.

Keep the alidade at d and sight C. Draw the ray. Mark a point C1 on the ray by estimation

to represent the distance DC.

Shift the table to C, orient it by taking back sight to D and centre it with reference to C 1.

The orientation is, thus, the sane as it was at D.

Keep the alidade pivoted at a and sight it to A. Draw the ray to intersect with the

previously drawn ray from D in c. Thus c is the point representing the station C, with

reference to the approximate orientation made atD.

Pivoting the alidade about c, sight b. Draw the ray to intersect with the ray drawn fromD

to B in b. Thus b is the approximate representation ofB with respect to the orientationmade atD.`

The angle between ab andab is the error in orientation and must be corrected for. In

order that ab and ab may be coincide keep a pole P in line with ab and at a great

distance. Keeping the alidade along ab, rotate the table till P is bisected. Clamp the table.

The table is thus correctly oriented.


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After having oriented the table as above, draw a resector from a to A and anotherb to

B, the intersection of which will give the position Coccupied by the table.

RESULT:

The resection after orientation by two point problem is done


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CE2259 - SURVEY PRACTICAL IISYLLABUS

CE2259 SURVEY PRACTICAL II L T P C 0 0 4 2

OBJECTIVE

At the end of the course the student will possess knowledge about Survey field techniques.

1. Study of theodolite

2. Measurement of horizontal angles by reiteration and repetition and vertical angles

3. Theodolite survey, traverse

4. Heights and distances - Triangulation - Single plane method.

5. Tacheometry - Tangential system - Stadia system - Subtense system.

6. Setting out works - Foundation marking - Simple curve (right/left-handed) - Transition

curve.

7. Field observation for and Calculation of azimuth

8. Field work using Total Station. TOTAL: 60 PERIODS


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CONTENT

SI.NO Date Name of the ExperimentPageNo.


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Observations

HORIZONTAL ANGLES

Face least count

Fig1:Repetition method

Instrumentstation

Sight to Vernier scale A Vernier scale B meano o

Instrument

stationSight to

Vernier scale A Vernier scale B mean

o

o

2

3

B

A


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EX NO 1 DATE:

MEASUREMENT OF HORIZONTAL ANGLEREPETITION METHOD

AIM:

To measure the horizontal angle between two objects say A and B from the selected

position of point O


Theodolite with accessories

PROCEDURE

Set up the instrument at point O and do all the temporary adjustment and level it

accurately, then bring the face of the instrument left.

Set the vernier A to zero by using upper clamp and its tangent screw then tighten the

upper clamp.

Now loosen the lower clamp, direct the telescope to the left hand object say A and bisect

A exactly using its lower clamp and its tangent screw.

Now check the vernier whether it still reads 0o

or not

Loosen the upper clamp, turn the telescope in clockwise direction and bisect the right

hand object B exactly by using upper clamp and its tangent screw.

Read both veniers A and B .to get the accurate values before proceed further.

Loosen the lower clamp and turn the telescope until the object A is sighted. Again bisect

A very accurately using lower tangential screw

Loosen the lower clamp and turn the telescope in clock wise direction and again sight

towards B. Now the vernier will read twice the value of previous angle.

Repeat this procedure at least three times.

By taking the average value we get the exact value of angle AOB

Change the face of the theodolite that is vertical circle being right to the observer and

repeat the above steps.

By taking the average value of face left and face right observations, we get the exact

value of angle AOB.

RESULT:

Horizontal angle AOB = .


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EX NO 2 DATE:

MEASUREMENT OF HORIZONTAL ANGLEREITERATION METHOD

AIM :

To measure the horizontal angles between objects sayA, B, C, D andEfrom a particular

station O



PROCEDURE

1) Set up the instrument at point O and do all the temporary adjustments and level it

accurately.

2) Set the vernier A to zero by using upper clamp and its tangent screw and then tighten the

upper clamp

3) Direct the telescope object A, bisect it accurately using the lower clamp and its tangentscrew .Now check whether it still reads 0oor not

4) Loosen the upper clamp screw, turn the telescope in clock wise direction and bisect the

right hand object B exactly by using upper clamp and its tangent screw.

5) Read both verniers A and B. The mean of the two vernier readings will give the angle

AOB

6) Similarly bisect B, C, D and E. Read both the veniers at each bisection. Find the values

of included angles.

7) Finally close the horizon by sighting towards the initial point. Now the vernier should

read 360o if not note down the closing error

RESULT:

The horizontal angles between various objects are .


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Observations

VERTICAL ANGLE

Face least count

Face least count

Fig 3: Vertical angle

Instrumentstation

Sight toVernier scale A Vernier scale B mean

o o

Instrumentstation

Sight toVernier scale A Vernier scale B mean

o o

O

Level line

B

U

I

L

D

IN

G


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EX NO: 3 DATE:

MEASUREMENT OF VERTICAL ANGLEAIM:

To find the vertical angle of an elevated object.



PROCEDURE

1) Set up the instrument at station point O and level it accurately with reference to the

altitude level.

2) Keep the altitude level parallel to any two foot screws and bring the bubble to the center.

3) Rotate the telescope through 90o

till the altitude bubble is on the third foot screw.

4) Bring the bubble to the center using third foot screw. Repeat the procedure till the bubble

is center at both the position.

5) Loose the vertical circle, clamp and rotate the telescope in vertical plane to sight the

object.

6) Read both veniers C and D of the vertical circle.

7) Now transit the telescope towards the required position of the object (ie) towards the top

of the tower and clamp the screw.

8) Read both veniers C and D of the vertical circle and the mean of these two readings gives

the actual vertical angle.

RESULT:

The vertical angle of the elevated point =


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Observations

VERTICAL ANGLE

Face least count

Fig4 :vertical angle

Instrumentstation

Sight toVernier scale C Vernier scale D mean

o

o

D

Level line

h

BMO

V


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EX NO: 4 DATE:

BASE ACCESSIBLE METHODAIM:

To find the elevation of an object, when its base is accessible.



PROCEDURE


altitude level.

2) Take a staff reading S on the bench mark with line of sight being horizontal so as to

determine the elevation of line of sight.

3) Now direct the telescope towards the object and observe the vertical angle

4) Average value of face left and face right observations will give the actual vertical angle.

Note:

Face left and face right observations should be taken to eliminate the instrumental error.

h= D tan 2

Thus height of object Q above the horizontal line of sight ie QQ is determined.

FORMULA USED:

RL of Q = RL of BM + staff reading over BM + vertical component

RESULT:

RL of point elevated object =


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EX NO: 5 DATE:

SINGLE PLANE METHODAIM:

To find the elevation of an object Q, when its base is inaccessible.



Measuring tape

Levelling staff

PROCEDURE:


altitude level.

2) Direct the telescope with face left towards the top of the object Q. Bisect accurately and

read both C and D verniers to determine the vertical angle 1.

3) Change the face to right and again measure vertical angle 1.4) Set the vertical circle verniers to read zero and altitude bubble centered, take a staff

reading S1on the staff held on BM.

5) Shift the instrument to the new position R at a distance b from O. Set up and level it

accurately.

6) Now measure the vertical angle 2 by taking both face left and face right observations.

7) Set the vertical circle verniers to read zero and altitude bubble center take a staff reading

S2 on the staff held on BM.

FORMULA USED:

RL of Q = RL of BM+ staff reading over BM. +V1

RL of Q = RL of BM+ staff reading over BM. +V2

D = S+ b tan 2/ (tan 1-tan2)

.


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Observations

VERTICAL ANGLES

Face least count

Instrumentstation

Sight toVernier scale C Vernier scale B mean

o o

Instrumentstation

Sight toVernier scale C Vernier scale D mean

o

o


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HILL

Fig5: single plane method

Calculation:

RESULT:

RL of top of hill=

Level line

1

BM

2

P1P2

b

V1 V2

S


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EX NO: 6 DATE:

TANGENTIAL METHOD OF TACHEOMETRY

(BOTH ANGLES ARE IN ELEVATION)

AIM:

To find the elevation of an object Q, when both angles are in elevation.



Leveling staff

PROCEDURE


altitude level.2) Hold the levelling staff on BM and take the staff reading on it say h

3) Again set the vertical circle to read zero and level it with reference to altitude level.

4) Hold the levelling staff over the required object Q and fix two target points A and B with

a fixed interval S (say 2.5m)

5) Now direct the telescope towards the top target A, get the axial hair ray coincide with top

target A and measure the angle 1 with face left and face right.

6) Again set the vertical circle to read zero and direct to the bottom target B with axial hair

coincides with target B, and measure the vertical angle 2 with face left and face right

observations.

FORMULA USED:

V = D tan 2

S+V = D tan 1

D = s/ (tan 1-tan2)

RL of Q = RL of BM + Height of Inst.(h)+V1

RL of Q = RL of BM + Height of Inst.(h)+V2


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Fig6: Both angles are in elevation

RESULT:

RL of top of hill=

s

A

B

P

h

D

V

2

r

Level line


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EX NO 7 DATE:

TANGENTIAL METHOD OF TACHEOMETRY(BOTH ANGLES ARE IN DEPRESSION)

AIM:

To find the elevation of an object Q, when both angles are in depression.



Levelling staff

PROCEDURE


altitude level.

2) Hold the levelling staff on BM and take the staff reading on it say h3) Again set the vertical circle to read zero and level it with reference to altitude level.

4) Hold the leveling staff over the required object Q and fix two target points A and B with

an interval s(say 2.5m)

5) Now direct the telescope towards the top target A, get the axial hair ray to coincide with

top target A and measure the angle 1 with face left and face right.

6) Again set the vertical circle to read zero and direct the bottom target B to coincide with

axial hair and measure the vertical angle 2 with face left a face right observations.

FORMULA USED:

V = D tan 2

S+V = D tan 1

D = s x tan 2/ (tan 1-tan2)

RL of Q = RL of BM1+Hight of Inst. +V1

RL of Q = RL of BM2+Hight of Inst. +V2


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Fig 7: both angles are in depression

RESULT:

RL of top of hill=

Level line

B

A

Q1

V

Q

r

s

P

1 2

D


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EX NO 8 DATE:

SUBTENSE TACHEOMETRYAIM:

To determine the horizontal distance between two stations using subtense bar.



Subtense bar

arrows

PROCEDURE

1) Set up the instrument at station point P and level it accurately with reference to the

altitude level.

2) Place the subtense bar over the station Q and fix the targets or vanes with a minimum of

3m intercept.

3) Set the vernier A of theodolite to read zero and direct the telescope to bisect the target at

one end of the subtense bar, the vernier A reading zero only.

4) Turn the telescope to bisect the target at other end of the subtense bar.

5) Thus the horizontal angle between these two targets is measured and is taken as .6) Convert these horizontal angles in terms of seconds.

7) Apply the following formula to find out the horizontal distance D.

FORMULAS USED:

D = X 206265

Where is in seconds

Fig 8: subtense tachometry

RESULT: The horizontal distance between the two stations=..m

A

B

S

D

P


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EX NO 9 DATE:

SETTING OUT OF FOUNDATION

AIM:

To set out the outline of foundation trench for the given room dimension.

INSTRUMENT REQUIRD:


Tape

Ranging rod

Arrows and thread

PROCEDURE

1) Set the instrument over the station point A and do all the temporary adjustments.

2) Set the vernier A to read zero and focus the line AC and fix the ranging rods at point Band C with the help of tape.

3) Turn the telescope to 90o anticlockwise and focus the line AF and fix the ranging rod at

F.

4) Shift the instrument to the station point B and make the vernier A to read zero by

focusing the line BC and turn the telescope 90o anti clock wise and fix the point E.

5) Shift the instrument to the station point C and make the vernier A to read zero by

focusing the line CA and turn the telescope 90o anti clockwise and fix the point D.

6) Shift the instrument to the station point D and make the vernier A to read zero by

focusing the line DC and turn the telescope 90o anticlockwise and check whether the

point E and F are in same line.7) Remove the ranging rods and fix the arrows by stretching a line at a distance for half the

width of the foundation.

8) Then with the help of tape, mark the foundation offset side by side of the center line.

9) Repeat the offset marking for all the center lines.


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A B C

6m x 4 m 8m x 4 m

F E D

Fig 9:setting out of foundation

Check:

Calculation Check for diagonal length:

Using the relation AE2=AF2+FE2

RESULT:

Thus the outline of the foundation trench has been set up for the room of given size.


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L

R R

Fig 10: setting out of simple circular curve linear method (model figure)

RESULT:

Simple circular curve for radius 100m and length of long chord 80m by offset from long

chord method is done.

T1 T2

O


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EX NO :11 DATE:

SETTING OUT OF A TRANSITION CURVE

AIM :

To set a transition curve (cubic spiral) from the following data by the method of deflectionangles.

INSTRUMENT REQUIRD:


Tape

Ranging rod

Arrows and thread

PROBLEM:

Length of the transition curve L=20m

Radius of circular curve R=50m

Peg interval l=2.5m

PROCEDURE:

Set the instrument over the station point A and do all the temporary adjustments.

Set the vernier A to read zero, bisect the ranging rod and fix the point B. This point is a

reference point for a straight arc.

By loosening the upper screw rotate the telescope clockwise and set deflection angle1and clamp both the screws.

From A take the first chord length in the tape and bisect the line of collimation using a

ranging rod and fix the point P1, on the ground.

Take the second deflection angle 2, from the point A take the second chord length in

the tape, and use the ranging rod to fix the point P2 on the ground.

Similarly repeat the whole steps to get the points like P3, P4 etc.

Join all the points to get the required curve.

As a check, calculate the spiral angle --, this should be three times the least deflection

angle.

Check

Delta s = 1719 L/R


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Fig 11: setting out of transition curve(model figure)

RESULT:

Thus setting out of transition curve is done in the field by using the given data.

3

1,

A

BTransition curve

2

3

1,

Tangent line


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EX NO: 12 DATE:

SETTING OUT OF A SIMPLE CURVEUSING RANKINES METHOD

Aim :

To range the curve at the field using theodolite from the following datas using Rankines

method.

INSTRUMENT REQUIRD:


Tape

Ranging rod

Arrows and thread

PROBLEM:

Radius of curve = 15m

Intersection angle = 100o

Peg interval = 2m

Chainage at intersection point =200m

PROCEDURE:

Set the theodolite at the point of curve (T1). With both plates clamped to zero, direct the

theodolite to bisect the point of intersection (V). The line of sight is thus in the direction

of the rear tangent.

Release the vernier plate and set angle /\ 1on the vernier. The line of sight is thus directed

along chord T1 A.

With the zero end of the tape pointed at T1and arrow held at a distance T1A= c along

chord T1A = c along it, swing the tape around T1 till the arrow is bisected by the cross

hairs. Thus, the first point A is fixed.

Set the second deflection angle /\ 2 on the vernier so that the line of sight is directed

along T1 B .

With the zero end of the tape pinned at A, and an arrow held at distance AB = C along it,

swing the tape around A till the arrow is bisected by the cross-hairs thus fixing the point

B.

Repeat the steps (4) and (5) till the last point T2 is reached.


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Surveying Observation, surveying, observation

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