ce6413 survey practical ii lab manual

7/26/2019 CE6413 Survey Practical II Lab Manual

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PAAVAI ENGINEERING COLLEGE, NAMAKKAL

CE6413

SURVEY PRACTICAL - II

LAB MANUAL

ANNA UNIVERSITY:: CHENNAI 600 025

PAAVAI ENGINEERING COLLEGE, NAMAKKAL


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CE6413Survey Practical II - Lab Manual

2

CE6413- SURVEY PRACTICAL II SPLITUP DETAILS

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

LIST OF EXPERIMENTS

Ex.

No.

Experiment Name Hours Remarks

1 Study of theodolite. 3Study the different components

of Theodolite.

2Measurement of horizontal angles byrepetition Method.

3Measure the Horizontal anglebetween two points by methodof Repetition.

3Measurement of horizontal angles byreiteration method.

3Measure the Horizontal anglebetween two points by methodof Reiteration.

4 Measurement of height of a building byusing vertical angles

3 Measure the height of thebuilding using vertical angles.

5 Theodolite survey traverse 3Obtaining the included anglesbetween objects.

6 Constant of a Tacheometer 3Finding the Tacheometerconstants.

7Determination of distance and elevation ofan object by Stadia system.

3Determining the distancebetween two points and Heightof an object.

8 Single plane method. 3Finding the elevation of theobject by using same line offocus.

9Determination of distance and elevation ofan object by Tangential method.

3Determine the distance andelevation of an object byTangential method.

10 Double Plane method. 3Finding the elevation of theobject by using different line offocus.

11 Setting out works - Foundation marking. 3 To setting out the practical

application like, foundation andcurves.12 Setting out works - Simple curve. 3

13 Setting out works -Transition curve. 3

14 Field observation and Calculation of azimuth 3

To find the True meridian of a

survey line, determination of the

azimuth of the line is necessary.

15 Field work using Total Station. 3Getting to know about theelectronic total station and itsapplication.


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SURVEY PRACTICAL- II LABORATORY

GENERAL INSTRUCTIONS

1. All students are instructed to wear protective uniform, shoes and cap during labsessions.

2. Before doing any exercise, students should have a clear idea about the

principles of that exercise. They should come with observation note with unfilled

tabular column. Viva questions will be asked by the Staff regarding the

particular experiment.

3. All students are advised to come with completed record and corrected field

book of previous experiments; defaulters will not be allowed to do theirexperiment.

4. Students shall not use any instrument without getting concerned staff members'

prior permission.

5. Utmost care must be taken to avert any possible injury while on laboratory work.

In case, anything occurs immediately report it to the staff members.

6. One student representing each batch should receive the instrument on behalf of

his their batch.

7. All instruments and accessories should be handed over to the technicians of the

lab as soon as the exercises are over and before leaving the laboratory.

8. All instruments are costly. So the permanent adjustment screws of theodolites,

levelling and other instruments shall not be tampered. They must be handled

carefully, to avoid fine for any breakage.

Staff In-charge HOD / Civil Engg.


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ANNA UNIVERSITY CHENNAI(REGULATIONS 2008)

CE6413 - SURVEY PRACTICAL II

SYLLABUS

OBJECTIVE

At the end of the course the student will posses knowledge about Survey fieldtechniques.

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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CE6413 - SURVEY PRACTICAL IITEACHING SCHEDULE

Sl. No. I CYCLENumber

ofPeriods

1Study Of Theodolite, Measurement OfHorizontal AngleRepetition Method

3

2Measurement Of The Horizontal Angle -Reiteration Method

3

3 Measurement Of Vertical Angles 3

4 Theodolite Traversing 3

5 Trigonometry - Single Plane Method 3

6 Tangential Tacheometry 3

7 Model Test 1 4

II CYCLE

8Stadia Tacheometry - Determination OfTacheometric Constants

3

9Stadia Tacheometry - Determination Of

The Gradient Of The Line

3

10Subtense Bar - Gradient Joining InstrumentStation And Target Of Subtense Bar

3

11Subtense Bar - Gradient Joining Staff StationAnd Target Of Subtense Bar

3

12 Setting Out Of Foundation 3

13Setting Out Simple Circular Curve - Rankine'sMethod

3

III CYCLE

14Setting Out Simple Circular Curve-Two Theodolite Method

3

15 Setting Out Of Transition Curve 3

16 Field Observation And Calculation Of Azimuth 3

17 Study Of Electronic Total Station 3

Revision / Repetition Class 4

Model Test 2 4

Total Number of Periods required 60


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CONTENTS

Sl.

No.Name of the experiment

PageNo.

1 Study Of Theodolite 7

2Measurement Of Horizontal AngleRepetitionMethod

10

3Measurement Of The Horizontal Angle -Reiteration Method

12

4 Measurement Of Vertical Angles 13

5 Theodolite Traversing 14

6 Trigonometry - Single Plane Method 16

7 Tangential Tacheometry 18

8Stadia Tacheometry - Determination OfTacheometric Constants

20

9Stadia Tacheometry - Determination OfThe Gradient Of The Line

22

10Subtense Bar - Gradient Joining InstrumentStation And Target Of Subtense Bar

24

11Subtense Bar - Gradient Joining Staff StationAnd Target Of Subtense Bar

26

12 Setting Out Of Foundation 28

13Setting Out Simple Circular Curve - Rankine'sMethod

30

14Setting Out Simple Circular Curve-Two Theodolite Method

31

15 Setting Out Of Transition Curve 33

16 Field Observation And Calculation Of Azimuth 37

17 Study Of Electronic Total Station 40


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Ex.No: 1

Date: STUDY OF THEODOLITE

DESCRIPTION OF THE INSTRUMENT: TRANSIT THEODOLITE

The telescope can be revolved through a complete revolution about its horizontal axis in avertical plane.

PARTS:

A) Levelling Head:

1. A levelling head consists of two parallel triangular plates known as tribrach plates.

2. The upper tribrach has three arms each carrying a levelling screw.

3. The main functions of the levelling head is

(i) to support the main part of the instrument

(ii) to attach the theodolite to the tripod

(iii) to provide a mean for levelling the theodolite

B) Telescope:It is mounted on a spindle known as horizontal axis or trunnion axis.

C)Vertical Circle:

1) It is a circular arc attached to the trunnion axis.

2) By means of vertical clamp screw and tangent screw the telescope can be accurately set

at any desired position in vertical plane.

3) The graduation in each quadrant are numbered from 0 to 90 in opposite directions.

D)Index Frame:

1) At the two extremities, two verniers are fitted to read the vertical axis.

2) When the telescope is moved in a vertical plane, the vertical circle moves relative to the

verniers with the help of which reading can be taken.

3) A long sensitive bubble tube is placed on the top of the index frame.

E)Standards (or) A - Frame:

This stands upon the vernier plate to support the horizontal axis.

F)Two Spindles:

The two axes have a common axis which forms the vertical axis of the instrument.

G)Lower Plate:

1. It carries a horizontal circle graduated from 0 to 360 in a clockwise direction as a

silvered, bevelled edge.

2. By means of clamp screw and tangent screw this can be fixed at any desired position.H)Upper Plate:

1. It also carries clamp and tangent screw to accurately with the lower plate.

2. On clamping the upper clamp and unclamping the lower clamp, the instrument can

rotates on its outer axis without any relative motion between the two plates.

3. If the lower clamp is clamped and upper clamp unclamped, the upper plate and the

instrument can rotate on the inner axis with a relative motion between the vernier and the

scale.

4. For using any tangent screw, its corresponding clamp screw must be tightened. H)

Level Tubes:

1. The upper plate carries two level tubes placed at right angles to each other inwhich one is kept parallel to the trunnion axis.


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2. These can be centered with the help of foot screws.

I) Plumb Bob:

This is suspended from the hook fitted to the bottom of the inner axis to centre the

instrument exactly over the station mark.

TEMPORARY ADJUSTMENTS:

1)Setting Over The Station:

1. Centre the instrument over the station mark by a plumb bob.

2. Level approximately with the help of tripod leg.

2)Levelling Up:

Do this by using three foot screws similar to that of levelling instrument.

3)Elimination of Parallax:

1. By focusing the eye-piece for distinct vision of the cross-hairs.2. By focusing the objective to bring the image of the object in the plane of cross hairs.

IMPORTANT TERMS:

Vertical Axis:

The axis about which the theodolite may be rotated in a horizontal plane.

Horizontal Axis:

The axis about which the telescope along with the vertical circle of a theodolite may be

rotated in a vertical plane.

Axis of telescope:

The axis about which the telescope may be rotated is called axis of telescope.

Axis of the level tube:

The straight line which is tangential to longitudinal curve of the level at its centre is called

axis of the level tube.

Centering:

The process of setting up theodolite exactly over the ground work station is known as

centering.

Transiting:

The process of turning the telescope in vertical plane through 180 about its horizontal axisis known as transiting.

Swing:

A continuous motion of the telescope about the vertical axis in horizontal plane is called

swing. The swing may be either in face left or right.

Face left Observation:

The observations of angles when the vertical circle is on the left side of telescope.

Face right observation:

The observation of angles when the vertical circle is on the right of telescope.

Changing the face:

The operation of changing the face of telescope from right to left and vice-versa.

A Set of observations


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A set of horizontal observations of any angle consists of two horizontal measures one on the

left face and other on the right face.

Telescope Normal:

A telescope is said to be normal when its vertical circles is to its left and bubble of the

telescope is up.

Telescope inverted:

A telescope is said to be inverted or reversed when its vertical circle is to its right and the

bubble of the telescope is down.


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Ex.No: 2

Date:

MEASUREMENT OF HORIZONTAL ANGLE REPETITION METHOD

Aim:

To determine the included angle between two object stations P and Q by using repetitionmethod.

Instruments required:Theodolite, Tripod

Procedure:

1. Set the instrument at "S" approximately at the middle of the given objects to avoid too

obtuse and too acute angles.

2. Do all initial adjustments with face left.

3. Rotate the upper plate clockwise or anticlockwise so that the zero mark of the A vernier

scale coincides with the zero mark of the main scale. Similarly Vernier B will read 180o.

Now tight the upper clamp.

4. Loosen the lower clamp screw and direct the telescope towards the object P. See

whether the vernier readings reads 0oand 180

ostill.

5. Tighten the lower clamp and loosen the upper clamp, and bisect point Q accurately by

lower tangent screw.

6. Note the readings of verniers A and B to get the horizontal

angle of PSQ.

7. Loosen the lower clamp screw. Turn the upper plate clockwise

to sight "P" again and bisect accurately by lower tangent

screw.

8. Repeat steps 5 to 8, until the angle is repeated to the

required number of repetitions. (Usually 3)

9. Change the face to right, and set the Vernier A to 180oto eliminate graduation error in

horizontal circle and note the readings similarly as above.

Practical Applications:

1. Repetition method is used during triangulation and in theodolite traversing.

2. Small horizontal angles have to be measured accurately.


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Result:Average Horizontal angle PSQ =

In

stat

Sightto

Face : Left Swing : Right Face : Right Swing: Right Average

Horizontal

Angle

2

)2()1( A B Mean

NoofRep

HorizontalAngle

(1)

A B Mean

NoofRep

HorizontalAngle

(2)

' " ' " ' " ' " ' " ' " ' " ' " ' "

S P 1 1

Q 2 2

Q 3 3

Average Average


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Ex.No. 3

Date:

MEASUREMENT OF THE HORIZONTAL ANGLE

BY USING REITERATION METHOD

Aim :To determine the included angle between the given stations by reiteration method

Instruments required :

Theodolite with stand, Ranging rods, Tape, Plumb Bob

F

Procedure :

1. Set the instrument over "S" which should be at the centre of the arrangement of the givenobjects.

2. Do all the initial adjustments and keep the vertical circle to right.3. With face left, set vernier A to 0 and bisect the ground point 'A' and turn the telescope to

object B by loosening the upper clamp.4. In the same way bisect the other objects in clockwise direction and note down the

readings.5. Do the same procedure with the face right.


1. This method is suitable when several angles are to be measured from a samestation.

2. Several angles can be measured successfully and finally the horizon can be closed.

Instat

Sightto

Face : Left Swing : Right Face :Right Swing : Left

A B MeanIncludedAngle

A B MeanIncludedAngle

AverageIncludedAngle

' " ' " ' " ' " ' " ' " ' " ' " ' "

S A

B

C

D

E

F

A

Result :

1) ASB 2) BSC 3) CSD 4) DSE 5) ESF 6) FSA

A

B C

D

E

S


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Ex.No: 4Date:

MEASUREMENT OF VERTICAL ANGLESAim :To determine the vertical angles of the given objects.

Instruments required : Theodolite with tripod, Plumb BobProcedure :1. Set up the instrument at any convenient place to cover all the given points.2. Level the instrument with reference to the altitude bubble by using foot screws as in the

case of horizontal bubble levelling.3. Set the zero of the vernier Cexactly in coincidence with the zero of the vertical scale.4. Loosen the vertical plane until the focused object is bisected. Use tangent screw for

accurate bisection.5. Read both the verniers C and D of vertical circle.6. Denote the elevation angle with +ve sign and depression angle withve sign..7. Similarly bisect all other objects and find out the readings accurately.8. Change the face and follow the steps 4 to 6 above.

DETERMINATION

OF VERTICAL ANGLE


1. Vertical angle determination is used to find the height of towers, church piers, tallbuildings etc.

2. It is used to determine whether the line of sight is above or below the horizontalplane.

Inst at Sight to

Face : Left Face : Right

C D MeanVerticalAngle

C D MeanVerticalAngle

AverageVerticalAngle

A ' " ' " ' " ' " ' " ' " ' " ' " ' "

Result:

1) Vertical Angle of the given object 1 =2) Vertical Angle of the given object 2 =


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Ex.No: 5

Date: THEODOLITE SURVEY TRAVERSE

Aim:

To run survey lines between various field objects by traversing and to find the area between givenstations.

Instruments required:Theodolite, Ranging rods, Tape

Procedure:

1. Set up the North direction by using Surveyors compass at A.

2. Set up a theodolite with face left at station A. Centre it over the ground station mark

and level it accurately with leveling screws.

3. Sight the telescope towards station B, by making the horizontal vernier A to read

zero.4. Turn the telescope clockwise and sight F. Read both the verniers A and B, which will

give the BAF .5. Repeat the procedure with face right. Find the mean included angle.

6. Shift the theodolite to the next traverse station (B) and repeat the steps 1 to 5 at

every traverse station in the same sequential order, for measuring the included

angles at B, C, D, E, and F.

7. Plot the traverse to suitable scale in a graph sheet or A3 size sheet.

Fig. Theodolite Traversing (Schematic diagram)


1. Closed traverse is suitable for locating the boundaries of lakes, woods etc.

2. It is also used for the survey of large areas.

3. Open traverse is used for surveying a long narrow strip of land as required for a road or acanal or the coastal line.

E


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Inst

at.Sight to

Face : Left Swing Right Face : Right Swing : RightAverage

horizontal

angle

Side

and

length

BearingA B Mean Horizontal

angle

A B Mean Horizontal

angle

' " ' " ' " ' " ' " ' " ' " ' " ' "

AF 0 0 0 0 0 0 0 0 180 0 0 0 0 180 0 0

B

BA 0 0 0 0 0 0 0 0 180 0 0 0 0 180 0 0

C

CB 0 0 0 0 0 0 0 0 180 0 0 0 0 180 0 0

D

D

C 0 0 0 0 0 0 0 0 180 0 0 0 0 180 0 0

E

E D 0 0 0 0 0 0 0 0 180 0 0 0 0 180 0 0

F

F E 0 0 0 0 0 0 0 0 180 0 0 0 0 180 0 0

A

Result :

The traverse done in the field, bearing between the lines are found and the traverse is plotted and the area is found.


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CE6413- Survey Practical II - Lab Manual

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Ex.No: 6Date: TRIGONOMETRY - SINGLE PLANE METHOD

Aim:

To determine the elevation of an inaccessible object (Tower)

Instruments required: Theodolite, Levelling Staff, Ranging rod, Tape

Procedure:

1. Set up the theodolite at P, level it carefully and observe the angle of elevation 1.

2. Set the vertical vernier to zero, and note the central hair reading on a staff heldvertically on a B.M. Let it be S1.

3. Transit the telescope, so that the line of sight is reversed.

4. Mark a point R in the line of sight at a convenient distance d . Measure itaccurately.

5. Shift the theodolite to the point R, centre it and level it. Observe the angle ofelevation 2.

6. Set the vernier C to zero and take again a B.M. reading (central hair) as S2.

Instrument axis at P is higher th an R: (S1> S2)

h1= D tan 1

h2 = (d + D ) tan 2

S = Average of S2Average of S1

h1h2= S

D =21

2

tantan

Stand

R.L. of tip of the tower Q = R.L. of B.M. + S1+ h1


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Ex.No: 7Date: TANGENTIAL TACHEOMETRY

Aim:

To determine the gradient of the line joining the given staff stations A and B and to find theRL of station B.

Instruments Required: Theodolite, Tape, Peg, Target Levelling staff

Procedure:

1. Set up the instrument approximately between the given objects and do the initialadjustments.

2. Direct the telescope towards the staff at A and note the central hair reading ho.Find the vertical angles by bisecting the staff at two points in the target levelingstaff. The vertical angles may be both at elevation or both at depression or oneelevation and one depression.

3. Now turn the horizontal plate clock-wise and sight towards B. Note the horizontal

angle .

4. Take the vertical angles at B and find the target distance S.

Take

RL of BM at A = 100.000mS = __________m (Target distance)

1& 2= Vertical angle to upper and lower targets respectively.h1= Height of lower target above foot of ranging rodh0 = Height of instrument above datum line

V = Level difference between A and B = D tan 2R.L of H.I = R.L. of B.M. + h0R.L. of B = R.L. of H.I + V- h1


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Let X = Horizontal distance between A and BThen, from the above figure,

X2= D1

2+ D2

22D1D2cos

where D1=21

1

tantan

Sand D2=

21

2

tantan

S, = horizontal angle bet A and B

Gradient between A and B =X

V


1. This method is adopted in obstacles such as steep & broken ground, deep ravines, stretchesof water or swamp and so on, which makes chaining difficult or impossible.

2. This method is adopted when the theodolite is not provided with a stadia diaphragm.3. This method is also used when the staff is too far from the instrument and it is difficult to read

the staff.

TANGENTIAL TACHEOMETRY TABULAR COLUMN

Staff reading (central hair) at A = ho=__________________ m

Face : Left Swing : Left

Inst atSight

toPosition of vane

Vertical angle Horizontal angle

C D Mean A B Mean

' " ' " ' " ' " ' " ' "

P A Top vane0 0 0 0 0 0 0 0

Bottom vane

B Top vane

Bottom vane

Face : Right Swing : Right

P A Top vane0 0 0 0 0 0 0 0

Bottom vane

B Top vane

Bottom vane

Result :

1) The horizontal distance between A and B ( X ) =

2) The horizontal angle between A and B ( ) =

3) The RL of B =4) The gradient of the line joining A and B =


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Ex.No: 8Date:

STADIA TACHEOMETRY - DETERMINATION OF TACHEOMETRIC CONSTANTS

Aim:

To determine the Tacheometric constants.

Instruments required:

Tacheometer with stand, Levelling Staff, Ranging rods, tape

General:

An ordinary transit theodolite fitted with stadia hair is known as Tacheometer. This method

completely eliminated the use of tape or chain and is very rapid and convenient.

Procedure:

1. Set up the instrument at A.

2. Measure a line AB, 30 metres long on a fairly level ground and fix arrows at 10mintervals.

3. Note down the stadia hair readings (top, middle, bottom), by placing the staffover the arrow stations (PQR)

4. Keep the vertical circle to read zero during observations.

5. Calculate the other staff intercepts in the same manner.

Calculation:

Stadia intercept: S = Difference of top and bottom hair readingsLet S1, is the staff intercept corresponding to distance D1 and S2corresponding to D2. By

using tachometric equation.

D =i

fS + (f+d), since vertical angle is zero.

wherei

f= Multiplying constant denoted by k.

and (f+d) = Additive constant denoted by C.

Then D = kS + C

Now we have,

D1= CS1+ k

D2= CS2+ k

Solving the above two equations to get the values for C and k.

Similarly find out the values for C and k by other set of readings.

The average values of the C and k, will be the Tacheometric Constants.


1. Usually the constants C and k are supplied by the manufacturer of the instrument. But in order

to check the correctness of the values supplied by the manufacturer or to detect any change in

the values of the constants, they are to be determined very often in the field.


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TACHEOMETRIC CONSTANTS

Inst. at Staffstation Horizontaldistance Stadia hair readings StadiainterceptTop Middle Bottom

A P 10m

Q 10m

R 10m

Result:

Tacheometric additive constant C =

Tacheometric Multiplying Constant k =

10 20 30


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Ex.No: 9Date:

STADIA TACHEOMETRY - DETERMINATION OFTHE GRADIENT OF THE LINE

Aim:To determine the gradient of the line joining two staff stations ( P and Q).

Instruments Required:

Tacheometer, Levelling Staff.

Given: R.L. of Bench Mark = 100.000

Procedure:

1. Set up the instrument approximately between the given objects and do the initialadjustments.

2. Take horizontal angles, vertical angles, stadia readings in both the faces andswings.

Calculation:

Case: I- When the observed vertical angle is at an angle of elevation

V= the vertical distance from the instrument axis to the point C.

h = Axial hair reading; h = H.I of instrument axis

V = D tan

D = kS coscos2 C where k is the multiplication and C is the additive constant.

R.L. of Q = R.L. of H.I. + V - h

Where,

R.L. of H.I. = Elevation of B.M + Back sight (h)


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Case II- When the observed vertical angle is at an angle of depression.

R.L. of Q = R.L. of H.I. - V h

Case: III - When the observed vertical angle is zero.

R.L. of Q = R.L. of H.I. - h

D2= D12+ D2

22D1D2cos


1. This method is suitable for preparing contour maps, location surveys of roads, railways,

irrigation canals, reservoir projects and topographic surveys, where degree of accuracyneeded is not more.2. Though it is not a accurate method, it is quick and rapid method hence economical.

DETERMINATION OF THE GRADIENT OF THE LINE


Inst atSight

to

Stadia hairreading

Vertical angle Horizontal angle

C D Mean A B Mean

Top Mid Bot ' " ' " ' " ' " ' " ' "

O P

QFace : Right Swing : Right

O P

Q

Result:

The gradient of the line joining A and B =


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Ex.No: 10Date:

SUBTENSE BAR - GRADIENT JOINING INSTRUMENT STATION ANDTARGET OF SUBTENSE BAR

Aim:

To determine the gradient of the line joining the instrument station and left target of a

subtense bar.


Subtense bar, theodolite, arrow, pegs, levelling staff and tape.

Given:R.L. of B.M. = 100.000m

Procedure:

1. Set up the theodolite on the line which is fixed by viewing through sight vane ofalidade of the subtense bar.

2. Sight apex of the left target of the subtense bar and note down the vertical angleby keeping the horizontal angle as zero.

3. Sight the apex of the other target and note down vertical and horizontal angles.

4. Note down the B.M. reading

5. Measure the height of the instrument with the help of a tape.

Calculation:

L = Left target of subtense bar

R = Right target of subtense bar

O = Instrument (Theodolite) station

= Horizontal angle subtended by two targets

S = B.M. reading axial bar reading

Distance between instrument station and subtense bar (D) is given by

D = S cot /2

ho= height of target with reference to H.I.

H = D tan where = Vertical angle

R.L. of Left target L = R.L. of B.M. + ho+ H

R.L. of the instrument station = R.L. of the H.I. - Instrument height

Vo= R.L. of left target - R.L. of Instrument station

Gradient =D

V0


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GRADIENT BETWEEN INSTRUMENT STATION AND

LEFT TARGET OF A SUBTENSE BAR

Instat

Sightto

Horizontal angle Vertical angle BM

readin

gA B Mean C D Mean

' " ' " ' " ' " ' " ' "

OLeft

target

Righttarget

ORighttarget

Lefttarget

L R

1

2

+100.000 m

D


1. Subtense bar is used for the measurements of comparatively short lines in a traverse.2. It is used for measuring horizontal distances, in the areas where direct chaining becomes

difficult due to undulations or other obstructions and where accuracy required is not muchhigh.

Result:

The gradient of the line joining the instrument station and left target =

ho

Vo

H


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Ex.No: 11Date:

SUBTENSE BAR - GRADIENT JOINING STAFF STATION ANDTARGET OF SUBTENSE BAR

Aim:

To determine the gradient of the line joining the staff station and left target of subtense bar.


Theodolite, staff, arrow and subtense bar

Given:

R.L. of the B.M = 100.000 m

Procedure:

1. Set up the instrument over the line which is fixed by viewing through the sightvane of the alidade of the subtense bar.

2. Note down the hair readings at staff station at BM by setting the vertical angleand horizontal angle to zero.

3. Sight the apex of the left target of the subtense bar and note down the horizontal

angle between the staff and left target.(1

). Also note the vertical angle (1

)

4. Sight the other target and note down the vertical and horizontal angles ( 2 ) and

(2

)

SB = 2m

h Vo

S

h1

P S+100.000

D D1

1 2


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Calculation: SB = 2m

D = kS + C (Assume k = 100 and C = 0)

S is the staff intercept.

From triangle L1SR1, P

1

2 2

2 D

SBsin

D1 2

From triangle PL1S, D 1

PL1 = 11122 2 cosSLSPSLSP

V = SL1tan S

R.L. of left target = R.L. of BM +h1+ h

Gradient of L1 PL1=1

1

PLbetweendistanceHorizontal

PofR.L.LofR.L.

=1

PL

Vo

GRADIENT BETWEEN STAFF STATION AND LEFT TARGET OF A SUBTENSE BAR

Face : Left Swing : Right

Inst atSight

to

Horizontal angle Vertical angle BMreadin

gA B Mean C D Mean

' " ' " ' " ' " ' " ' "

S Staff(P)

Lefttarget

Righttarget

Face : Right Swing : Left

SStaff(P)

Left

target

Righttarget

Result:

Gradient of line joining left target of subtense bar and foot of the levelling staff (P) =


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Ex.No: 12

Date: SETTING OUT OF FOUNDATION

Aim:

To mark the centre line of foundation for the given building drawing.

General Introduction:

The process of marking on the site the intended lines of the foundation of a building is called

Setting out. This operation implies the transfer of the details of foundation from the

drawings to the actual size for forming the foundations.

Tools / Materials Required:

1. Theodolite

2. Tripod

3. A measuring tape

4. A masons square5. A roll of string

6. Steel / wooden pegs

7. A little quantity of lime powder

Procedure:

1. Study the given plan of the building and note down the internal dimension

between walls and width of foundation. Then prepare a centre line sketch of the

building.

2. Remove any vegetation in the construction site. Set-out a straight line slightly

greater than the length of the front wall of the room. This line will be the centre

line of the front wall.3. Now mark the two ends A and B of the centre line of the front wall using

theodolite. Then drive two pegs a little away from the ends marked and tie the

string accurately.

4. At the two end points A and B set-out perpendicular strings using theodolite and

stretch them. Mark the end points C and D for the side walls at the given distance

from B and A respectively.

5. Drive two pegs a little away from the point C and D and tie the string correctly,

repeat the process for the other side (rear) wall and cross wall, if any.

6. Measure the four sides of the rectangle and check its accuracy as per the centre

line sketch. Also check the diagonals.7. Then erect the centre line pillars (reference stakes)1 meter beyond the

foundation trench (usually 200mm square) and the top surface level with the

plinth level. The permanent mark made on the centre line pillars is used for

reference. (see figure)

8. Mark on the ground the width of the foundation of the walls, choosing half the

width of foundation on either side of the centre line. Apply lime powder to indicate

the outline of the foundation trench.


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Setting out of a foundation


1. Setting out of foundation marks is a must before starting any civil engineering projects.

2. On completion of the estimates from the approved plan, excavation for the foundations is

required to be made on the ground. To minimize the cost of digging foundation trenches, it is

very necessary to define the outlines of excavation stakes accurately.

Inference:

The marking of the centre line and foundation trench line were done for the given plan.


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30

Ex.No: 13Date:

SETTING OUT SIMPLE CIRCULAR CURVE - RANKINE'S METHOD

Aim:

To set out the simple curve by single theodolite method.


Theodolite, Ranging rods, chain, arrows and pegs

Principle:

Deflect ion angle:

The angle between the back tangent and the chord joining the point of commencement of

the curve and the other point on the curve

Procedure:

1. Prepare a table of deflection angles for the first subchord, normal chord and lastsubchord.

2. Set up a theodolite over T1. Direct the telescope to bisect the point ofintersection(B), with both plates clamped to zero.

3. Release the vernier plate and set angle 1 on the vernier using

4. Point the zero end of the tape at T1and an arrow held at a distance C1along itand swing the tape around T1 till the arrow is bisected by the cross hairs to fixpoint A.

5. Set the deflection angle .

where, 2= 1718.9 x C2/R min., so the line of sight is along T1B

6. With zero end of the tape pinned at A and an arrow held at distance AB = C2along it and swing the tape around A till the arrow is bisected by the cross hairsthus fixing the point B.

7. Repeat steps 5 and 6 till the last point T2is reached.

Check:

The last point so located must coincide

with the point of tangency (T2) fixed

independently by measurements from the

point of intersection.


1. This method gives accurate setting out

and is generally used for setting out

important highway & railway curves.

2. Both tape & theodolite are used for

making linear & angular

measurements.

Result:

The given simple curve is thus set out.


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Ex.No: 14Date:

SETTING OUT SIMPLE CIRCULAR CURVE- TWO THEODOLITE METHODAim:

To set out the simple curve by two theodolite method.

Instruments Required:

Two Theodolites and Ranging rods.

Principle: The angle between the target and the chord is equal to the angle which that

chord subtends in opposite segment.

Given: Chainage of the curve, angle of intersection and Radius of curve (R).

Procedure:

1. Prepare a table of deflection angle for the first sub chord, Normal chord and lastsub chord .

2. Set up one theodolite over T1and another over T2.

3. Direct the instrument at T1 to the ranging rod at the point of intersection B andbisect it.

4. Direct the instrument at T2to the first target point T1and bisect it.

5. Set the verniers of both the theodolites to read zero.

6. Set the first deflection angle (1) on both theodolites so that the telescopes are inthe direction of T1D and T2D respectively.

7. Move the ranging rod until it is bisected by the cross hairs of both the theodolitesto locate the point D on the curve .

8. Set the second value of deflection angle ( ) on both the theodolites and repeatthe step 7 above to get the location of E.

9. Continue the process for obtaining the locations of other points in a similarmanner.


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Calculation:

Given:

Chainage at B, R,

BT1 = BT

2 = R tan /2

T1T2 = 2R sin /2

Length of curve T1T2 = R180

Chainage at T1 = Chainage at BT1B

Chainage at T2 = Chainage at T1+ T1T2

Divide the length of the curve into normal Chords(30m) and subchord (C1,C2)

Deflect ion angles:

First subchord = 1718.9

Normal chord = 1718.9Last subchord = 1718.9


1. Since each point is fixed independently of the others, this method is done in the field, when

more accuracy is required.

2. An error is setting out one point is not carried right through the curve as in the rankines

method.

Result:

The given simple curve is thus set out.


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Ex.No: 15

Date:

SETTING OUT OF TRANSITION CURVE

Aim:To set out a transition curve.


Theodoloite, Ranging rods, Arrows.

General:

A transition or earment curve is a curve of varying radius introduced between a straight and

a circular curve or between two branches of a compound curve or reverse curve.

Characteristics of a transition curve:

In the figure,

Tv = Original target

Bv = the shift tangent parallel to the original tangent

S = BA = shift of the circular curve

L = length of the transition curve

D = end of the transition curve and beginning of the circular curve

DD1= tangent to both the transition and the circular curve at D.DB = extended portion of the circular curve (or the redundant circular curve).

Y = D2D =offset of the junction point D.

X = TD2 = the coordinate of the junction point D

R = radius of the circular curve

s= the spiral angle

OB = perpendicular to the shift tangent B

A = point of intersection of the perpendicular OB with the original tangent

DE = line perpendicular to OA

Since the tangent DD1 makes an angle swith the original tangent, BOD = sNow, BD = Rs

= RL / 2R since s = L/2R

= L/2

When CD is very nearly equal to BD, CD = L/2

Hence the shift AB bisects the transition curve at C.

Again

S = BA

=FAEB

= Y(OB-OE)


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= YR(1-coss)

= Y2R sin2s/2

= Y2R s2/4

where sis small.

But EA = DD2Y =R6L

PL6L

23

R24

LS

R8

L

R6

L

R2

L

4

R2

R6

LS

R2

L

2

22

22

s


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Procedure:

1. Calculate the spiral angle s by the equation s = L/2R radians2. Calculate the shift S of the circular cure by the relation S = L

2/ 24R

3. Calculate the total length of the tangent depending whether it is a spiral or cubic

parabola.

For the true spiral, the total tangent length = (R + S) tan

R5

S1

2

L

2

For the cubic spiral, the total tangent length = (R + S) tan

R5

S1

2

L

2

For the cubic parabola, the total tangent length

= (R + S) tan 2

L

2tanSR

R5

S12

4. Calculate the length of the circular curve.

5. From the chainage of PI, subtract the length of the tangent to get the chainage of the

point T.

6. To the chainage of T1add the length of the transition curve to get the chainage of the

junction point (D) of the transition curve with the circular curve.

7. Determine the chainage of the other junction point (D) of the circular arc with the

transition curve by adding the length of the curve to the chainage of D.

8. Determine the chainage of the point T by adding the leng th L of the transition curve tothe chainage of D.

9. If it is required to peg the points on through chainages, calculate the length of the sub-

chords and full-chords of the transition curves and the circular curve. The peg internal

for the transition curve may be 10 metres, while that for the circular curve, it may be 20

metres.

10. If the curves are to be set out by a theodolite, calculate the deflection angles for the

transition curve from the expression =RL

l2

573 minutes and the deflection angles


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(referred to the tangent at D) for the circular curve from the expression,

S = 1719R

Cminutes.

The total tangential angles N for the circular curve must be equal to (- 2s).


1. Transition curves are designed in the field in order to accomplish gradually the transition from

the tangent to the circular curve so that the curvature is increased gradually from zero to a

specified value.

2. To provide a medium for the gradual introduction or change of the required super-elevation.

Result:

Thus the setting out of transition curve is done.


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Ex.No: 16

Date:

FIELD OBSERVATION AND CALCULATION OF AZIMUTH

Reference mark:

In determining the azimuth of a star or the heavenly body it is necessary to have a referencemark (R.M.) or a referring object (R.O.). The reference mark may be a triangulationstation, or it may consist of a long tern or an electric light placed in a box or behind a screenin which a small circular aperture is cut to admit light t the observer. Sometimes a narrowvertical split is cut instead of a circular hole. For daytime observation the face of the screenis painted with stripes, or a target is painted on the side of the box towards the observer.The size of the apertures depends upon the distance of the mark from the instrument (9mmat a distance of 1 km). The reference embark should be, wherever possible, about 1 km away in order to obviate the necessity of refocusing the telescope in bisecting the mark

after bisection the star. It should be situated that the line of sight is well above the ground tominimize the error due to lateral refraction.

Observations for Azimuth in the field:

When determining the azimuth of a survey line, the process consists in (i) measuring thehorizontal angle between the reference mark and the heavenly (or celestial) body, and (ii)determining the azimuth of the celestial body. The azimuth of the reference mark may therebe calculate from the measured angle and the calculated azimuth of the celestial body. Theazimuth of a survey line may then be obtained by measuring the horizontal angle betweenthe mark and the line and combining it with the azimuth of the mark. Alternatively, if the

reference mark is the other end of the survey line, the azimuth of the line may bedetermined by measuring the horizontal angel between the line and celestial body andcombining it with the azimuth of the celestial body. There are several methods ofdetermining the azimuth of a line. But in practice, reference is given to such methods whichwill permit face left and face right observation to be taken in order to eliminate instrument alerrors, and which will also observation to be made at any time and with the requiredprecision. It is advisable to select a close circumpolar star, since such a star changes veryslowly in azimuth in a given length of time.

Aim:

To find the angle between the observed meridian and the vertical circle through the body.

General:

The required altitude and the horizontal angles are those to the suns centre. Hence the

hairs should be set tangential to the two limbs simultaneously. The opposite limbs are then

observed by changing the face as shown in figure.


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Procedure:

1. Set the instrument over the station mark and leveling very accurately.

2. Clamp both the plates to zero and sight the reference mark (RM).

3. Turn to the sun and observe and altitude and horizontal angle with the sun in quadrant 1

of the cross hair system.

4. The motion in the azimuth is slow and the vertical hair is kept in contact by the upper

tangent screw, the sun being allowed to make contact with the horizontal hair the line of

observation is also noted.

5. Using two tangential screw as quickly as possible, bring the sun in to the quadrant 3 of

the cross hairs and again read the horizontal and vertical angles. Observe also the

chronometer time.

6. Turn the RM. Reverse the face and take another side to RM.

7. Take two more observations of the sun precisely in the same way as in steps 3 and 4

above, but this time with the sun is quadrant 2 and 4. Note the time of each observations.

8. Finally bisect the RM to see that the reading is zero.During the above four observations (two with face left and two with face right)

One set of observations will be therefore, as under:

PointSighted

Position of the Sun Readings

RM

Sun Apparent right and upper limbs of the suntouches vertical and horizontal wires.

Horizontal reading to RM onface left

Horizontal & Vertical readings

to the sun on face left

Change face and swing the transit to get the sun in the field of view

Sun

RM Apparent left and lower limbs of the suntouches vertical and horizontal wires.

Horizontal and Verticalreadings to the sun on faceright

Horizontal reading to RM onface right.

Practical Application:

1. To find the True meridian of a survey line, determination of the azimuth of the line is

necessary.

Result:

Azimuth of the given line =

Note: For calculation of azimuth, refer standard text book.


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Face : Left Swing : Left

Inst at

Sight to

Horizontal angle Vertical angle Attitude Bubble Time

A B MeanIncluded

angleC D Mean

E O H M S

' '' ' '' ' '' ' '' ' '' ' ''

S Ref


S Ref


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Ex.No: 17Date:

STUDY OF ELECTRONIC TOTAL STATION

General:

A total station is an electronic/optical instrument used in modernsurveying.The total stationis an electronictheodolite (transit) integrated with an electronicdistance meter (EDM) toread distances from the instrument to a particular point. Some models include internalelectronic data storage to record distance, horizontal angle, and vertical angle measured,while other models are equipped to write these measurements to an externaldata collector,which is a hand-held computer.

Angles and distances are measured from the total station to points under survey, andthecoordinates (X, Y, and Z or northing, easting andelevation)of surveyed points relative tothe total station position are calculated usingtrigonometry andtriangulation.

Data can bedownloaded from the total station to a computer and application software usedto compute results and generate amap of the surveyedarea.

Most modern total station instruments measure anglesby means of electro-optical scanning of extremelyprecise digital bar-codes etched on rotating glasscylinders or discs within the instrument. The best qualitytotal stations are capable of measuring angles to 0.5arc-second. Inexpensive "construction grade" totalstations can generally measure angles to 5 or 10 arc-seconds.

Measurement of distance is accomplished with amodulatedmicrowave orinfrared carrier signal,generated by a small solid-state emitter within theinstrument's optical path, and reflected by a prismreflector or the object under survey. The modulationpattern in the returning signal is read and interpreted bythe computer in the total station. The distance isdetermined by emitting and receiving multiplefrequencies, and determining the integer numberofwavelengths to the target for eachfrequency. Total Station (Courtesy:Leica)

Most total stations use purpose-built glassPorro prism reflectors for the EDM signal. Atypical total station can measure distances with an accuracy of about 1.5 millimetres + 2parts per million over a distance of up to 1,500 metres.

Reflectorless total stations can measure distances to any object that is reasonably light incolor, to a few hundred meters.

Robotic total stations allow the operator to control the instrument from a distance viaremote control. This eliminates the need for an assistant staff member as the operator holdsthe reflector and controls the total station from the observed point.
http://en.wikipedia.org/wiki/Surveyinghttp://en.wikipedia.org/wiki/Theodolitehttp://en.wikipedia.org/wiki/Distancehttp://en.wikipedia.org/wiki/Data_loggerhttp://en.wikipedia.org/wiki/Coordinatehttp://en.wikipedia.org/wiki/Elevationhttp://en.wikipedia.org/wiki/Trigonometryhttp://en.wikipedia.org/wiki/Triangulationhttp://en.wikipedia.org/wiki/Downloadhttp://en.wikipedia.org/wiki/Maphttp://en.wikipedia.org/wiki/Microwavehttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Wavelengthshttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Porro_prismhttp://en.wikipedia.org/wiki/Robotichttp://en.wikipedia.org/wiki/Robotichttp://en.wikipedia.org/wiki/Porro_prismhttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Wavelengthshttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Microwavehttp://en.wikipedia.org/wiki/Maphttp://en.wikipedia.org/wiki/Downloadhttp://en.wikipedia.org/wiki/Triangulationhttp://en.wikipedia.org/wiki/Trigonometryhttp://en.wikipedia.org/wiki/Elevationhttp://en.wikipedia.org/wiki/Coordinatehttp://en.wikipedia.org/wiki/Data_loggerhttp://en.wikipedia.org/wiki/Distancehttp://en.wikipedia.org/wiki/Theodolitehttp://en.wikipedia.org/wiki/Surveying


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Smart Stations (Total station fitted with GPS)

With Smart Station you dont need to worry about control points, traverses and resections.Just set up wherever its convenient, touch the GPS key and let the Smart Antenna do therest. RTK determines the position to centimeter accuracy within a few seconds at ranges upto 50 km from a reference station. With Smart Station youre ready to go in the shortestpossible time; fix the position with GNSS/GPS and then survey with the total station.

GNSS/GPS -Integrated Total Station

With the entire software in the total station, all TPS and GNSS/GPS operations arecontrolled via the TPS keyboard. All data are stored in the same database on the sameCompact Flash card. All measurement, status and other information are displayed on theTPS screen. The TPS plug-in battery also powers the GNSS/GPS Smart Antenna and RTK

communication device. All components combine perfectly. Everything is integrated into onecompact unitno need for cables, external battery, data logger etc.

Smart Station (Cortesy:Leica)

ce6413 survey practical ii lab manual

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