ABSTRACT

The camp was held at Kunnavakkam village near Jeppiar steel plant, Panruti post, Kancheepuram District. The camp took place for a period of 5 days in Kunnavakkam village. We learnt to find the area of the given place by Triangulation and Trilateration, Longitudinal section and Cross section of a proposed roadway, level of a large area by Grid contouring and radial contouring and the use of Total Station to find the given area. All the experiments were performed at Kunnavakkam village. The area was nearly 100 acres and hence no difficulty was faced by us to perform the experiments.

CONTENTS EX.NO NAME OF THE EXPERIMENT 1. TRIANGULATION 2. TRILATERATION 3. GRID CONTOURING 4. RADIAL CONTOURING 5. TOTAL STATION

PAGE NO

TRIANGULATION AND TRILATERATION The method of surveying called triangulation is based on the trigonometric proposition that if one side and two angles of a triangle are known, the remaining sides can be computed. The vertices of the triangles are known as triangulation stations. The side of the triangle, whose length is predetermined, is called the base line. A triangulation system also consists of a series of joined or overlapping triangles. However, for trilateration the lengths of all the sides of the triangle are measured and few directions or angles are measured to establish azimuth. Trilateration has become feasible with the development of electronic distance measuring (EDM) equipment which has made possible the measurement of all lengths with high order of accuracy under almost all field conditions.

OBJECTIVE OF TRIANGULATION AND TRILATERATION SURVEYS The main objective of triangulation or trilateration surveys is to provide a number of stations whose relative and absolute positions, horizontal as well as vertical, are accurately established. More detailed location or engineering survey is then carried out from these stations. The triangulation surveys are carried out  To establish accurate control for plane and geodetic surveys of large areas, by terrestrial methods,  To establish accurate control for photogrammetric surveys of large areas,  To assist in the determination of the size and shape of the earth by making observations for Latitude, longitude and gravity.

CLASSIFICATION OF TRIANGULATION AND TRILATERATION SYSTEM  First order: Determine the shape and size of the earth or to cover a vast area  Second order: This consists of a network within a first order triangulation.

 Third order: It is a framework fixed within and connected to a second order triangulation system to immediate control for locating surveys.

LAYOUT FOR TRIANGULATION: The triangles in a triangulation system can be arranged in a number of ways.    

Single chain of triangles Double chain of triangles Braced quadrilaterals Centered triangles and polygons

Single chain of triangles: When the control points are required to be established in a narrow strip of terrain such as a valley between ridges, a layout consisting of single chain of triangles. It does not involve observations of long diagonals. This system does not provide any check on the accuracy of observations.

Braced quadrilaterals: A triangulation system consisting of figures containing four corner stations and observed diagonals. This system is treated to be the strongest and the best arrangement of triangles, and it provides a means of computing the lengths of the sides using different combinations of sides and angles.

Double chain of triangles: This arrangement is used for covering the larger width of a belt. This system also has disadvantages of single chain of triangles system.

Centered triangles and polygons: A triangulation system which consists of figures containing interior stations in triangle and polygon is known as centered triangles and polygons. Though this system provides checks on the accuracy of the work, generally it is not as strong as the braced quadrilateral arrangement. Moreover, the progress of work is quite slow due to the fact that more settings of the instrument are required.

EX. NO. 01 DETERMINATION OF AREA BY TRIANGULATION METHOD AIM: To determine the area of the given plot using the method of triangulation.

DESCRIPTION: Triangulation is the process of establishing horizontal control in the surveying. The triangulation system consist of number of inter connected triangles in which the length of the base line and the triangle are measured very precisely.

EQUIPMENTS REQUIRED:    

Theodolite with tripod stand Ranging rod Tape Arrow

FORMULA USED: Sine formula:

For calculating the sides of a triangle,

AB2 = AC2 + BC2 – 2*AC*BC*cosθ Θ is the angle between ACB

TO FIND AREA: A=√ ( (

s=

)(

)(

)

)

, a, b and c sides of a triangle

PROCEDURE:  The base line is selected and marked as P and Q at 25m distance apart.  The other station points namely A,B,C,D where selected around the base line PQ  Ranging rods are fixed at each point and now the instrument is placed over the station P and all other adjustments were made  Then from P the ranging rod at the station Q is sighted and angles were noted keeping the instrument.  At face left similarly from station P all the other points were sighted and the angles were measured. After that the angles were noted by changing the face of the instrument to face right.  Then the instrument is shifted to station Q and the initial adjustments are done.  Repeat the same procedure carried out at the station P and the angles were recorded.  The interior angles were calculated and drawings are drawn. Area are calculated using the formula

DATE BATCH NO TITLE STAFF NAME INSTRUMENT NO

Face left swing right A B mean * ‘ ‘’ “ ‘ “ * ‘

Instrument Sight sight to

S1

S2

S3

DETERMINATION OF AREA BY SIMPLE TRIANGULATION METHOD

Face right swing left Total mean A B mean “ * ‘ “ * ‘ “ * * ‘ “

A B S2 G H S1 B C S3 F G S2 C D

CALCULATION: IN TRIANGLE S1S2B:

s=

(

)

BS2 =

m

Sb1 =

m

A=√ (

)(

)(

) =

m2

IN TRIANGLE S2S3C:

CS2 = 80.23m CS3 = (

)

s= A=√ (

m

)(

)(

) =

m2

) =

m2

) =

m2

IN TRIANGLE S1S2G:

GS1 =

m

GS2 =

m

(

)

s= A=√ (

)(

)(

IN TRIANGLE S2S3F:

FS2 =

m

FS3 =

m

(

s= A=√ (

)(

)

)(

IN TRIANGLE BS2C: BC2 = BS22 + CS22 – 2*BS2 * CS2 COSθ BC2 = (

)

s= A=√ (

)(

=

m

)(

) =

=

m

m2

IN TRIANGLE S2GF: GF2 = FS22 + GS22 – 2*FS2 * CS2 COSθ GF2 = (

s= A=√ (

)(

)

)(

) =

m2

IN TRIANGLE S1GH: GH2 = HS12 + GS12 – 2*HS1 * GS1 COSθ GH2 = (

s= A=√ (

)(

)

=

)(

m ) =

m2

IN TRIANGLE S1AB: AB2 = AS12 + BS12 – 2*AS1 * BS1 COSθ AB2 = (

)

s= A=√ (

)(

=

m

)(

) =

m2

IN TRIANGULE S1AH: AS1= 30m HS1= 52.5m (

s= A=√ (

)(

)

=

)(

m ) =

TOTAL AREA = 1+2+3+4+5+6++7+8+9 (TRIANGLE VALUE) TOTAL AREA =

m2

The area of the given plot =

m2

RESULT:

m2

EX. NO. 02 DETERMINATION OF AREA BY TRILATERATION METHOD AIM: To determine the distance between the given station points using the method of trilateration and area enclosed by the station points.

DESCRIPTION: Trilateration is the method of calculating the distance between the station points by running a closed traverse

EQUIPMENT REQUIRED:      

Theodolite Ranging rod Leveling staff Cross staff Arrows Pegs

FORMULA USED: Horizontal distance D = KS COS2θ + C COSθ K = multiple constants =100 C= additive constants = 0 S = staff intercept (top hair – bottom hair)

AREA OF THE TRIANGLE: A=√ (

)(

)(

(

)s =

)

, a, b and c sides of a triangle

PROCEDURE:  Mark the given points A,B,C,D,E,… by using peg or arrows in such a way that it is possible to see those points from any point  Then the instrument is placed in such a way that it is centre to all the points and also visible from the selected points.  The initial adjustment are done for accuracy in the survey  Then the point A is forced and then the vertical angle and the top, middle and top hair readings are taken by placing the leveling staff at point A.  The vertical and the top, middle and the top hair reading are taken for all the given points  Then the instruments is set any point and the distance and the vertical angle between the adjacent points are taken  Thus we get a polygon whose sides are known or multiple triangle whose sides are drawn  By using the given dimensions and by using the triangle formulas the area can be calculated.

TABULATION: DATE BATCH NO EXERCISE DETERMINATION OF AREA BY TRILATERATION METHOD STAFF NAME INSTRUMENT NO STADIA HAIR READING STATION SIGHT VERTICAL VERTICAL ANGLE PT TO POINT TOP MIDDLE BOTTOM A B C O D E F B A F D E F D C B

CALCULATION: Horizontal distance = KS COS2θ + C COSθ Where C=0 OA = KS COS2θ + C COSθ OA= OB= KS COS2θ + C COSθ

OB= OC = KS COS2θ + C COSθ OC= OD = KS COS2θ + C COSθ OD= OE = KS COS2θ + C COSθ OE= OF= KS COS2θ + C COSθ OF= AB= KS COS2θ + C COSθ AB= AF = KS COS2θ + C COSθ AF= ED = KS COS2θ + C COSθ ED=

EF = KS COS2θ + C COSθ EF = CD = KS COS2θ + C COSθ CD= CB = KS COS2θ + C COSθ CB=

TO FIND THE AREA: IN TRIANGLE AOB: A=√ ( (

s=

)( )

)(

)=

)(

)=

)(

)=

=

IN TRIANGLE BOC: A=√ ( (

s=

)( )

=

IN TRIANGLE COD: A=√ (

)(

(

s=

)

=

IN TRIANGLE DOE: A=√ ( (

s=

)( )

)(

)=

)(

)=

)(

)=

=

IN TRIANGLE EOF: A=√ ( (

s=

)( )

=

IN TRIANGLE AOF: A=√ ( (

s=

)( )

=

TOATAL AREA = A1 +A2 + A3 + A4+ A5 +A6 A=

RESULT:

The area of the given plot is

m2

EX. NO.03 CONTOURING Contour lines are imaginary line on the ground joining the points of equal elevation. It is a line in which the surface of ground is intersected by a level surface. CONTOUR INTERVAL: The vertical distances between two consecutive contours are called as contour interval. The contour interval is kept constant for a contour plan, otherwise the general appearance of the map will be misreading.    

Nature of the ground The scale of the map Purpose and extend of the survey Time and expense of field and office work

CHARACTERISTICS OF CONTOUR: The following characteristics features may be used while plotting or reading a contour plan or topographic map.  Two contour lines of different elevations can write to form one line only in the case of a vertical cliff.  Contour lines close together indicate steep slope. They indicate a gentle slope if they are far apart.  A contour passing through any point is perpendicular to the line of steepest slope at that point.  A closed contour line with one or more higher ones inside and it represents a hill.  Two contour lines having the same elevation cannot write and continue split into two lines.  A contour line must close upon itself, not necessarily within the limits of the map.  Contour lines cross a watershed or ridge line at right angles.

 Contour lines close a valley line of right angles.

Methods of locating contours: a) The direct method b) The indirect method

(a) The direct method: As in the indirect method, each contour is located by determining the positions of a series of points through which the contour passes. The operation is also sometimes called tracing out contours. The field work is two-fold. 1. Vertical control : 2. Horizontal control :

Location of points on contour Survey of those points

(b) The indirect method: In this method, some guide points are selected along a system of straight lines and their elevations are found. The points are taken plotted and contours are drawn by interpolation. These guide points are not except by coincidence. The following are some of the indirect method of locating the ground points. 1) By squares 2) By cross sections 3) Tachometric method

EX.NO.04 (a) GRID CONTOURING AIM: To draw the contour map for the given area

DESCRIPTION: A map without relief representation is simply a plan on which relative positions of details are only shown in horizontal phase. Relative heights of various points on the map may be represented by one of the methods of contour.

SQUARE METHOD: It is the indirect method of contouring. Here the entire area is divided into number of square sides which may vary from 4m-48m, depending upon nature of the ground, the contour interval and the scale of the plan.

EQUIPMENTS REQUIRED:      

Theodolite with tripod stand Ranging rod Leveling staff Arrows

Cross staff Tape or chain

PROCEDURE:  The site for block countering is selected by through study. The dimension of block counter size is selected accordingly.  Then the area is divided into blocks of the size 3m*3m by using cross staff, chain and ranging rod.

 The instrument is placed in such a place where maximum reading can be taken on the intersection points  Readings taken at the intersection points are entered in the field book.  Change points are provided wherever needed. After taking the readings, the RL of each point is calculated by height of collimation method or by rise and fall method.  All reduced levels are plotted in A2 drawing sheet of suitable scale. The points having same reduced levels are connected and finally we observe a contour map. The contour of the desired values in interpolated.

DATE BATCH NO. TILTE GRID CONTOURING STAFF NAME INSTRUMENT NO.

STATION 0,0 5,0 10,0 15,0 20,0 25,0 30,0 0,5 5,5 10,5 15,5 20,5 25,5 30,5 0,10 5,10 10,10 15,10 20,10

X 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20

Y 0 0 0 0 0 0 0 5 5 5 5 5 5 5 10 10 10 10 10

B.S

I.S

F.S

H.I

R.L

REMARKS

25,10 30,10 0,15 5,15 10,15 15,15 20,15 25,15 30,15 0,20 5,20 10,20 15,20 20,20 25,20 30,20 0,25 5,25 10,25 15,25 20,25 25,25 30,25 0,30 5,30 10,30 15,30 20,30 25,30 30,30

25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30

10 10 15 15 15 15 15 15 15 20 20 20 20 20 20 20 25 25 25 25 25 25 25 30 30 30 30 30 30 30

RESULT:

The block size of 3m*3m was drawn and reduced level at each intersection was entered. Smooth curves of various lines were drawn connecting points of equal elevation and the contour map was prepared.

EX.NO.04 (b) CONTOURING – RADIAL CONTOURING AIM: To prepare contour map for the given area.

INSTRUMENTS REQUIRED: 1. Theodolite 2. Ranging rod 3. Chains 4. Arrows 5. Pegs

PRINCIPLE: This method is suitable for countering the area of long strip undulations where direct chaining is difficult.

FORMULA USED: Reduced level of the instrument = Bench mark + staff reading on bench mark – Height of Instrument Horizontal distance=D=KS cos2 θ +cos θ S=staff intercept Vertical distance=D tan θ Reduced level of any point= Reduced level of the instrument-- staff reading Vertical distance

PROCEDURE:  Range out the radial line from a common centre at known angular interval.  Fix arrows on the radial lines at equal distances of 3m or 5m.  Set up the instrument at any convenient place to cover the maximum points.  Hold the leveling staff in the place of arrows.  Note down the vertical angels and the hair readings and enter it correctly.  Repeat the same procedure for other radial lines.  Similarly shift the instrument s tat ion to other convenient place and c over the entire area.

OBSERVATION AND TABULATION BATCH NO TITLE

RADIAL CONTOURING

STAFF NAME INSTRUMENT NO

Instrument AT

Bearing in Degree

0 O

30°

Sight Horisontal To Distance

B.S

I.S

F.S

H.I

R.L

Remarks

100

B.M

60°

O 90°

120° 1500

2400

2700 .

3000

3300

3600

RESULT:

The block size of 3mx3m was drawn and reduced level at each intersection was entered. Smooth curves of various lines were drawn connecting point of equal elevation and the contour map was prepared.

TOTAL STATION INTRODUTION: Total station is an electronic/ optical instrument mainly applied in constrution and civil engineering field. Angles, distance, coordinates and many advanced measurement are accomplied by using trigonometry and triangulation. Downloading and uploading data are available.

PURPOSE AND USES:  Large and high resolution screen guarantees a clear display  Measure up to 100m in the reflector less mode  Extended internal memory accepts up to 50000 point  Handly EDM head  Electronic auto compensator  Equipped with advanced measurement programs and practical software  Possibility of red laser centering  Red laser directing ensures pinpoint accuracy in reflector less measurement  Easy and directoperation with the alphanumeric keyboard and the function keys  Long battery life up to 30 hours for angle measurement only  Rugged,durrable, water and dust resistant design  Technical specifications.

ANGLE MEASUREMENT (HZ.V) Accuracy 5" Method grating disk Min. reading 1" Standard deviation 2" Compensation vertical axis Compensating range ±3'

Level parameter: Circular level 8'/2mm Plate level 30"/2mm

TELESCOPE Magnification 30x Image erect Field of view 10 30'(2.6%) Min. focus 1.5m Optical aperture 45mm Length of sleeve 150mm Resolution 3" Distance of circles 71mm

DISTANCE MEASUREMENT 

Min. reading 1 mm

Reflector: Measurement range (good condition) Single prism 4000m Triple prism 7000m Measurement accuracy ± (3+2ppm.D) mm

Measurement time:  Fine measurement mode (repeat) about 1.8 sec (first time 2.5 sec)  Tracking measurement mode about 0.4 sec (first time 1.5 sec) Atmospheric correction:  

-

1ppm) -

Reflector less:  Measurement range (Kodak white) 100m  Measurement accuracy ±5mm Measurement time:  Fine measurement mode (repeat) about 1.8 sec (first time 3 sec)  Tracking measurement mode about 0.5 sec (first time 2 sec) DISPLAY:  Screen type 4-line dot matrix LCD with backlight  Display unit Double sides

PHYSICAL SPECIFICATIONS Battery power: Voltage DC 7.2V Capacity: Distance and angle Measurement Angle measurement Lithium battery BDC 40L 4.0AH 4.5h 30h Temperature -200c Dimension: 190mmx210mmx350mm Net weight: 0.6Kg

OTHERS Interface RS 232C Water proof /dust proof protection IP54

Standard specifications: Main unit

1

Software

2

RS 232 data Cable

1

Rechargeable battery

2

Battery charger

1

Car charger

1

Tool kit

1

Dryer

1

Lint- free cloth

1

Brush

1

Screwdriver

1

Rain protector

1

GRAPHICAL VIEW:

EX.NO.05

DETERMINATION OF AREA BY USING TOTAL STATION

AIM: To determine the area of the polygon by using total station.

APPARATUS REQUIRED:    

Total station Prism Stand Prism stand

DESCRIPTION: It is electronic instrument that has a large accuracy and are mostly preferred in large projects. It is less time consuming and overcomes human errors over a great extent making things easier.

PROCEDURE:  Select the suitable station point such that all the point of the polygon is visible clearly  Place the total station and level it and center point of the station is noted  Take the reference point and set the co ordinate (0,0,and 0)  Place the prism on the first point and focus it and measure it for getting coordinate of that point  Similarly, get the coordinate of different points of the polygon

 Finally, place the prism at the first point and measure it for complete closed polygon  Go to graphical view and see the polygon  Go to calculation 2d area and get area of the polygon.

STEPS TO BE FOLLOWED: FLOW CHART Level it

Change it made B

Set the coordinate (0, 0, 0) on reference point

Place the prism at point

Focus it and measure

Similarly for all the point and get coordinates

Finally, place the prism at first point for closed polygon

Calculation 2D area

DATE BATCH NO TITLE

TOTAL STATION

STAFF NAME INSTRUMENT NO P.N

P.C

X-AXIS

Y-AXIS

AREA OF THE CONTOUR =

Z-AXIS

RESULT:

The area of the given plot is

m2