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GUDLAVALLERU ENGINEERING COLLEGE Surveying Lab- I

Department of Civil Engineering Chain Survey Obstacles

SURVEYING FIELD WORK I LABORATORY

GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE: GUDLAVALLERU

DEPARTMENT OF CIVIL ENGINEERING

Name : ………………………………………………………

Regd. No : ……………………………………………………….

Year & Semester :………………………………………………………..

Academic Year : ……………………………………………………….



GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE::GUDLAVALLERU

DEPARTMENT

OF

CIVIL ENGINEERING

Surveying Field Work I- Lab Manual



GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE:: GUDLAVALLERU

DEPARTMENT OF CIVIL ENGINEERING

INDEX S.n

o Date

Name of the Experiment Signature

of the

faculty

1

2

3

4

5

6

7

8

9

10

11

12



CHAIN SURVEY OBSTACLES

AIM: To perform chain surveying across obstacles.

Equipment : 30 mts chain; Offset rod

Ranging rods; Field books

Cross staff; Arrows

Procedure and Principle:

The principle of chain survey is triangulation. Chain survey that type of surveying in

which only linear measurements are made in the field. This type of survey is most useful for

small areas or ground to take a sample details.

Procedure:

Before going to actual survey prepare enough idea in mind for locating main stations

and substations, then start actual survey by using 30 mts chain. We have an obstacle in

main survey line so we have to calculate the obstructed length. So we set out two sub help

of cosine rule calculations are done in this way. We calculate the obstructed length while

changing across of stable as pond.

Formula:

Cosine rule

PT2 = RR2 + TR2 – 2 PRTR cos θ

PQ2 = RR2 + RQ2 – 2 PR.RQ cos θ

Precautions:

1. Ranging rod should be ranged accurately.

2. Before starting the chain survey the chain length must be checked whether it is

accurate or not.

3. While changing across survey line chain must be held tightly. Loose in chain is

not permitted.

Result:

The length of A.D =

CHAIN SURVEY TRAVERSE



AIM: To determine the area by the chain survey.

Equipment: Ranging Rod: Chain or tape : offset rods, cross staff, arrows.

Formulas: Rectangular area A = b X h

Triangular area A = ½ X b X h

Trapezoidial area A = ½ X L [h1 + h2]

Procedure:

Set the two stations A and B. By ranging these two stations place the ranging rod or

intermediate points, Using intermediate points locate offsets for the ranging between A and

B. Measure the distance range by rotating the off set taken starting from A and B.

Join the offsets and ranging poles to get some required amount of triangles or

trapezoidal which enables to calculate given area.

Precautions:

1. It should be taken without parallax error.

2. Must and should be taken ranging offsets changing.

Result: Total area occupied =

CONTOURING



AIM: To plot the contours of a given area.

Apparatus: Dumpy level, chain, pegs, staff, tape etc.

Procedure:

Make the boundary of a given surface and plan divide the are a into number of

small squares or rectangles of 5 or 10 m width and mark the points. Now place the

boundary level such that all the readings can be taken. Adjust the dumpy levels having

necessary temporary adjustments such as eye piece, cross wires etc. Now place the

leveling staff at TBM and tabulates the B.S. continue the procedure of taking reading at all

the marked points.

Now change the station after few readings and continue the same process.

Calculate the R.L of all points. Draw the area of plane by making & all are using

necessary scales. Taking necessary contour intervals. Join the points which have same

R.Ls. Some R.L points can be obtained by measuring.

EX: A, B, C, D be quite points plotted on map having elevations.

Let AB = BC = CD = DA = 5 mts.

Locate the points on these using the vertical difference b/w these two points is the

difference of contours from B.

i) In this process points having some R.L s are marked.

ii) Join these points with smooth curves.

Precautions:

1. Dumpy level should have no errors.

2. Staff should be stand vertically.

FLY LEVELLING



AIM: To find the elevations of a given stations by rise and fall method .

Apparatus: Leveling staff, Tripod.

Theory:

The process of keeping height of instrument axis at differential levels and finding out

the reduced levels of the station is called the differential leveling.

Procedure:

Set up the level instrument at P (nearer to the temporary bench mark) as shown in

fig. and level the instrument roughly with the leveling screws. Till the circular bubbles

comes to the centre by using foot screws, till the bubble is in an exact coincidence.

Focus the eye piece through the point. The telescope towards the object and focus

the objective.

Focus the Telescope toward the temporary bench mark and bisect the staff correctly

and take the back sight as it and record the readings is leveling field book as shown in the

table.

Keep the leveling staff at the stations as intermediate sights and enter the readings

before shifting the instrument to the next station. The readings must be entered in the

foresight column in the field book. Shift the instrument to the next station and follow the

same procedure which you have done above.

` At the point F the staff is kept inverted position and at intermediate sight is taken and

enter the readings in the field book as negative. Lastly the survey is completed at the

beginning station of temporary bench mark calculation can be done by the height of the

instrument rise and fall.

Precautions:

1. The staff should held vertically when the reading is taken. The staff man should

be behind the staff.

2. While taking readings, always make sure that the bubble of the level is at the

centre.

3. Read the staff correctly, there should be no parallax error.

Result:

We obtained the R.L at required stations.

PLANE TABLE BY INTERSECTION



AIM: To plot the given area by methods of radiation by plane table.

Apparatus:

A plane table, alidade, plumbing fork or U. Frame and plumb bob, spirit level,

compass, drawing paper with a rain proof covers.

Theory:

A plane consists of a small drawing board mounted on a tripod thus the board can

be rotated about the vertical avis and can be clamped in any position on the table and

leveled by adjusting tripod legs.

Alidade:

A plane table alidade is a straight edge with some form of straight device. It

generally consists of a metal or wooden rule with two wanes at the ends. The two wanes

or sights are hunged to fold down on the rule when it is not in one of the wanes is provided

with a narrow slit while the other is open and carries a hair on the wire. Both the slits thus

provide a definite line of sight passes through the object to the sighted.

Plumbing fork:

The plumbing fork is used in large scale work. Its meant centering the table over a

point occupied by the plane table. It is meant for transferring the ground on the point on the

sheet. So that the plotted point on the ground station one in the same vertical line.

Spirit level:

A small spirit level may be used far ascertaining as if the table is properly level. The

table is leveled by placing the level on the board in two positions at right angles and getting

the bubble central in both positions.

Intersection:

Intersection is resolved when the distance between the point and instrument station

is either too large or can be measured accurately due to some field conditions the location

of a object is determined by sighting at the object

from the two plane table stations and drawing the rays. The intersection of rays will give

the position of the object. The distance between two instrument stations is measured and

plotted on the sheet.



Fix the table at point A, level the table with the help of plumb-bob and V frame with

the help of trough compass mark the distance in the board. Locate the point ‘A’ on it and

place the alidade about point ‘A’ and sight the point ‘B’. Measure the distance between A

and B and plot it on the board then draw A and B in direction AB. Pivot the alidade and

sight the stations C,D,E etc. and draw the corresponding rays along the alidade to intersect

the previously drawn rays. This method is mainly used for mapping.

Precautions:

1. Centering and leveling can be done carefully.

2. Ranging rods should be ranged accurately.

3. Vertical rods hair of the alidade may not be loose.

4. Alidade readings should be done carefully.

5. Rotating the instrument and plotting errors.

6. Chaining, measuring must be done without parallax error.

Result:

The given area is plotted by plane table by inter section method.



PLANE TABLE BY RADIATION

AIM: To plot the given area by methods of radiation by plane table.

Apparatus:

A plane table, alidade, plumbing fork or U. Frame and plumb bob, spirit level,

compass, drawing paper with a rain proof covers.

Theory:

A plane consists of a small drawing board mounted on a tripod thus the board can

be rotated about the vertical avis and can be clamped in any position on the table and

leveled by adjusting tripod legs.

Alidade:

A plane table alidade is a straight edge with some form of straight device. It

generally consists of a metal or wooden rule with two wanes at the ends. The two wanes

or sights are hunged to fold down on the rule when it is not in one of the wanes is provided

with a narrow slit while the other is open and carries a hair on the wire. Both the slits thus


Plumbing fork:

The plumbing fork is used in large scale work. Its meant centering the table over a

point occupied by the plane table. It is meant for transferring the ground on the point on the

sheet. So that the plotted point on the ground station one in the same vertical line.

Spirit level:

A small spirit level may be used far ascertaining as if the table is properly level. The


the bubble central in both positions.

Method of Radiation:

In the method of Radiation of plane table surveying we will draw radiating lines by

sighting the ranging rods at their respective positions on ground.

In this method, a ray is drawn from the instrument station towards the point, the

distance is measured between the instrument station and that point, and the point located

by plotting to some scale the distance so measured. Evidently, the method is more suitable

when the distances are small (within a tape length) and one single instrument can control



the points to be detailed. The method has a wider scope if the distances are obtained

tacheometrically with the help of telescopic alidade.

1. Set the table at T, level it and transfer the point on the sheet by, means of plumbing

fork, thus getting point t representing T. Clamp the table.

2. Keep the alidade touching t and sight to A. Draw the ray along the fiducial edge of the

alidade. Similarly, sight different points B,C,D,E etc., and draw the corresponding rays.

A pin may be kept touching the pin while sighting the points.

3. Measure TA,TB,TC, TD, TE etc., in the field and plot their distances to some scale along

the corresponding rays, thus getting a, b, c, d, e etc. Join these if needed.

Precautions:







Result:

The given area is plotted by plane table by inter section method.



PLANE TABLE TRAVERSE

AIM: To plot the given area by the method of traversing by plane table surveying.

Instruments:

A plane table, alidade, plumbing fork and plumb-bob, spirit level, compass, drawing

paper with a rain proof cover.

Theory:

A plane table consists of a small drawing board mounted on a tripod. Thus the

board can be rotated about the vertical axis and can be clamped in any position the table is

leveled by adjusting the tripod legs.

Alidade:

A plane table alidade is a straight edge with some form of sighting. It generally

consists of a metal or wooden rule with two vanes at the ends. The two vanes or sights are

hanged to fold down on the rule when it is not in use. One of the vane is provided with a

hallow slit, while the other is open and carries a hair or a thin wire. Both the slits thus


Plumbing Fork:

It is used in large scale work. It is meant for centering the table over a point

occupied by the plane table. It is meant for transferring the ground point on to the sheet.

So that the plotted point and ground station are in the same vertical line.

Spirit level:

A small spirit level may be used for ascertaining as if the table is properly level. The


the bubble at central in both positions.

Plane table traverse involves the same principle as a transit traverse at each

successive stations. The table is set, a fore sight is taken to the focusing station. As in the

radiation method described earlier. In plane table traverse, the

table is set at each successive stations, a fore sight is taken to the next station and its

location is plotted on the foresight, by measuring the distance directly between the two

stations. This method is widely used to lay down the survey lines between the instrument

stations of a closed or unclosed traverse.

Procedure:



1. Set the table at A use plumbing fork for transferring A on to the sheet. Draw the

direction of magnetic meridian with help of trough compass.

2. With the alidade pivoted about A sight to B and draw the ray, measure AB and

scale (a b) to some scale. Similarly draw a ray towards E measure AE and plot to

same scale used earlier.

3. Shift the table to B and set it to the table accurately by back sighting A clamp on

the table.

4. Pivoting the alidade about ‘b’, sight to C measure BC and plot it on the ray drawn

to the same scale. Simultaneously the table can be set at other stations and the

traverse is completed.

Precautions:

1. Centering and leveling should be done carefully.


3. Vertical hair of the alidade may not be loose.

4. Alidade readings should be carefully noted.

5. Rectify the instrument and plotting errors.

6. Weighing, measuring should be done with out any parallax error.

Result:

The area of traversing by plane table surveying is _________ m2.



PROFILE AND CROSS SECTIONAL LEVELLING AIM: To plot the features of the given area by longitude section (L.S) and cross section

leveling.

Apparatus:

Ranging rods, leveling staff, tripod, chain, cross staff dumpy level, auto level etc.

Theory:

1) Longitudinal Section: To find out the elevations of the ground a long a fixed

line. The fixed line is generally to the central line of high way and railway track.

2) Cross Sectional leveling: C.S are run at right angles to the lived line, along

which longitudinal section is done. The solutions are taken on either side of the

fixed line. To obtain the lateral out line of the ground surface.

Procedure:

1. Fix the line AB along with profile. Leveling is to be done.

2. Mark of the Intermediate stations a, b,c etc on the fixed line at a interval of 6 mts.

3. The instrument is set up temporarily adjustments and positions and intermediate

points are located by chaining along the fixed line AB and noting the distances

from starting station.

4. Set the instrument at a point L so as command a large number of points on the

fixed line.

5. A,B.S is taken on the temporary B.M to determine the H.I or rail C and fall of

ground level.

6. Establish a right angle line of a station A on either side of the fixed line with the

help of cross staff.

7. By placing the leveling staff of a spacing 1 mt and 3 mts on either side of the

fixed line and the corresponding R.L.S are noted into the field book.



Precautions:

1. The staff should be held vertically when the reading is taken and the staff should

be behind the staff.

2. While taking readings always make sure that the bubble of the tube is in central.

3. Read the staff reading without any parallax error.



SURVEYING AN AREA BY CLOSED TRAVERSE

AIM: To survey an area by prismatic compass and plotting after adjustment.

Equipment:

30 mts chain; ranging rods; off sets; pegs prismatic compass, tripod, field

books, arrows etc.

Theory:

The principle of compass traversing is it contains a magnetic meddle and divided

into degree and half degrees. The graduations start from N=1800, S=00, E=900, W=270 Eye

wane and object wane passes through the centers of the prism. A glass cover is provided

at the top. So that dust particles cannot enter into compass box. A mirror is provided to

measure too low or too far objects.

Centering:

A tripod is placed over the station with its legs spread well apart so that it is at a

workable height. The compass is fixed on the tripod. It is then centered over the station

where the bearing is to be take (i.e) centre of the compass the pivots brought exactly below

the ground station. A plumb is bob is not provided a stone is dropped below the compass

and it should fall on the peg marking in the ground station.

Leveling:

The compass is leveled by the eye-judgment this is essential so that the graduated

ring springs freely. Some times two plate levels are at right angles and also provided to

level the instrument. The leveling is achieved by a ball and socket adjustments which is

adjusted till the bubbles concentrated in both the plate levels.

Local attraction:

The magnetic needle does not point to the magnetic north, when it is under the

influence of the external attractive forces in the presence of magnetic materials, such as

iron pipes, iron lamps, steel structures, rails cables chain, arrows, mineral deposits in the

ground etc. The needle is deflected from the

normal position hence the local attraction by the magnetic materials. Needle of the

compass the amount of deviation of the magnetic needle is the measured of the local

attraction.

Procedure:



1. Select the building or area to be plotted.

2. Mark the corners of the given area to the plotted.

3. Take the convenient points A1,B1,C1 and D1around the building for measuring the

corners of the building.

4. The points A1,B1,C1, D1 are selected in such away that from every point both pole

bearing FB and back bearing BB should be taken.

5. Fix the prismatic compass at a station A and measure the distance b/w A and

A1and recording the bearing at AA1.

6. From A1 right B1and record the bearing of the line A1B1 with same adjustment of

the instrument sight D1 and A1 and record B. B of line D1 A1.

7. Shift the instrument station from A1 and B1 sight C1 and record FB.

8. Eliminate local attraction.

Precautions:


2. Magnetic needle should be perfectly straight.

3. Vertical hair of the compass should not be loose.

4. Eye wane and object wane should be vertical.

5. Chaining, reducing, measuring, leveling and centering should be done without

any parallax error.

Result:

Surveying of an area by closed traverse is done.



The Three – Point Problem

AIM: To plot the given point is by three point problem method by plane table surveying.

Instruments:



Theory:

The three-point problem is also a problem of resection. The objective is to obtain the

position of the station occupied by the table after orientation. The three-point problem can

be stated s follows: Given three visible stations and their plotted positions, to plot the

station occupied by the plane table with the table correctly oriented with respect to the three

points already plotted.

The three – point problem can be solved using many methods. The following three

methods will be discussed here:

1. tracing paper method

2. graphical method

3. trial and error method

Tracing Paper Method:

The following procedure is adopted (refer to below figure) in this method.

1. Let P,Q, and R be the three stations whose plotted positions p, q, and r are available on

the plan. Let S be the station where the plane table is to be set up. The objective is to

orient the table with respect to P, Q and R and then plot the position of S.

2. Set up the plane table at S and level it. Fix the sheet with the plotted positions of P, Q

and R on the table. Rotate the table and approximately orient it visually so that A-B or B-C

is parallel to a-b or b-c.

3. Fix a tracing paper on the table over the sheet. Mark the position of S on the tracing

sheet as s1 using a plumbing fork. This is only approximate, as the table is not oriented.

4. With the alidade centered on s1, sight the signals at P, Q, and R and draw rays s1p1,

s1q1, and s1r1. These rays will not pass through the point p, q, and r plotted earlier, as the

orientation is only approximate.



5. Loosen the tracing paper from the table. Rotate the tracing paper so that rays s1p1, s1q1

and s1 r1 pass through p, q, and r. Fixing the sheet in such a position, transfer the position

of s1 to the drawing sheet as s.

6. Remove the tracing paper. Place the alidade along s-p. It will not pass through the

signal at P, as the table is not oriented. Rotate the table so that the signal at P is sighted

when the alidade is kept along s-p and clamp it. The table is now oriented.

7. Check the orientation by sighting the signals at Q and R by placing the alidade along s-q

and s-r, respectively. If the orientation is correct, these signals must be seen in these

positions.

Precautions:







Result:

The given point is plotted by plane table by three point problem method.



The Two-point Problem AIM: To plot the given point by the two point problem by plane table surveying.

Instruments:



Theory:

The two-point problem is a special case of resection to obtain the position of the station

occupied by the table, given the plotted position of two points. The two-point problem can

be stated follows: To determine the position, s, of the station S occupied by the plane

table, given the accurately plotted positions, p and q, of two points, P and Q, visible from

the instrument station and without occupying these two stations.

Figure below shows the problem. P and Q are two survey stations which have been

surveyed earlier and their positions plotted as p and q on the sheet. S is the instrument

station (where the plane table is to be set up) and it is required to get the position of S on

the sheet as s when the table is oriented correctly, i.e., when P-Q is parallel to p-q. The

following procedure can be adopted to solve the two-point problem.



1. Select an auxiliary station R such that the signals at P,Q and S are clearly visible from R

and the angles formed by P,Q and S are not very acute.

2. Set up the plane table at R. Level the table. Approximately orient the table so that p-q

is nearly parallel to P-Q. Clamp the table in this position.

3. Plot the position of R on the table by sighting to P and Q. For this, keep the alidade

against p and sight the signal at P. Draw a line along the ruling edge of the alidade.

Similarly, sight the signal at Q by pivoting the alidade against q and draw a ray. The

intersection of the two rays drawn gives the position of the station occupied by the table.

Label this point r. Point r is obtained as the position of the station occupied and is

accurate to the extent the line p-q is parallel to P-Q.

4. Transfer the point r on the table to the ground as R using the plumbing fork. A peg can

be driven to locate the ground station.

5. With the alidade kept against r, sight the ranging rod or other signal at S and draw a

line. Mark the distance S by approximation or rough chaining. Point s1 is thus obtained.

6. Shift the table to S. Level and centre the table over s1. Orient the table by back sighting

at R. For this, keep the alidade against s1. and sight the signal at R by rotating the

table. Clamp the table in this position.

7. With the alidade kept against p, sight the station P and draw a ray. This ray intersects

the line r-s at s, giving the station s. Keep the alidade against s, sight the signal at Q,

and draw a ray. This ray will intersect the ray r-q not at q but at q’, as the orientation of

the table is only approximate.

8. p-q’ is the representation obtained of p-q due to the error in orientation. The angle q-p-

q’ is the angular error in orientation.

9. To remove this error, place the alidade against p-q’ and keep a ranging a rod at a large

distance M.

10. Keep the alidade against p-q and rotate the table until the signal at M is sighted and

clamp the table. This position is the correct oriented position, with P-Q parallel to p-q.

11.Obtain the position of S by sighting P and draw a ray. Keep the alidade against q and

sight the signal at Q. The intersection of the two rays gives the true position, s, of S.

The distance of M must be large enough to correct the orientation of the table.



Precautions:







Result:

The given point is plotted by plane table by two point problem method.



TO CALCULATE THE DISTANCE BETWEEN TWO IN ACCESSIBLE POINTS.

AIM: To determine the distance between two in accessible points with compass.

Equipments Used:

30 mts chain; ranging rod; cross staff, off sets: Prismatic compass Tripod: Field

book; arrows.

Theory:

1. The principle of compass traversing is it contains a magnetic needle and

dividing into degrees and half degree graduations starts from N=1800

= O0 E = 900 W=2700.

2. Eye wane and object wane passes through the centre of prism. A glass

cover is provided into the compass box. Incline mirror is provided to

measure too low or too tall of objects.

Centering:

A tripod is placed over the stations with its legs, spread with a part. So that it is a

workable height. The compass is firmed on the tripod. It is the centre over the station

where the bearing is to be taken (i.e) the centre of the compass pivot is brought exactly

above the ground station. A plumb bob is hung from the centre of compass. In case of

arrangement of work plumb bob is not provided as stone is should flow on the peg working

the ground station.

Leveling:

The compass is leveled by high judgment. This is essential so that the graduated

ring swings freely. Some times, in surveys compass two plate levels at right angles are

also provided to level the instrument. The leveling is achieved by a ball and socket

arrangement which is adjusted till the bubbles becomes centre in both the plane levels.

Local attraction:

The magnetic needle does not point to the north when it is under the influence of the

external attractive forces in the presence of magnetic material such as iron pipes, Iron

lamps, steel structures, Iron lamps, rails cables, chain arrows, mineral deposits in ground

etc. The needle is deflected from its (ground) normal



position. Hence local attraction by the magnetic materials is disturbing influence on the

magnetic needle.

Procedure:

Let P and Q are the two points and there is an obstacle between them. Now we

have to measure the distance between P and Q by compass. Select two points A and B

such that line AB is almost perpendicular to the line PQ and the distance between A and B

is measured with a chain.

Place the compass and station a centering and levelly with centre A. Note the

readings of AP, AQ and AB then shift the compass to stations B after centering and leveling

its place the bearing of BA, BP and BQ.

Cosine rule

PQ2 = PA2 + AQ2 – 2 PA.AQ cos(PAQ)

From ∆ APB sine rule.

AB = PA from ∆ABQ AB = AQ

Sin P Sin B SinQ SinB

Precductions:

1. Ranging rod should be ranged accurately.

2. Magnetic needle should be perfectly straight.

3. Vertical hair of the compass may not be loose eye wave and direct wave should

be vertical changing, reading, measuring, leveling and centering should be done

without parallax error.

Result:

The distance between in accessible points is ___________.

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