Surveying Full Notes

#. surveying :- surveying is the art of determining the relative position of distinctive feature on
the surface of the earth or beneath the surface of the earth, by means of measurement of
distance, direction and elevation.
#. Objective of surveying
- The aim of surveying is to prepare a map to show the relative position of the object on
the surface of the earth.
- To analyze and calculate the field parameter for setting out operation of actual
engineering works.
- To set out the field parameters at the site for further engineering works.
- To determine the distance and angle between different objects.
- To solve measurement problem in optimum always.
- To prepare plan or map of the area surveyed.
#. Classification (primary division of survey)
1. Plane surveying
2. Geodetic surveying
#. Plane surveying :- the survey in which earth surface is assumed as a plane and curvature of
the earth is ignored, are known as plane survey.
- Area up to 260km2
- Lines connecting between two points are considered as straight lines.
- And angle between lines considered as plane angle.
- Knowledge of plane geometry and trigonometry is required.
- It is generally done on large scale.
- Plane survey are used for the layout of highway, railways, canals, fixing boundaries
pillars, construction of bridges, factories etc.
#. Geodetic surveying :- the survey in which curvature of earth is taken into account and higher
degree of accuracy in linear as well as angular observations is achieved are known as geodetic
survey.
- Area more than >260km2
- Small scale
- Précised instrument and methods are used.
- Lines connecting any two points are considered as arch.
- And angles as spherical angle
- Knowledge of spherical geometry is required.
- Generally done by department of survey.
Note:-
• The difference in length between the arch and its subtended chord on the earth
surface for a distance of 18.2 km is only 0.1m

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 • The difference between the sum of angle of spherical triangle having an area of 200
km2on the earth surface and that of corresponding angle of the plane triangle is only
1 sec. it is also known as spherical excess.
#. Classification of surveying
- Based upon nature of the field
1. land survey:- carried out on the earth (no water bodies)
a). topographic survey :- they are used to indicate the natural features such as mountainous
terrain, rivers, waterbodies wooded area and other cultural details such as roads, railways,
township etc.
b). cadastral survey :- these are carried out for fixing the property lines, calculation of area
landed properties and preparation of revenue maps of states are called cadastral survey.
- these are also sometimes used for surveying the boundaries of municipalities corporation and
cantonment.
- these are plotted on larger scale than topographic survey.
c). city survey :- the survey which are carried out for the construction of roads, parks, water
supply system, sewer and other constructional works for any developing township are called
city survey.
- the city map prepared for the tourist are known as guide map.
2. hydrographic survey:- the survey which deal with the mapping of large water bodies for the
purpose of navigation, construction of harbor works, prediction of tides and determining the
mean sea level are called hydrographic survey.
- it consists of preparation of topographical maps of the shores and banks.
3. Astronomical survey :- the survey which are carried out for determining the absolute
locations i.e., latitude of different places on the earth surface and the direction of any line on
the surface of the earth by making observation to heavenly bodies i.e., stars and sun, are called
astronomical survey. In northern hemisphere, when night observation are preferred to ,
observation are usually made to Polaris. i.e., the pole star.
#. Classification based on the purpose of survey
1. engineering survey :- the survey which are carried out for the determining of quantities or to
afford sufficient data for designing engineering works, such as roads, reservoirs, sewage
disposal, water supply , etc. are called engineering surveys.
2. military or defence survey :- the survey which are carried out for the preparation of map of
the area of military importance are called military surveys.
3. mine surveys :- the survey which are carried out for exploration of mineral wealth beneath
the surface of ground i.e. coal, copper, gold, iron, ores, etc. are called mine survey.
4. geological survey :- the survey which are carried out to ascertain the composition of earth
crust i.e. different states of rocks of the earth crust are called geological survey.
5. archeological survey:- the survey which are carried out to prepare the maps of ancient
culture i.e. antiquities , are called archeological survey.
#. Classification based on instrument used

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
1. chain survey :- chain surveying is a form of surveying that takes linear measurement in the
field. Suitable. In small area with clear details and a relatively flat area.
2. compass survey :- in compass surveying both the linear and angular measurements are taken
. horizontal angles are measured with a compass and linear measurement are taken with a tape
or a chain or laser range finder. Suitable for small level ground. And the area free from magnetic
influence.
3. plane table survey :- plane table surveying is one of the fastest method of surveying. Mostly
preferable in magnetic area where compass surveying is not possible also we can check errors
and mistake using check lines. It is a graphical method in which field observation and plotting
are done simultaneously.
4. theodolite survey :- theodolite is a surveying instrument that measures horizontal and
vertical angles. It is one of the precise methods of surveying. This type of surveying helps to find
the level difference, setting out, prolonging survey lines, etc. of the area .
5. tacheometric survey :- tacheometric surveying is angular in which horizontal and vertical
distance are calculated in which horizontal and vertical distance are calculated from angular
measurement. It is a convenient surveying method. Tacheometric surveying uses transit
theodolite with a stadia diaphragm for taking measurement. This method is preferable when a
direct method of surveying is not possible.
6. triangulation survey :- in triangulation surveying we trace series of triangles formed by
joining the survey points. The distance and relative points are calculated by trigonometric
relation between the length and angles of the triangle. It is preferable for hills and undulating
areas.
7. ariel and photographic survey :- it is a method of collecting geomatics or other images by
using airplanes, helicopter, UAVS, balloon or other areal methods.
Photographic surveying is the branch of surveying in which maps are prepared form photograph
taken form ground or air station.
#. Principle of survey (fundamental, principle, primary, basic)
1. working form whole to the part
- to minimize the accumulation of error,
- to localize the minor error within the frame of control points.
2. location of a point by measurement from two control point.
#. Secondary principles
3. consistency of work
4. independent check.
5. accuracy required.
#. Selection of suitable method
1. chain survey – small area having fairly level ground.
2. compass survey – where there is no effect of electric and magnetic field.
3. plane table survey – open ground
4. tacheometry survey – broken ground

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
#. Plan and maps
- Plan is defined as the graphical projection of the feature on or near the earth’s surface
on a horizontal plane on which horizontal distance and direction are shown.
- It is drawn on large scale – 1cm= 10m or <10m
- Plan is dimensional representation of place, region, structure, building with various
detail information.
- It gives detailed information about small areas in symbolic form.
- Small area
#. Map :- map is defined as a graphical projection of the feature on or near the earth’s surface
on a horizontal plane on which vertical distance are also represented by contour lines/hatch
with small scale.
- Small scale are used 1 cm=100m or >100m
- It is a topographical representation of any elements, region, place, etc.
- All the information are included.
- Large area.
#. Scales :- scale is defined as the fixed proportional where every distance between location of
the points on the map should be equal to their corresponding distance between their points on
the ground
- Selection of scale depends up on following factors.
1. Nature of the terrain and extent of territory
2. Purpose of surveying and size
3. Desirable precision
#. Representation of scale can be done as
1. numerical scales 2. Graphical scale
- engineer’s scale 1cm=1m - it’s length should be(18 to 32 cm)
1cm= 100m
- Fraction scale 1: 1000, 1: 100
#. Classification of scale
1. Plain scale :- it can measure up to two consecutive units.
e.g. meter and decimeter
feet and inches
2. Diagonal scale:- it can measure up to three consecutive units. e.g. meter, decimeter, and
centimeter.
3. Vernier scale.
- A vernier is a device for measuring accurately the fractional part of the smallest division
on the graduated scale.
- It consist of a little auxiliary scale which slide neat to of major scale.
- The difference between smallest division of main scale and vernier scale is called least
count.

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 - If S is the one division of primary scale and n is the number of divisions of vernier scale,
then (least count =S/n)
#. There are two types of vernier scale.
1. direct vernier
2. retrograde vernier
1. Direct vernier :-
- Main scale and vernier scale moves in same direction .
- N division of vernier scale equals to n-1 division of main scale.
- Smallest division of main scale (S) is greater than smallest division of vernier scale (v)
:- (least count = S-v)
And, nv = (n-1)S
V= (n-1)S/n
:- L.C. = S-(n-1)S/n
= nS – nS + S/n
= S/n
2. Retrograde vernier :-
- Main scale and vernier scale moves in opposite direction.
- N division of vernier scale equals to n+1 division of main scale.
- Smallest division of main scale (S) is less than smallest division of vernier scale (v).
:- least count = v-s
Nv= (n+1)s
V = (n+1)s/n
Now, L.C = (n+1)s -s
n
= ns+s-ns/n
= s/n
Q). If S is the value of one smallest division on main scale, v is the value of one smallest
division on the main scale and the scale is of direct vernier type, then least count is given by
a. s/n b. s/n-1 c. s+1/n d. s/n+1
Q). Least count is given by
a. p-v b. v-p c. p+v d. both (a) and (b)
4. Scale of chords :- a scale of chords is used to measure or to set off angles. It is marked either
on a rectangular protector or on an ordinary box wooden scale.
#. Entry into survey filed books and level books.
• Field book :- all observation and measurement taken during surveying are to be
recorded in a standard field book. It is an oblong book of size 200mmX 120mm. which
can be carried in the pocket.
#. Types
1. single line
2. double line

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 1. Single line:- the pages of a single book are having a red line along the length of the paper
in the middle of the width. It indicates the chain line. All chainage are written across it. The
space on either side of the is used for sketching the object and for noting offset distances.
2. Double distance :- there are two blue line with a space 15 to 20 mm in the middle of each
page. The space between the two lines is utilized for noting the chainage.
- in case of survey field book (chain survey) entry data is started from bottom page of field
book to top in upward direction while in case of the level book entry data is started from top
to bottom in downward direction
Note:- length of an arch of 12 km long lying on earth’s surface is only 1cm greater than the
subtended chord
18.2 km- 0.1 m 12
54.3 km- 0.3 m KM
91 km- 0.5 m
Q). in geodetic surveying sum of all the internal angles (degree) of a spherical triangle
should be
a. equal to 180
b. equal to 360
c. greater than 180
d. less than 180
#. Linear measurement :- there are two main methods of determining the distances
between points on the surface of the earth.
1. direct measurement:- distances are actually measured on the surface of the earth by
chains, tapes etc.
Some approximate method for reconnaissance.
1. Pacing
2. Passometer
3. Pedometer
4. Odometer
5. Speedometer
6. Measuring wheel
Note :- chaining is the most accurate method of making direct measurement.
2. competitive measurement:- in this method distances are determined by calculation as in
tacheometry and triangulation
#. Tape
1. cloth or linen tape:- it is made of closely wove linen and varnished to resist moisture.
- generally used for making offset measurement
2. metallic tape:- a linen tape reinforced with brass or copper wires to prevent stretches or
twisting of fiber is called metallic tape
- it is more accurate than cloth or linen tape
3. steel tape :- it is more accurate than metallic tape

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
4. invar tape :- (steel 64%& nickel 34%)
- invar tapes are mainly used for high degree of precision required for base measurement
- these are 6mm wide
Available in length of 30 m, 50m, and 100m
5. glass fiber tape
- these tapes do not stretch or shrink due to changes in temperature or moisture
- it can be used in any weather
- it is also known as synthetic tape.
#. Chain
1. engineers’ chain – length -100ft – divided into 100 links.
2. Gunter chain – length – 66ft - divided into 100 links.
3. metric chain – 20 m- divided into 100 links
4. metric chain – 30 m- divided into 150 links
5. revenue chain – 33ft – divided into 16 links
6. steel bands
- it is available in 20 m to 30m
- wide = 16mm
- it is used high accuracy is required
- metric chain is indicated by letter M
- links= 20cm
- ring= at each 1m
- Talley at each 5m,10m etc.
- links are made of galvanized mild steel 4 mm wire in dia.
- the handles have swivel joints to provide flexibility
- the handle of chain is made of brass and is included in whole length of the chain.
#. Ranging A line :- the process of marking a number of intermediate points on a survey line
joining two stations in the field so that the length between them may be measured correctly is
called ranging .
#. Classification of ranging
A. direct ranging
- when both the ends of line are intervisible.
- Minimum number of ranging rod required is 3.
B. indirect ranging
- when both ends are not intervisible
1. reciprocal ranging
- when the end stations of line are not intervisible due to interviewing raised ground but end
station are visible from intermediate points. e.g. hill rock.
- minimum 4 no. of ranging rod is required .
2. random ranging
- ranging a line across forest and wooded area

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
- end station are either visible form end nor from intermediate station
Leader Follower

1. to drag the chain forward 1. To direct the leader to be in line with

2. to insert an arrow at the end of every chain 2. to carry the rear end of the chain ensuring
. that it is dragged above the ground
3. to obey the instruction of the follower. 3. to pick up the arrow inserted by the
leader.
#. Ranging rod :- Dia- 3 cm length 2 to 3 m
#. Chaining along a sloping ground
1. direct method:- from top to bottom i.e. slopping downward. Stepping mthod.
2. indirect method :- by measuring along the slopes and angle of slope of the ground by
clinometer.

• Main survey station :- the point where two sides of main triangle meet is called a main
survey station. (A.B,C,D)
• Subsidiary survey station (or tie station):- the station which are selected on the main
survey lines for running auxiliary lines are called subsidiary stations. E & F.
• Main survey lines :- the chain line joining the two main survey station is known as main
survey line (AB,BC,CD,DA,AC)
• Auxiliary , subsidiary or tie lines :- the chain line joining subsidiary station with main
station is called subsidiary lines. (BF and FD)
- auxiliary lines are provided to locate the interior details which are far away from
the main lines.
• Base lines :- the longest of the main survey lines, is called a base line.
- various survey station are plotted with reference to the base line. (AC)
• Check lines :- the line which is run in the field to check the accuracy of the field work is
called check lines or proof line.
- If the measured length of a check line agrees with the length scaled off the plan,
the survey is accurate.
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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 - It is not required for plotting.
- Each triangle is generally provided with a check line.
- The check lines may be laid in such a way that maximum number of details are
intersected by it.
- Accuracy of measurement in plotting up to 0.25mm to that of measurement
0.25cm
#. Offset :- offset are the lateral measurement for locating the position of details.
1. perpendicular offset 2. Oblique offset
- 90 0 - any other angle than 900
- Short offset - long offset
Offset <15m offset>15m
Can be made perpendicular up to 15m by eye judgement
• Taking offset :- complete operation from taking measurements to making entry to field
book.
• Swing offset :- the fixing of perpendicular offset with help of chain/tape is known as
swing offset.
• Minimum number of offset :- 1 for circle
- 2 for line as well as polygonal irregular curved surface.
#. Right angle instrument
a. cross staff
i). open cross staff.
ii). French cross staff.
iii). Adjustable cross staff.
b. optical square :- it is used for setting out a line at 90 degree to another line.
- Works on the principle of double reflection.
c. prism square :-
- For making 90 degree
- Works on same principle as optical square.
- But no adjustment is required because angle between reflecting surfaces is
constant that is 450
#. Line ranger :- it is an instrument used for fixing the intermediate points on a chain line.
- It consists of two right angled isosceles triangle placed one above another.
• Plaster’s laths are also used for ranging , it is made of softwood, it’s length varies 0.5m to
1 m.
• Butt rods are used for measuring offset. It consist of two parts having one meter each
and are joined by hinge/rivets.
#. Chain surveying :-
- It is a branch of surveying in which only linear measurement are done and no angular
measurement are taken.
- It is the simplest and oldest type of surveying.
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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 Suitability Unsuitability
- Fairly level ground - Undulating ground
- Small areas - Large area
- Large scale plans required - Wooden countries
- Open area - Crowded area
#. Principles of chain surveying.
- The main principles of chain surveying is to divide the area into a number of triangles of
suitable sides. Since a triangle is the only simple can be plotted with the length of its
sides alone.

An ideal Triangle

#. Obstacles in chaining.
i). obstacles in ranging but not in chaining- hill rock.
ii). Obstacles in chaining but not in ranging- river and ponds.
iii). Obstacles in both ranging and chaining – tall buildings.
#. Details :- the term means a natural or manmade features at or near the ground surface.
It consist of the following.
a. hard details – hard details include building, roads, walls etc. (fix)
b. soft details :- soft details include river, vegetation, trees etc. (movable )
c. overhead details – it include power and telephone lines (above head)
d. underground details – it include survey of water mains, sewer etc. (below ground)
• Error = observed reading – correct (true) reading
• Correction = opposite of error
- If the chain is too long, the measured distance will be less and if the chain is too short,
the measured distance will be more.
- Source of error can be manual instrument or natural.
These all error can be classified as

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 A). Cumulative error :-the errors which occurs in the same direction and tend to accumulate
or to add up, are called cumulative errors. Such an error makes the apparent measurement
always either too long or short long.
#. Positive cumulative errors:- measured length >actual
It can be caused by following reasons
1. the length of the chain or tape is shortest than its standard length due to;
a. bending of links.
b. removal of too many rings form the chain during adjustment of its length.
c. knots in the connecting links.
d. the fields temperature being lower than that at which the tape was calibrated.
e. shrinkage of the tape when moist.
f. clogging of rings with mud.
2. the slope correction ignored while measuring along the slopping ground.
3. the sag correction if not applied when the chain or tape is suspended at its ends.
4. incorrect alignment.
5. bad ranging.
6. working in windy weather, when the tape belly’s out.
#. Negative cumulative errors :- the error which makes measured length less than the actual is
known as negative cumulative error.
- The length of the chain or tape is longer than its standard length.it can be due to
i). flattering of the connecting rings.
ii). Opening of the rings joints.
iii). The field temperature being higher than that at which the tape was calibrated.
• Cumulative errors are always proportional to the length of the line.
• Cumulative error, though large, can be corrected by applying the required correction.
B). Corresponding errors :- the errors which are liable to occur in either direction and tend to
compensate are called corresponding errors.
These are caused in following situations.
1. incorrect holding of the chain
2. the chain is not uniformly calibrated throughout its length.
3. refinement is not made in plumbing during stepping method.
4. chain angles are set out with a chain which is not uniformly adjusted
• Compensating errors are proportional to square root of the length of he chain.
• The nature of errors are not known, so corrections cannot be applied.
C). Accidental errors:- error occurring due to careless of the staffs involved in chaining. It is
proportional to square root of number of observation taken. α…………..
• Discrepancy :- it is the difference between two measured values of some quantity
• Residual error :- the difference between a measured quantity and the most probable
value it is also called variation.

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
 • The most probable error :- it is defined as that error for which there are equal chances
that the true value will be less than probable value or will be more than the probable
value.
• Angular error of closures should not exceed 15…….
• Permissible error :- the maximum allowable limit up to which a measurement may vary
is known as permissible error.
1. for measuring over rough or hilly ground the permissible error in chaining is 1 in 250
2. in an ordinary chain survey the maximum permissible error is 1 in 1000.
3. in steel tape or steel band chain the maximum permissible error is 1 in 2000.
4. in standardized steel and invar tape and correction for pull, sag , temperature, slope and
alignment is applied the maximum permissible error is 1 in 2500.
Note ;- L= true length of tape or chain
L’ = faulty length of tape or chain
1. true length of a line = (L’/L)2Xmeasured length of line.
2. true area of a plot = (L’/L)2 X measured of area of plot.
3. true volume of an excavation = (L’/L)3X measured volume
#. Correction for linear measurement
1. correction for standard length (Ca) = c/l x L
The sign of c and Ca will be same .
l = tape or chain length
L = measured length
2. correction for alignment
= l1 (1-cosα) + l2(1-cosα)
3. correction for slope = h2/2L(-ve)
4. correction for pull = (P-P0)L/AE
If p>p0correction is positive otherwise -ve
5. correction for temperature = (Tm-T0)xLxα
If Tm>T0 positive
T0>Tm negative
6. correction for sag = L/24(W/p)2
:- W = Lw
= L3w2/24P2 (-ve)
7. normal tension (p-p0)2/AE = L2W2/24p2 = L(W)2/24p2
:- p = 0.204W………
Q). Theory of probability is applied to
a. cumulative errors
b. compensative errors
c. accidental errors
d. none of the above

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
#. Accidental errors :- accidental errors are errors that occur due to the limitation of
measurement equipment or the observer. These errors are usually small and random and can
occur in either direction.
Some example ,
- Parallax errors
- Instrument errors
- Reading error tec.
Q). An offset scale always has the zero mark at its
a. middle
b. end
c. either middle or end
d. none of the above
Q). The maximum angular error in laying the direction is 30,if this maximum displacement of
the point on paper is same for both sources of errors the accuracy in the offset measurement
mill be
a. 1 in 18
b. 1 in 19
c. 1 in 25
d. 1 in 30
= sin300=1/19
Q). Which of the following instrument is generally used for base measurement ?
a. chain
b. metallic tape
c. steel tape
d. invar tape
Q). The base line is measured with
a. metallic tape
b. steel tape
c. invar tape
d. chain
Q). The accuracy of measurement in chain surveying does not depend on
a. leader
b. follower
c. length of chain
d. length of offset
Q). Prolongation of a chain line across an obstruction in chain surveying is done by
a. drawing perpendicular with a chain
b. by making angular observation
c. solution of triangle
d. all of the above methods.

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer
Q). The limiting length of an offset does not depend on ?
a. accuracy of the work
b. method of setting out perpendicular
c. scale of plotting
d. indefinite features to be surveyed .

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Surveying Full Notes – Civil Sub Engineer & Assistant Sub- engineer