MPSC CIVIL MAINS EXAM 10. Surveying

10. Surveying MPSC CIVIL ENGINEERING MAINS EXAM Page | 1

MPSC CIVIL MAINS EXAM

10. Surveying


CHAPTER 1 INTRODUCTION 12

CHAPTER 2 MEASUREMENT OF DISTANCES 23

CHAPTER 3 COMPASS SURVEYING 34

CHAPTER 4 LEVELLING AND CONTOURING 48

CHAPTER 5 THEODOLITE AND THEODOLITE TRAVERSE 64

CHAPTER 6 PLANE TABLE SURVEYING 78

CHAPTER 7 TACHEOMETRY 85

CHAPTER 8 CURVES 94

CHAPTER 9 COMPUTATION OF AREA & VOLUME 107

CHAPTER 10 HYDROGRAPHIC SURVEYING 113

CHAPTER 11 PHOTOGRAMMETRY 125


CHAPTER 1 INTRODUCTION 12

1.1 Introduction to Surveying 12 1.2 Primary classification of surveying 12 1.3 Functional classification 13 1.4 Classifications based on instrument used 14 1.5 Principal of Surveying 16 1.6 Difference between Plan and map 17 1.7 SCALE OF A MAP 17 1.8 Errors Due To Shrinkage of a Map 18 1.9 ERRORS DUE TO WRONG MEASURING SCALE 18 1.10 Types of Measuring Scales 18 1.11 Use of Vernier’s in scales 19 Questions with explanation 19 Answers and Explanation 20 Question for practice 21

CHAPTER 2 MEASUREMENT OF DISTANCES 23

2.1 Introduction to Measurement of Distances 23 2.2 Methods of Linear Measurement 23 2.3 Chain Surveying 23 2.4 Tapes: 24 2.5 Miscellaneous equipment for chaining 24 2.6 Ranging 25 2.7 Errors in Chaining 25 2.8 Chain Corrections 26 Tape corrections 26 2.9 Reduction of length to mean sea level 27 2.10 Hypotenusal Allowance 28 2.11 Degree of Accuracy 28 2.12 Principal of chain surveying 28 2.13 Survey lines 29 2.14 Offsets 29 2.15 Instruments setting out right angles 30 2.16 Obstacles in chaining 30


Questions with Explanation 30 Question for practice 31

CHAPTER 3 COMPASS SURVEYING 34

3.1 Introduction to Compass Surveying 34 3.2 TYPES OF TRAVERSE 34 3.3 Types of Meridians 35 3.4 Types of Bearings:- 35 3.5 System of bearing 35 3.6 Fore bearing and Back Bearing 36 3.7 Calculation of Angles from Bearings 36 3.8 Calculation of Bearings from Angles 38 3.9 Prismatic Compass 38 3.10 Parts of prismatic compass 39 3.11 Dip 39 3.12 Local attraction 40 3.13 MAGNETIC DECLINATION 40 3.15 Comparison of A Prismatic Compass With A Surveyor's Compass 42 3.16 Adjustment of Prismatic compass 43 3.17 ERRORS AND MEASUREMENTS: 43 3.18 Definitions 43 3.19 Probable Errors:- 44 Questions with Explanation 44 Question for practice 46

CHAPTER 4 LEVELLING AND CONTOURING 48

4.1 Introduction to Levelling and Contouring 48 4.2 Applications of levelling 48 4.3 Definitions 48 4.4 Types of Bench Marks 49 4.5 Different Methods of Levelling 49 4.6 Classification of Direct Levelling Methods 50 4.7 Terms Used in Levelling 51 4.8 Commonly used leveling instruments 52 4.9 Methods of Finding the Reduced Levels (R.L.) 53


4.10 Curvature and Refraction Corrections:- 53 4.11 Sensitivity of a Level Tube 54 4.12 Omitted Measurements 55 4.13 Contouring 57 Scale of the Map. 58 Characteristics of Contours 58 Methods of Locating Contours 60 Uses of contour maps 60 Questions with Explanation 61 Question for practice 62

CHAPTER 5 THEODOLITE AND THEODOLITE TRAVERSE 64

5.1 Introduction to Theodolite 64 5.2 Parts of a transit Theodolite: 64 5.3 Important Terms in Theodolite Surveying 65 5.4 Temporary adjustments of Theodolite: 66 5.5 Permanent adjustments of Theodolite: 66 5.6 Fundamental lines and their relations: 67 5.7 Measurement of horizontal angles: 67 5.8 Measurement of vertical angles: 68 5.8 Introduction to Theodolite Traverse 68 5.9 Linear Measurements 68 5.10 Angular Measurements 68 5.11 LATITUDES AND DEPARTURES 69 5.12 Consecutive and Independent Coordinates: 69 5.13 Checks in a Closed Traverse 70 5.14 Error of Closure 71 5.15 Various checks applied to the traverse survey: 71 5.16 Balancing methods 72 5.17 Omitted Measurements:- 73 Questions with Explanation 73 Question for practice 74

CHAPTER 6 PLANE TABLE SURVEYING 78

6.1 Introduction to Plane Table Surveying 78


6.2 Principle of Plane Table Surveying. 79 6.3 Accessories of Plane table surveying: 79 6.4 Basic Terms 80 6.5 Methods of Orientation 80 6.6 Methods of Plane Table Surveying: 80 Questions with Explanation 81 Answer and explanation 82 Question for practice 83

CHAPTER 7 TACHEOMETRY 85

7.1 Introduction to Tacheometry 85 7.2 Advantages of Tacheometric Surveying 85 7.3 Tacheometer 85 7.4 Characteristics of a Tacheometer 86 7.5 Systems of Tacheometric Measurements: 86 7.5 Principle of Stadia Method of Tacheometry 87 7.6 Tacheometric Measurement with inclined Line of Sight and Staff Vertical 88 7.7 Inclined Line of Sight with Staff Normal to the Line of Sight 89 7.8 Advantages of Holding the Staff Vertical 90 7.9 Advantages of Holding the Staff Normal to The Line of Sight 90 7.10 Tangential Method of Tacheometry 90 Questions For Practice 91

CHAPTER 8 CURVES 94

8.1 Introduction to Curves 94 8.2 Classification of Curves 94 8.3 Horizontal Curves 94 8.4 Vertical Curves 96 8.5 Simple Circular Curve-A Detailed Overview 97 8.6 Need for Transition Curve 101 8.7 Comparison of Transition Curves 103 Questions with Explanation 104 Question for practice 105


CHAPTER 9 COMPUTATION OF AREA & VOLUME 107

9.1 Introduction to Computation of Area and Volume 107 9.2 AREA 107 9.3 TRIANGLE METHOD 107 9.4 AREA OF A SEGMENT 107 9.5 AREA OF A TRACT WITH STRAIGHT IRREGULAR BOUNDARIES 108 9.6 Other methods for measurement of Area 109 9.7 COMPUTATION OF VOLUMES 109 9.8 VOLUME BY MEAN-AREA METHOD 109 9.9 TRAPEZOIDAL RULE 110 9.10 Prismoid Formula 110 9.11 Prismoidal correction: 110 9.12 Curvature correction 110

CHAPTER 10 HYDROGRAPHIC SURVEYING 113

10.1 Introduction to Hydrographic Surveying 113 10.2 Applications of Hydrographic Surveying 113 10.3 Uses of Hydrographic Surveying 114 10.4 Preliminary Steps in Hydrographic Surveying 114 10.5 Sounding in Hydrographic Survey 115 10.6 Equipment for Sounding: 115 10.7 Locating the Soundings 117 10.8 Reduction of Soundings 122

CHAPTER 11 PHOTOGRAMMETRY 125

11.1 Introduction to Photogrammetry 125 11.2 Terrestrial Photograph and Terrestrial Photogrammetry 125 11.3 Aerial Photograph and Aerial Photogrammetry. 125 11.4 Advantages of Aerial Surveying 126 11.5 Aerial Photograph 126 11.6 Terminologies in Aerial Surveying: 126 11.7 Relief Displacement 128 11.8 Area Covered by One Photograph 128 11.9 Exposure Interval 129 11.10 Air Base 129


11.11 Classification of Photographs 129 11.12 Information recorded on photographs 130 11.13 Introductory definitions for photographs: 131 Questions with explanation 132 Answers and explanation 133



1 Introduction of Surveying

CHAPTER 1 INTRODUCTION

1.1 Introduction to Surveying

Surveying is the science and art of determining the relative positions of various points above, on or below the surface of the earth.

The relative positions are determined by meas-uring horizontal distances, vertical distances (elevations), horizontal angles and vertical an-gles accurately using various surveying instru-ments.

After taking the measurements in the field, computations are done and the plans and maps are prepared in the office.

These plans and maps are used for planning of engineering works, marking of boundaries, computations of areas and volumes, and vari-ous other purposes.

Surveying also includes the art of setting out or locating the points on the ground from the plan or map.

The points and lines have to be located on the ground before starting the construction of engi-neering work, such as buildings, roads, bridges, and dams

1.2 Primary classification of surveying

The Primary division of surveying is made on the basis whether the curvature of the earth is considered or whether the earth is assumed to be a flat plane.

The actual shape of the earth is an oblate sphe-roid The length of the pole axis, is about 12713.168 km and that of the equatorial axis is about 12756.602 km,

Thus the polar axis is shorter than the equato-rial axis by about 43.434 km

On the basis of whether the curvature of the earth is taken into account or not ,surveying can be divided into two main categories

Plane surveying

Plane surveying is the type of surveying where the mean surface of the earth is considered as a plane. All angles are considered to be plane angles.

For small areas less than 250 km2 plane survey-ing can safely be used. For most engineering projects such as a canal, railway, highway, building, pipeline etc. constructions, this type of surveying is used.

It is worth noting that the difference between an arc distance of 18.5 km and the subtended chord lying in the earth's surface.

Also the sum of the angles of a plane triangle and the sum of the angles in a spherical triangle differ by 1 second for a triangle on the earth's surface having an area of 196 km2

Geodetic surveying

It is the type of surveying in which the curvature of the earth is taken into consideration, and a very high standard of accuracy is maintained.

The main object of geodetic surveying is to de-termine the precise location of a system of widely spaced points on the surface of the earth.


The points so located are used as control sta-tion of the primary surveys. The secondary sur-veys of less precision are connected to these control stations.

For large area more than 250km2, geodetic sur-veying is used

1.3 Functional classification

[MES PRE 2012, MES PRE 2013]

1. Control Surveying. It consists of establishing the horizontal and

vertical positions of widely spaced control points using the principles of geodetic survey-ing.

In India, control surveying is done by the Survey of India

2. Land Surveying: Land surveys are conducted to determine the

boundaries and areas of tracts of land. These also known as property surveys 3. City Surveys. These surveys are conducted within the limits

of a city for urban planning. These are required for the purpose of layout of

streets, buildings, sewers, pipes, etc 4. Topographical Surveys: - These surveys are required to establish hori-

zontal locations of the various points as well as their vertical locations, to show the natural fea-tures of the country.

5. Route Surveying. These surveys are special types of topograph-

ical surveys conducted along a proposed route for a highway, railway, sewer line, etc. The route survey is done along a wide strip.

6. Mine Surveys. These surveys are conducted to determine the

relative positions and elevations of mines, shafts, adits, bore holes, etc. for underground works.

7. Hydrographic Surveys.

These surveys are conducted on or near the body of water, such as lakes, rivers, bays, har-bours, Marine surveys are the special type of hy-drographic survey.

The hydrographic surveys consists of locating shorelines, estimation of water flow, and deter-mination of the shape of areas beneath the wa-ter surface.

It also includes the determination of channel depth, location of locks, sand bars, buoys, etc:

8. Engineering Surveys. Engineering surveys are conducted to collect

data for the designing and planning of engineer-ing works

such as building, roads, bridges, dams, reser-voirs, sewers, and water supply lines These sur-veys generally include land surveys, city sur-veys, topographical surveys and route surveys discussed above.

9. Astronomic Surveys. These surveys are conducted for the determina-

tion of latitudes, longitudes, azimuths, local time, etc. for various places on the earth by ob-serving heavenly bodies (the sun or stars).

The absolute locations of various points on the earth are obtained by astronomic surveys

10. Satellite Surveys. These surveys are conducted to obtain inter-

continental, inter datum and interisland geo-detic ties all the world over by artificial earth satellites.

These surveys are done by space agencies 11. Geological Surveys. Geological surveys are conducted to obtain in-

formation about different strata of earth's sur-face for geological studies.

Geological maps are prepared to depict the de-tails of the strata

12. Construction Surveys. All the above-mentioned surveys are conducted

to obtain information required for preparation of maps, plans, sections, etc.


After the plans have been prepared and the structures designed, the construction surveys is conducted.

The points and lines are established on the ground, and the layout plan of the structure is marked on the ground.

Stakes are driven for setting out. Thus con-struction surveys are the reverse of engineering surveys

13. Miscellaneous Surveys a) Archaeological surveys. These are done to

unearth relics of antiquity.

b) Military surveys. These are conducted to de-termine the routes and points of strategic im-portance.

c) Gravity surveys. These are conducted to measure the intensity of the gravitational force at various points

d) General surveys. These are used to acquire and accumulate qualitative information and quantitative data for a specific purpose by observing, counting, classifying and record-ing according to the need. For example, soil survey and traffic survey.

1.4 Classifications based on instrument used

1. Chain survey 2. Theodolite survey 3. Transverse survey 4. Triangulation survey

5. Tacheometric survey 6. Plane table survey 7. Photographic survey 8. Aerial survey

Classification of Survey Based on Instrument Used

a) Chain Survey:

Here, only the linear measurements are made with a chain (or a tape) and no angular meas-urements are made.

This survey is of limited use, since it requires clear ground without any obstruction like inter-vening trees, buildings, rivers etc.

This survey is particularly useful for laying of sewer lines, water supply lines, construction of roads etc.

(b) Traverse Survey:

Here, both the linear and angular measure-ments are made, the former being made with a tape or a chain and the later with a compass.

This survey is useful for large projects like dams and reservoirs.

(c) Leveling:

Here, elevations of different points are deter-mined.

A graduated staff and a level are used for this purpose. Almost all projects require determina-tion of the elevation of the different points and this is achieved by leveling.

(d) Tacheometry:

Here, in this type of survey, both the horizontal distance and the vertical distance are meas-ured by sighting a graduated staff with a transit telescope fitted with an anallatic lens.

It is particularly useful when direct measure-ment of horizontal distances are not possible.

(e) Plane Tabling:

In this, observations and plotting are done sim-ultaneously in the field.

Previous Year Questions MES PRE 2013

1. A compound curve of Sun or any fixed star is __________. A. Celestial Survey B. Astrological Survey C. Heaven Survey D. Astronomical Survey

MES PRE 2012

2. The survey which consist of observation of the heavenly bod-ies such as sun or any fixed star is ________ A. Celestial Survey B. Astrological Survey C. Heaven Survey D. Astronomical Survey


The advantage of this method is that there is least possibility of omitting any important measurement since the actual field being sur-veyed is in view on the plot in the field itself.

The drawbacks of this method are that it cannot be done in humid or rainy weather and the car-rying of plane table apparatus is cumbersome.

(f) Triangulation:

This method of survey is used for large areas. The entire area is divided into a network of tri-angles and any one side of any of the triangles so formed is measured very precisely.

This line is referred to as baseline. All the an-gles of the network are measured.

The lengths of the sides of the triangles are then computed using the laws of triangles.

(g) EDM Survey:

EDM refers to Electronic Distance Measure-ment and in this method of survey, distances are measured electronically using wave propa-gation, reflection and subsequent reception of the reflected wave.

Some of the examples of EDM instruments are tellurometer, distomat, geodimeter etc.

(h) Total Station Survey:

Total station is the combination of conven-tional transit theodolite with EDM instrument.

It reads and records the horizontal and vertical distances together with slope distances.

This instrument also computes the Cartesian coordinates of the observed points, slope cor-rections, elevation of remote objects etc.

Survey carried out using total station is referred to as total station survey.

(I) Satellite Survey:

In this method of survey, information about the land or space is determined using satellite based navigation system like the GPS (Global Positioning System).

Another method is the Remote Sensing wherein the data about an object is acquired using the sensors placed on satellite.

Classification of Survey based on Purpose

(a) Geological Survey:

In this type of survey, information about both the surface and sub-surface is acquired for as-sessing the extent of different reserves like the minerals, rocks etc.

It is also used for locating the faults, folds and other unconformities in the ground.

This survey helps in determining the type of foundation, soil treatment required etc.

(b) Geographical Survey:

This survey is done for preparation of geo-graphical maps depicting the land use effi-ciency, irrigation intensity, surface drainage, slope profile, contours etc.

(c) Engineering Survey:

This survey is required to be done for acquiring information for the planning and design of engi-neering projects like the highways, dams, rail-way line, water supply design, reservoirs, bridges etc.

It involves topographic survey of the area, earthwork measurement etc.

(d) Cadastral Survey:

These are done to establish boundary of prop-erties for legal purposes.

These are also called public land survey.

(e) Defense Survey:

Such surveys are done for military purpose. They provide strategic information for deciding the future course of action.

Aerial and topographical maps of the area are prepared which gives crucial information about the existing roads, airports, ordnance depots etc.

(f) Mine Survey:


This requires both the surface and the under-ground surveys.

It involves making the surface map and doing the underground survey for locating the reverse of minerals.

(g) Route Survey:

It is a sort of linear survey for deciding the align-ment of a highway or a railway.

(h) Archaeological Survey:

This is done to gather information about the an-cient monuments, towns, villages, kingdoms, past civilizations, temples, forts etc. buried un-derground due to natural forces like earth-quakes, landslides, incandescent floods etc.

It gives an idea about the past history, culture etc. of the civilization that existed in the past.

1.5 Principal of Surveying

The various methods of surveying are based on following two main principles

1. To work from whole to part. This principle states that it is essential to first

establish control points with high precision and then establish minor control points.

Any inner details can further be located within the minor control points.

Control Point

Boundary of the area of town

A

B

C

D

p

q

r

Control Point

E

Fig 1.1 To work from whole to the part means that en-

tire area or a very large area from the area to be

surveyed is first considered and then its smaller parts are considered

Working by procedure enables to prevent accu-mulation of possible errors in the surveying work of large area.

The principle to work from whole to the part can be well understood by the following example.

Consider a very large area like a town to be sur-veyed as shown in Fig.1.1

First of all, control points A, B, C, D and E are fixed or located with great care within the boundary of the area of town as shown in Fig. 1.1

The area which is obtained from these control points is divided into the number of triangles which are further sub-divided into small trian-gles by the method of triangulation; e.g. Trian-gle CED is further divided into small triangle 'PQR' as shown in Fig. 1.

The details within these triangles are surveyed with less accuracy. This is known as working from whole to the part.

By this principle or system, accumulation of possible errors in the surveying work can be prevented

It is noted that if we start from the small areas and then cover large area then mistakes and er-rors may go accumulating and finally affects the surveying work resulting in less accuracy

City survey or town survey or topographical sur-vey can more precisely be carried out by this principle

2. To fix or to locate a new point or station by at least two independent measurements or pro-cesses

In surveying, the relative positions of points are located by measurements from at least two points of reference whose positions are known.

In short, the position of new points from the two known points can be fixed or located by taking

;R


(a) linear measurements (b) angular measure-ments or (c) both linear and angular measure-ments.

In this method, two points are selected in the field and the distance between them is meas-ured.

α

(a) (b) (c)

90o

P P P

Q Q Q

R

R R

(d)

P

Q

R

(e)

P

Q

R

ββ

α

Fig. 1.2

Then relative positions of the other points in the field can be located from these two reference points

1.6 Difference between Plan and map

Plan :- A plan graphically represents the fea-tures on or near the earth's surface as projected on a horizontal plane

Map:-. If the scale of the graphical projection on a horizontal plane is small, the plan is termed map, addition, a map generally shows some ad-ditional features, such as reliefs, hachures and contour lines to indicate undulations on the ground

1.7 SCALE OF A MAP

MES PRE 2011, 2013, 2015, MES MAINS 2019

Scale of a map is the ratio of the distance marked on the map to the corresponding dis-tance on the ground.

As the areas involved are rather large, it is es-sential to select a suitable scale for represent-ing the area on a map. Selection of the scale de-pends on the purpose, size and the required pre-cision of plotting.

Scales are generally classified as large, medium and small as under

Large scale: 1 cm = 10 m or less than 10 m

Medium scale: 1 cm = 10 m to 100 m Small scale: 1 cm = 100 m or more than 100m

Representation of Scale

Following three methods represent the scale

1. Engineer's scale:- It is indicated by a statement. For example, 1

cm = 50 m. According to this scale, a specified distance-on

the map represents the corresponding distance on the ground.

In this example, 1 cm on the map represents 50 m on the ground

2. Representative Fraction (R.F.):- It is indicated by a ratio. The representative fraction is the ratio of the

distance on the map to the corresponding dis-tance on the ground. For example, for a scale of 1 cm = 50 m, 1 cm on the map represents 50 m (5000 cm) on the ground.

Therefore, the representative fraction (R.F.) is 1/5000 or 1 : 5000

3. Graphical scale: -

A graphical scale is a line drawn on the map so that its map distance corresponds to a conven-ient unit of length on the ground.

A graphical scale is constructed on the map by drawing a line and marking the ground dis-tances directly on it.

Suggested scale for different type of surveys.

S.r. Purpose of Survey Scale R.F.

1. Building site 1 cm= 10 m 1 : 1000


2. Town planning, reser-voir planning, etc.

1 cm = 100 m 1 : 10,000

3. Route surveys 1 cm = 100 m 1 : 10,000

4. Longitudinal sections

a. Horizontal scale

b. Vertical scale

1 cm = 10 m

1 cm = lm

1 : 1000

1 : 100

5. Cross-sections 1 cm= lm 1 : 100

6. Land surveys 1 cm = 5 m - 50 m

1 : 500 to 1: 5000

7. Topographical maps 1 cm = 0.25 km to 2.5 km

1 : 25,000 to

1 : 250,000

8. Geographical maps 1 cm = 5 km to 150 km

1 : 5,00,000 to

1 : 150,00,000

1.8 Errors Due To Shrinkage of a Map

The drawing paper generally shrinks due to var-iation in the atmospheric temperature, humid-ity, etc. Consequently; all the lines marked on the map shrink to some extent.

Thus the lengths measured from the map after shrinkage of a map are not the correct dis-tances.

If a graphical scale had also been drawn on the map, the correct distances can be measured us-ing that scale. In absence of a graphical scale, the correct distance can be determined as un-der

The ratio of the shrunk length to the actual length is known as the shrinkage ratio or the shrinkage factor. It is always less than unity. Thus the shrunk scale is less than the original scale Shrunk scale = Original scale x shrinkage Factor

The scales should be expressed as a ratio

Alternatively,

Shrunk R.F. = Original R.F. x Shrinkage Factor Thus

Correct Distance = Measured area

Shrinkage factor

As the area is product of two distances (length and width), with the dimensions [L2],

Correct Area = Measured area

(Shrinkage factor)2

1.9 ERRORS DUE TO WRONG MEASURING SCALE

If a wrong measuring scale is used to measure the length of a line already drawn on the plan, the measured length will not be correct.

For example, if the plan has been drawn to a scale of 1: 200, and the length is measured with a scale of R.F. of 1: 250, the measured distance of 25 cm will be actually 20 cm on the plan.

Thus

Correct

Distance= (

RF of wrong scale

RF of correct scale) ×

measuredlength

As the area product of two distances

Correct

Distance= (

RF of wrong scale

RF of correct scale)

2

×measured

length

1.10 Types of Measuring Scales

1. Plain scale :- It is possible to measure two suc-cessive dimensions only e.g. metres and deci-meters

Previous Year Questions MES PRE 2011

3. The representation fraction of a map scale 1cm = 5 km is ___________. A. 1/500000 B. 1/500 C. 1/5000 D. 1/50000

MES PRE 2013

4. The representative fraction (R. F) of scale 1 cm = 500 m is A. 1:500 B. 1:5000 C. 1:50000 D. 1:50

MES MAINS 2019

5. A rectangular plot of land of area 0.45 hectare is repre-sented on a map by a similar rectangle of area 5 cm2. Cal-culate R.F. of the scale of the map. Draw a scale to read upto a single metre from the map. A. 1:5000 B. 1:8000 C. 1:9000 D. 1:3000

MES PRE 2015

6. Map is a graphical representation of the features on small scale as projected on a A. Horizontal plane B. Horizontal line C. Plane parallel to feature D. In any plane

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MPSC CIVIL MAINS EXAM 10. Surveying