II/IV B.Tech (Regular/Supply) Degree Examination (April-2017)

II SEM

SURVEYING - II (14CE403)

(CIVIL ENGINEERING)

Scheme of Evaluation

Prepared by Head of the Department

Y. Ravi Dr. Ch. Naga Satish Kumar

Assistant Professor,

Department of Civil Engineering,

Bapatla Engineering College.

Cell No: 9849165681 & 8500614162

Head of the Department Subject Coordinator

Dr. Ch. Naga Satish Kumar Y. Ravi

II/IV B.Tech (Regular/supply) Degree Examination (April-2017)

Second Sem Surveying- II (14CE403) Civil Engineering

(Scheme of Evaluation)

1. Answer all questions (12 x 1 = 12M)

a. Define Elevation – Capacity Curve.

Ans: The plot between the capacity or volume or storage (along x-axis) and elevation

(along y-axis) of reservoir is known as Elevation – Capacity Curve.

b. Define Satellite station.

Ans: Sometimes it becomes difficult or impossible to set up the theodolite at a

triangular station in such cases a subsidary station is selected near the main station as

instrument station. Observations are taken from the subsidary station. This subsidary

station is known as the satellite station or false station or eccentric station.

c. Define trigonometric leveling and it types.

Ans: Trignometric levelling is an indirect method of levelling in which the relative

elevations of various points are determined from the vertical angles measured with a

theodolite and the horizontal distances are measured with a tape.

Types

Plane Trignometric levelling earth curvature is neglected

Geodetic Trignometric levelling earth curvature is considered.

d. Explain Axis- signal correction.

Ans: If the height of target or signal above the ground is not equal to that of the

instrument axis, the measured angles are to be corrected by applying a correction called

the axis-signal correction or eye-object correction.

e. What is ver sine of simple curve?

Ans: It also known as mid-ordinate of the curve.

It is define as the ordinate from the mid-point of the long chord to the mid-point of the

curve.

f. Define refraction and curvature.

Ans: The effect of refraction is to make the object appear higher than what it really is.

The effect is to decrease the staff readings.

The effect of refraction is to make the object appear lower than they actually are.

The effect is to increase the staff readings.

g. Differentiate between trilateration and triangulation.

Ans: There is not much difference between trilateration & Triangulation

Trilateration, method of surveying in which the lengths of the sides of a triangle are

measured, usually by electronic means, and, from this information, angles are

computed.

Triangulation is the surveying technique in which unknown distances between stations

are determined using the trigonometric relations of a triangle.

h. Define horizontal and vertical control.

Ans: The horizontal control consists of establishing reference marks of known plan positions

from which horizontal distances are measured for setting out.

The vertical control consists of establishing the reference marks of known elevation relative to

some datum. The levels of the various points on the structure are measured from the vertical

control points.

i. What are the various methods of curve settings?

Ans: Tape methods, Tape and Theodolite methods, Two Theodolite method,

Tachometric method, Total-station instrument method.

j. Define GCP.

Ans: Ground Control Points are defined as points on the surface of the earth of a

known location used to geo-reference data.

k. Compare stadia and tangential method?

Ans: In stadia method, diaphragm in tacheometer is provided with

three stadia hairs (upper, middle and lower) and stadia hair reading is taken by

looking through telescope.

The tangential method of tacheometry is being used when stadia hairs are not

present in the diaphragm of the instrument or when the staff is too far to read. In this

method, the staff sighted is fitted with two big targets (or vanes) spaced at a fixed

vertical distances.

l. What is the principle of EDM?

Ans: Law of optics.

UNIT -I

2. (a) Explain the theory and working of a planimeter. (6M)

For explaining the theory (4M)

For explaining the working (2M)

Theory of Planimeter For figure 1M

The above shows the schematic diagram (plan view) of a polar planimeter.

Working of Planimeter (2M) The planimeter rests on three points – the wheel, the anchor point and the tracing point.

Out of these three, the anchor point remains fixed in position while the wheel partly rolls

and partly slides as the tracing point is moved along the boundary.

Since the plane of the wheel is perpendicular to the plane of the centre line of the tracing

arm, the wheel measures only normal displacement – when it actually rolls.

To find the area of the plan, the anchor point is either placed outside the area (if the area is

small) or it is placed inside the area (if the area is large)

- A point is then marked on the boundary of area and the tracing point kept exactly over it.

The initial reading of the wheel is then taken.

The tracing point is now moved clock-wise along the boundary till it comes to the starting

point.

The final reading of the drum is taken.

The area of the figure is then calculated from the following formula:

Area (A) = M (F.R – I.R ± 10 N + C)

F.R = final reading; I.R = Initial reading

N = Number of complete revolutions of the disc. It is equal to the number of times the zero

mark of the dial passes the fixed index mark.

**Use plus sign if the zero mark of the dial passes the index mark in a clockwise direction

and minus sign when it passes in the anti-clockwise direction.

M = a multiplying constant, also sometimes known as the planimeter constant. It is equal to

the area per revolution of the roller.

C = constant of the instrument which when multiplied by M, gives the area of zero circle.

The constant C is to be added only when the anchor point is inside the area.

2. (b) A road embankment is 9 m wide at the formation level. The centre line of the

embankment is 2.75 m above the ground surface. If the ground slope is 1 in 22 at right

angles to the centre line, and the side slopes are 1.5: 1, calculate the side widths and the

area of cross section by various formulae. (6M)

Sol:

(OR)

3. (a) Draw a neat sketch of a two level section, and derive an expression for the area of

cross-section. (7M)

For Sketches with correct notations (2M)

For derivation (5M)

Sol:

3. (b) Calculate the area of a plan from the following readings of a planimeter,

I.R = 8.128 and F.R = 1.435

The zero of the disc passed the fixed index mark twice in the clockwise direction. The

anchor point was placed outside the plan, and the tracing point was moved in the

clockwise direction. Take M =100 cm2 , C= 19.5. (5M)

Sol:

UNIT -II

4. (a) Write the procedure to determine the height of the object when base is

inaccessible by trigonometric method using theodolite. (When the instruments are at

the same level) (6M)

For Fig (1M)

For procedure (2M)

For derivation (3M)

4. (b) Trignometric leveling was carried out to determine the difference in elevation of

two stations P and Q 1500 m apart. If the angle of elevation at P was 2 45 and the angle

of depression at Q was 2 35, find the height of Q above P, and refraction correction.

The height of instrument above its station was 1.1 m and that of signal was 4.4 m. (6M)

Sol:

(OR)

5. (a) Derive expression for the horizontal distance D and the vertical intercept V when

the staff is normal. (6M)

For Fig (2M)

For derivation of Angle of elevation (3M)

For derivation of Angle of elevation (1M)

Angle of Depression:

5. (b) In tacheometry surveying the readings of 3 diaphragm webs on a staff held at a distant

point were recorded as 0.650,0.990 and 1.320 m, the telescope held horizontally. If the

multiplying and additive constants were 100 and 0.5 respectively, calculate the distance of the

staff from the instrument station. If the R.L of the instrument station was 11.530 m and

height of sight was 1.15 m, determine the R.L of staff station. (6M)

Sol:

UNIT -III

6. (a) Explain the procedure for setting out a small sewer. (6M)

For Figure (2M)

For Procedure (4M)

A sewer is a large diameter pipe in which sewage flows as open channel flow or gravity flow.

The sewer, therefore, does not run full. The setting out of a sewer consists of fixing the grade stakes and

sight rails at the required slope. The persons digging the sewer trench can find out the required depth of

cutting a' various points along the trench from the grade stakes. The persons laying the sewer can find out

the exact elevation of the sewer invert from the site rail.

Procedure:

1. Set grade stakes at a suitable interval, say 15 in, parallel to the line of sewer. The grade

stakes are set off the sewer so that these would not be disturbed during excavation.

On hard surfaces where stakes cannot be driven, use paint to mark the grade stake point.

Alternatively, use spikes, nails, etc.

Mark the chainage, the offset distance and the depth of cutting on each grade stake.

2. Set a sight rail across the trench at each grade stake point.

A sight rail consists of a cross-piece of a horizontal wooden board nailed to a pair of uprights

(posts) driven into the ground. The horizontal board is fixed at a convenient height so that a person can

conveniently align his eyes with the upper face.

Each sight rail should be set at a selected height h above the invert level of the sewer at that point.

In other words, the R.L. of the upper face of the sight rail is equal to the R.L. of the invert level of the

sewer at that point plus the height h. The height h is kept equal to the length of the boning rod.

3. Mark the alignment of the sewer line on the sight rail with a theodolite-The theodolite can be set

up on a platform across the trench.

Drive a nail into the top face of each sight rail at the exact location along the line of sight of the

theodolite directed along the sewer alignment.

4. Stretch a siring between the nails on the adjacent sight rails to determine the exact location of the

sewer in the trench.

The person laying the sewer would measure the required depth (h) from the string line to locate the

invert level of the sewer. Generally, a boning rod is used for this purpose.

A boning rod consists of a wooden pole having horizontal boards at its top to form a T-shaped rod of

specified length (h). While determining the location of the invert level of the sewer, the cross-head of the

boning rod is kept at the string level. The toe of the boning rod then gives the required invert level.

For illustration, let us assume that two grade stakes A and B at a distance of 30 m along the sewer line

have R.L. of 100.00 and 100.12, respectively. If the invert level of the sewer at A is 98.00, and the length of the

boning rod is 3.50 m, the R.L. of the top of the rail at A would be 98.00 + 3.50 = 101.50. The height of the sight

rail above the grade stake A would be 101.50 -100.00 = 1. 50 m.

If the proposed slope of the sewer is 1 in 100, the invert level at B would be 98.00 – 30/100 =

97.'70. The required R.L. of the top of the sight rail at B would be 97.70 + 3.50 = 101.20. The required height

of the sight rail above the grade stake would be 101.20 – 100.12 = 1 '08 m.

6. (b) Write short notes on (6M)

i) Boning rod ii) Batter board iii) Reference pillars iv) Slope rail

For Explaining each one in one or two sentences (1.5 M) (4x1.5 =6M)

Ans:

Boning rod:

A boning rod consists of a wooden pole having horizontal boards at its top to form a T-shaped rod of

specified length (h). While determining the location of the invert level of the sewer, the cross-head of the

boning rod is kept at the string level. The toe of the boning rod then gives the required invert level.

Batter board:

Batter boards, also called profile boards, are used for accurate layout of the foundation. A batter board

consists of a horizontal board fixed to the top of vertical posts. The batter board used in the foundation layout

consists of three posts forming a right angle in the plan. The posts, which are long stakes, are driven at each

corner of the building as offset pegs. Horizontal boards are then nailed to the top of the posts at the

desired elevation.

Reference pillars:

For large, important works, reference pillars of masonry or concrete arc constructed near each corner

point. These pillars are usually 20 to 30 cm thick and about 15 cm wider than the width of the foundation

trench. The top of the pillars is set at some fixed level, usually the plinth level. Nail! or bolts are embedded in

the top of these pillars to indicate the centre line an outer lines of the foundation trench. Sometimes, bolts

indicating the plinth lines on the plan are also embedded.

Slope rail:

These are used for controlling the side slopes in embankment and in cuttings. These consist of two

vertical poles with a sloping board nailed near their top. The slope rails define a plane parallel to

the proposed slope of the embankment, but at suitable vertical distance above it.

(OR) 7. (a) Write short notes on (6M)

i) Luminous signals ii) Phase of signals iii) Bilby tower iv) Helitropes

For Explaining each one with one or two sentences (1.5 M) (4x1.5 =6M)

Ans:

Luminous signals:

The signals which are used under light are called as luminous signals.

Phase of signals:

Phase of a signal is the error of bisection which arises from the fact that, under lateral

illumination the signal is partly in light and partly in shade.

Bilby tower:

A tower is erected at the triangulation station when the station or the signal or both are to

be elevated to make the observations possible form other stations in case of problem of

intervisibility.

Bilby towers patented by J.S. Bilby of the U.S. Coast and Geodetic Survey, are popular for

heights ranging from 30 to 40 m. This tower weighing about 3 tonnes, can be easily erected

by five persons in just 5 hrs.

Helitropes or Sun signals:

Sun signals reflect the rays of the sun towards the station of observation, and are also

known as heliotropes

7. (b) Write the factors to be considered for selecting the site for base line. (6M)

For writing the following six points (6M) (6 x1 = 6M)

The site should be fairly level or gently undulating. Highly undulating grounds should be

avoided. If the ground is sloping, the slope should be uniform and gentle.

The site should be free from obstructions throughout the base length. If the it has

obstructions, line clearing should not be difficult and costly.

The ground should be firm and smooth.

The two extremities of the base line should be intervisible.

The site should be such that well-shaped triangles can be obtained while connecting its end

stations to the main triangulation stations.

The site should be such that a minimum length of the base line as specified available.

UNIT -IV

8. a) Two tangents at chainage of 955 m. The angle of intersection is 150o. Calculate all

data necessary to setting out a curve of radius 150 m by the deflection angle method.

The peg intervals may b taken 15 m. Prepare a setting out table when the least count

of the vernier is 20". (6M)

Sol:

8 .b) Discuss the method of setting out a circular curve with two thedolites. What are its

advantages and disadvantages over Rankine’s method? (6M)

For drawing Figure – 1M

For Explaining the procedure – 3M

For writing any one or two advantages – 1M

For writing any one or two disadvantages – 1M

Procedure:

Advantages:

In two theodolite method, curves are staked out by angular measurements only.

Accuracy attained in this method is quite high.

Disadvantages:

This method is used when higher accuracy is required and when the topography is

rough or field condition is difficult.

(OR)

9. a) Explain in detail about applications of GIS in civil engineering. (6M)

For writing any six applications of the following (6 x1 =6M) (6M)

Ans:

Applications GIS:

GIS in Mapping

Telecom and Network services

Accident Analysis and Hot Spot Analysis

Urban Planning

Transportation Planning

Environmental Impact Analysis

Agricultural Applications

Disaster Management and Mitigation

Landslide Hazard Zonation using GIS

Determine land use/land cover changes

Navigation (routing and scheduling)

Flood damage estimation

Natural Resources Management

Soil Mapping

Land Information System

Tourism Information System

Irrigation water management

Worldwide Earthquake Information System

Deforestation

GIS for Public Health

Location Identification

Economic Development

Locating Underground Pipes and Cables

GIS for Wildlife Management

9. b) Explain in detail about GPS Satellite constellation and signals. (6M)

Ans:

A satellite constellation is a group of artificial satellites working in concert. Such a constellation

can be considered to be a number of satellites with coordinated ground coverage, operating

together under shared control, synchronized so that they overlap well in coverage, the period in

which a satellite or other spacecraft is visible above the local horizon.

GPS satellites fly in medium Earth orbit (MEO) at an altitude of approximately 20,200 km (12,550

miles). Each satellite circles the Earth twice a day.

The satellites in the GPS constellation are arranged into six equally-spaced orbital planes

surrounding the Earth. Each plane contains four "slots" occupied by baseline satellites. This 24-slot

arrangement ensures users can view at least four satellites from virtually any point on the planet.

The Air Force normally flies more than 24 GPS satellites to maintain coverage whenever the

baseline satellites are serviced or decommissioned. The extra satellites may increase GPS

performance but are not considered part of the core constellation.

In June 2011, the Air Force successfully completed a GPS constellation expansion known as the

"Expandable 24" configuration. Three of the 24 slots were expanded, and six satellites were

repositioned, so that three of the extra satellites became part of the constellation baseline. As a

result, GPS now effectively operates as a 27-slot constellation with improved coverage in most

parts of the world.

Head of the Department Subject Coordinator

Dr. Ch. Naga Satish Kumar Y. Ravi

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