surveying sample questions and answers

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,

For O ff ice us e only Sub mission Date:……………………….

Q uest ion Paper V eri f ied by: Name:………………………………………… Signatu r e:………………………………………

PA RT - A

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Q.N

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Quest ions Ans wer key w ith marking scheme

1 Why no t "part to who le"? Give r eason. Who le to par t p r even ts accumulat ion o f

er r or s and help s to con tr o l and local i se

mino r err or s. part to who le makes work

uncont r o llab le at the end .

(2 marks )

2 The t r ue length of a l ine is known to be 500 meter s. The l ine

was again measu r ed wi th a 20m tape and found to be 502m.

What i s the cor rect leng th o f the 20m tape? l

19 .92m

(2 marks )

3 Map conven t ional signs f or benchm ark and con tou r s.

( 1 x 2 = 2 mark s)

4 State the ob ject o f running a tie l ine . To take the deta il s o f near by object s and

als o ser ves as check l ine .

(2 marks )

UN IT - I I

Q.N

oQuest ions

Ans wer key w ith marking scheme

5 Def ine the ter m Bear ing o f a l ine . H ow wil l you measu re

ar b i t rar y bearing?

Bear ing o f a l ine: i t s d ir ect ion r ela t ive to

a g iven merid ian. ( 1 mark)

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Measured using a theodolite or sextant.

(1 mark)

6 At a place the bearing of sun is measured at local noon and

found to be 175°15' .What is the magnitude and direction of

magnetic declination at the place?

4° 45'E

(2 marks)

7 When do you recommend plane tabling? i. for filling-in of the details between the

stations previously fixed by triangulation

or theodolite traversing.

ii. for small-scale or medium scale

mapping in which great accuracy in

detail is not required as for

topographical surveys.

(2 x 1 = 2 marks)

8 Give the methods of orienting a plane table. i. by magnetic needle

ii. by back sighting

iii. two point problem

iv. three point problem

(any 2 x 1 = 2 marks)

U NI T - I I I

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Quest ions Ans wer key w ith marking scheme

9 The obs erved r ead ing on a staff held at poin t A is 3 . 894 . I f the

er r or o f vert i cal i ty i s 16cm in a length o f 4m, f ind the er r or in

staff r eading .

0. 156m

(2 marks )

10 Find the combined co r rect ion f o r cu r vatu re and ref ract ion f o r

a d istance o f 4. 0km

Combined correction = 0.0673D2

= 1.077m

(2 marks)

11 How a h i ll and dep res sion can be di f fer ent ia ted using

con tou r ing?

Hi l l : a c lo sed contou r w i th one o r more

higher ones ins ide .

Dep res sion : a clos ed con tour l ine w i th

one o r mor e lower ones in side .

(2 x 1 = 2 marks )

12 Give the l imi ta t ions of S imps on ' s r u le . The rule is applicable only when the

total number of ordinates is odd.

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If there are even number of ordinates,

the area of last division must be

calculated separately and added to

equation.

(1x 2 = 2 marks)

U NI T - IV

Q.N o Quest ions Ans wer key w ith marking scheme

13 What are the fundamental lines o f a t r ansi t theodol i t e? i. the vertical axis

ii. the horizontal or trunnion or

transit axis

iii. the line of collimation or line of

sight

iv. Axis of plate level

v. Axis of altitude level

vi. Axis of striding level, if provided.

(2 marks)

14 Def ine err or of clo su re . If a closed traverse is plotted

according to the field measurements,

the end point of the traverse will not

coincide exactly with the starting point,

owing to the errors in the field

measurements of angles and distances.

such error is known as closing error.

(2 marks)

15 What i s the use o f Gale ' s t r aver se table? Travers e com pu tat ions ar e usually done

in a tabu lar fo rm known as Gale ' s tab le .

It i s us ed to balance the tr averse and also

used to f ind the area of the clo sed

tr averse .

(2 marks )

16 What i s no rth ing and south ing? Northing: The latitude of a line is

positive when measured northward and

is termed as northing.

southing: The latitude of a line is

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negative when measured northward and

is termed as southing.

(1x2 = 2 marks)

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17 The p rel iminary su r vey shou ld be car ried ou t wi th g r eat

pr eci sion . G ive reas on .

Prel iminary su r vey decides the f inal r ou te

and r ecommends on ly one rou te in

pr efer ence to o ther alter nat ive r outes .

18 What i s the vers ed sine o f a cu rve? Expr ess i t

mathemat ical ly.

The mid - or d inate o f the cu rve is al so

known as vers ed sine o f the cu rve.

(1 mark)

M = R vers in ∆/2

(1 mark)

19 Why are ver t ical cu rves p rov ided? When the slopes or grades intersect or

meet, the vertical curves are provided in

the vertical plane to join them so as to

avoid an abrupt change in the rate of grade.

(2 marks)

20 Lis t the r equ i r ements o f hyd r og r aph ic s ur vey. i. Bed profile

ii. Horizontal control

iii.Shore details

iv.Vertical control

(4 x 0.5 = 2 marks)

PART - B

UN IT - I


21( a) Class if y su r vey bas ed on i t s ob jective . i. Engineering survey: for

determination of quantities for

designing engineering works such

as roads, reservoirs and sewage

disposal or water supply.

ii. Military survey: for determining

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points of strategic importance.

iii. Mine survey: for exploring

mineral wealth.

iv. Geological survey: for

determining different strata in

earth's crust.

v. Archeological survey: for

unearthing relics of anquity.

(4 marks)

21 ( b) Wri te the d i ff erence betw een a map and p lan . G ive the

designat ion and rep res enta t ive fr act ion f or a l ine 135

meter s long r ep resen ted by 22 .5cm on p lan .

If the representation scale is small,

then called as map while it is called as

plan if the scale is large.

(2 marks)

6m and RF = 1/600

(2x1 =2 marks)

22 ( a) A chain l ine ABC cr osses a river . B and C being on the near

and distan t banks res pect ively . T he r espect ive bear ings o f C

and A taken at D, a po in t 60m measu r ed at r igh t ang les to

AB fr om B ar e 280° and 190°, AB being 32m, Find the

wid th of the river.

112.5m

(4 marks)

22 ( b) Exp lain the basic p r incip le o f cro ss staf f su rvey . The whole plot is divided into right-

angled triangles and trapeziums. The

area of individual triangles and

trapeziums are worked out and added to

get the area of the whole plot.

Geometric relations for computing area:

Area of triangle = ½ x base x

perpendicular offset

= base x mean offset

Area of trapezium = base x (sum of

perpendicular offsets)/2

= base x mean offset

(4 marks)

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Q.No Questions Answer key with marking scheme

23(a) Give the rules to calculate R.B from W.C.B for all the quadrants.

W.C.B between

Rule for R.B

Quadrant

0°and90°

R.B = W.C.B

NE

90° and 180°

R. B = 180° - W. C. B

SE

180° and 270°

R. B = W. C. B - 180°

SW

270° and 360°

R. B = 360° - W. C. B

NW

(4 x 1 = 4 marks)

23 ( b) Catego rize the err or s in compas s s ur vey wi th any th ree of

thei r causes.

i. Instrumental errors

· needle not straight

· pivot bent

· sluggish needle

· blunt pivot

· improper balancing weight

· plane of sight not vertical

· line of sight not passing through

center

ii. personal errors

· inaccurate levelling of compass box

· inaccurate centering

· inaccurate bisection of signals

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· carelessness in reading and

recording

iii. natural errors

· variation in declination

· local attraction

· magnetic changes in atmosphere

· magnetic storms.

(4 marks)

24(a) Describe concisely the components of a plane table outfit. i. the drawing board

· made of well seasoned wood like

teak or pine

· size: 40cm x 30cm to 75cm x 60cm

or 50 t0 60cm square

· mounted on tripod

ii. the alidade

· consists of metal or box wood

straight edge.

· may be plane or telescopic.

· accessories to plane table: circular

box compass, plumbing fork, water-

proof cover.

iii. Paper

· Should be tinted in faint green or

grey.

· Zinc or celluloid sheets used to work

in damp climates.

( 4 marks )

24(b) Brief the method of resection. For what purpose it is

chiefly used?

Method of resection:

· select a base line PQ on the ground.

· set the table at P.

· place the alidade along pq and orient

till Q is bisected.

· with the alidade sight R to be

resected.

· shift the table to R and backsight P.

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· sight the station Q and draw a ray.

· point of intersection of this ray and

previously drawn gives required

point r. (3 marks)

purpose:

used for establishing the instrument

stations only.

(1 mark)

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25 ( a)

Catego rize level l ing staves and s um marize the rela t ive

meri t s of them.

Catego ries:

· self-reading staff

· Target staff

(1 mark)

M er i ts :

i. Fineness of reading taken by

target staff is greater than self

-reading staff.

ii. Level man records readings in

case of self- reading. Staff

holder takes reading in case

of target staff.

iii. Readings from self-reading

staff can be taken easily and

speedily compared to target

staff.

(3 marks)

25 ( b) Fo r a certa in obser vation , the bubble w as ou t of center by 4

div i sions. The er ro r in staf f read ing held at a d istance o f

60m was found to b e0 .03m. i f the leng th o f one d iv i sion o f

the bubb le i s 2mm, f ind out the r ad ius o f cu r vatu re and

sens i tiveness of the bubble tube.

R = (4 x 1 60 )/ (500 x 0 .03 ) = 16m

(2 marks )

α1 = 25.78 s ec ond s.

(2 marks )

26 ( a)An observer standing on the bridge of a ship just sees the

mast of another ship. If the height of the observer’s eye

50 .47km.

(4 marks )

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above sea level is 38m, and that of the mast of the other

ship 48m, what is the distance between the two ships.

26(b) The areas within the contour lines at the site of reservoir and the face of the proposed dam are as

follows:

Contour in

m

100

103

106

109

112

115

118

Area

enclosed in

m2

1000

12800

16600

18800

24400

30600

38400

Assuming 100m as the bottom level of the reservoir and 118m as the water level, calculate the capacity

of the reservoir by Prismoidal formula.

370200m3 (4 marks)

UNIT - IV


27(a) Explain in brief about micrometer theodolites. · Micrometer theodolites are

provided with a micrometer fitted

with a microscope.

· Gives accurate results in short

time.

· Diametrically opposite readings

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are made visible at one position

with the help of optical

arrangements.

· Microscope is in the the form of

miniature telescope, With eye

piece, object glass and diaphragm.

· The object glass pointed to

horizontal circle throws the image

of a portion of the graduated arc

on it, in the plane of the

diaphragm.

· The box has window openings

both at top and bottom.

· This box also has fixed index

mark either in the form of an

arrow or a V-notch and a movable

slide carrying a pair of vertical

parallel hair-lines placed very

close together. A drum when

turned by the fine-pitched screw

operates the movable slide.

(4 marks)

27(b) How will you eliminate parallax in a theodolite? i. The eyepiece is focused, so that the

cross-hairs are seen clearly and

distinctly. The telescope is pointed

towards the sky or white paper is

held in front of the object glass. The

eye piece is moved in and out till the

cross hairs are seen clearly.

ii. The object glass is focused so that

the image of object is brought in the

plane of cross hairs and there is no

apparent movement of the image

when the observer moves his eye.

For this purpose, the telescope is

directed towards the object and the

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focusing screw is turned until the

image appears to be sharp and clear.

(4 marks)

28(a) How you would measure magnetic bearing of a line using

theodolite?

The theodolite should be provided with

either tubular compass or trough compass.

Set the instrument at P and level.

Set vernier to zero.

Loose clamp. Release the needle of the

compass. Rotate the instrument till

magnetic needle points north.

Using the lower tangent screw, bring the

needle exactly against the mark so that it

is in magnetic meridian.

Loose the upper clamp and point the

telescope towards Q. Bisect Q using

upper tangent screw. Read verniers A

and B.

Change the face and repeat steps 2, 3 and

4. The average of the two will give the

correct bearing of the line PQ.

(4 marks)

28(b) Write a short note on Bowditch's rule. · Also referred to as compass rule.

· Adopted when angular and linear

measurements are taken with equal

precision.

· As per rule, total error in latitude and

departure is distributed in proportion

to the lengths of the sides.

· Used in traverse adjustment and

expressed as follows:

CL = ΣLe (l/ Σl) and

CD = ΣDe (l/ Σl)

Where,

CL = correction to latitude of any side

CD = correction to departure of any side

ΣLe = total error in latitude

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ΣDe = total error in departure

l = length of any side

Σl = Length of the perimeter.

(4 marks)

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29 ( a) Di ff eren t ia te Reconnaissance su rvey and Locat ion sur vey. Reconnaiss ance su rvey :

Car ried ou t to study the deta i ls o f the

pr oposed p r oject or s cheme.

In fo r mat ion col lected is u sef ul dur ing

execu t ion of w ork .

Depends on the personal qual i t i es o f the

eng ineer

Shou ld be conducted acco rd ing to

gu id ing p r incip les than f ixed r u les.

Locat ion su r vey :

Car ries ou t the deta i led su r vey along the

rou te w h ich has been f ound and f ixed as

the most economical rou te fr om the data

of the p r eliminar y su rvey .

Af ter locat ion s ur vey, const ruct ion work

is star ted.

End o f locat ion s ur vey p roves to be the

start ing poin t o f the const ruct ion

act iv i t ies o f the p ropos ed p ro ject .

(4 marks )

29 ( b) D if fer en t ia te betw een M .B.M and T.B.M . MBM:

For a large pr o ject , a m aster bench mark

is es tab l i shed near the st ructu re . The

ex ist ing BM in the v icini ty o f the

st ructur e may be s elected as a M BM . But

if no such ex ist ing BM is avai lab le , the

MBM is estab l is hed by runn ing levels

fr om the nearby BM .

TBM:

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Depending on the size and shape of the

structure, required numbers of TBMs are

established near the structures. Existing

permanent structures are selected as

TBM. Concrete or masonry pillars can be

constructed to serve as TBM.

(4 marks)

30(a) Draw the typical shapes of the lemniscate curves for the

deflection angles of 60 and 120 .

(2 x 2 = 4marks)

30(b) Give reason: The setting out process of tunnels demands a

high degree of precision throughout the process.

The procedure in setting out tunnels

naturally varies according to local

conditions and it demands a high degree

of precision throughout the process. This

is due to the fact that the survey results

will not be available for checking unless

and until the bore is holed through and if

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something wrong is found at this stage, it

proves to be too difficult for any

correction.

Hence the job of tunnel surveying should

be entrusted only to experienced

surveyors in that field.

(4 marks)

PART - C

UNIT - I


31(a) Explain the sources of errors in chaining. i. Erroneous length of chain or tape.

ii. Bad ranging

iii. Careless holding and marking

iv. Bad straightening

v. Non-horizontality

vi. Sag in chain

vii. Variation in temperature

viii. Variation in pull

ix. Personal mistakes

(12 marks)

31 ( b) Exp lain the d i ff eren t m ethods o f chaining on slop ing

gr ound .

Methods:

1. Direct method

2. Indirect method

· Angle measured

· Difference in level

measured

· Hypotenusal allowance

(12 marks)

32 ( a) i . D escribe the method o f r ecip r ocal rang ing .

i i . A 20m chain used fo r a su rvey was found to be 20 .10m

at the beg inn ing and 20 .12m at the end o f the wor k.

The ar ea o f the p lan d raw n to a scale o f 1cm = 6m w as

meas ur ed wi th the help of a p lan imeter and f ound to be

50 .4 sq .cm. Find the t rue ar ea o f the f ie ld in sq .m. .

i. Reciprocal ranging

· Used when both the ends of the

survey lines are not intervisible.

· Two persons station at P1 and Q1

with ranging rods.

· The person at Q1 directs the

person at P1 to move a new

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position P2 in line with A and Q1.

·

The person at point P2 directs the

person at point Q1 in such a way

that he occupies the position Q2 in

line with P2 and B.

· the position is repeated until the

intermediate stations P and Q are

established.

(6 marks)

ii. Area = 1825sq.m

(6 marks)

32(b) i. What is well conditional triangle? Why is it necessary

to use well-conditioned triangles?

ii. What are the points to be observed while entering the

contents of a field book?

i. A well conditioned triangle has no

angle greater than 120 or smaller

than 30 .

The triangles are plotted by the method

of intersection of arcs. The

displacement of a point from its true

position is minimum, if it is

established by the intersection of two

arcs which intersect each other at 90 .

(4 marks)

ii. Points to be observed:

· All entries should be made in neat

hand-writing and all figures should

be legible.

· Each chain line should be written

on a separate page.

· References to other pages should

be clearly mentioned.

· Position of tie line should be

specified in the beginning and at

the end.

· Entries should be made in pencil.

· Date of survey work, name of

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project, index of chain lines and

stations, north line etc should be

written on the field work.

· Entries should not be crowded.

· Line showing object should not

cross the column of the field book.

· Measurements should be recorded

as soon as they are taken.

· Sketch of the object should not be

shown in advance.

· Stations should be indicated by

triangle and tie stations by circle or

an oval round.

· Writing in the field book should be

commenced from bottom to the top.

(8 marks)

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33 ( a) The fo l lowing bear ings w ere taken in running a compass t r aver se .

Line

F. B

B. B

A B

124° 30 '

304° 30 '

BC

68° 15'

246° 0'

CD

310° 30 '

135° 15 '

DA

200° 15 '

17° 45'

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At what stations do you suspect local attraction? Find the correct bearings of the lines and also

compute the included angles.

Local attraction: stations C and D.(1 mark)

Line

F.B

B.B

AB

124°30'

304°30'

BC

68°15'

248°15'

CD

312°45'

132°45'

DA

197°45'

17°45'

(5 marks)

Angle A = 106°45', Angle B = 123°45', Angle C = 64°30', Angle D = 65° (6 marks)

33(b) Draw a neat sectional elevation of a Prismatic compass. Give, in a tabular form, the difference between

prismatic compass and surveyor's compass.

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( 6 marks)

Item

Prismatic

compass

Surveyor's

compass

Magnetic

needle

Broad needle

type. needle

does not act as

index.

Edge bar type

needle. acts as

index also.

Graduated card

· graduat

ions are in

WCB

· graduat

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ions are

inverted

· graduat

ions are in RB

· graduat

ions are erect

Sighting vanes

· object

vane has metal

vane with

vertical hair.

· eye

vane has small

metal vane

with slit

· object

vane has metal

vane with

vertical hair.

· eye

vane has small

metal vane

with fine slit

Reading

· reading

taken with the

help of prism.

· sightin

g and reading

taking done

simultaneously.

· reading

taken directly

seeing through

the top of glass

· sightin

g and reading

cannot be done

simultaneously.

Tripod

May or may

not be

provided.

Cannot be used

without a

tripod.

(6 marks)

34(a) What is three point problem? How is it solved by Bessel's

method?

Three point problem:

Location of the position on the plan of

the station occupied by plane table by

means of observations to 3 well-defined

points whose positions have been

previously plotted on the plan.(2 marks)

Bessel's method:

· set the table at station P. keep alidade

on b a and rotate, A is bisected.

clamp the table.

· pivot alidade about b. sight C and

draw x y along edge of alidade.

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· keep the alidade along a b and bisect

B.

· pivot alidade about a and sight C.

draw along alidade edge to intersect

ray x y in c'. join cc'.

· keep alidade along c'c and rotate till

C is bisected.

· pivot the alidade about b and sight B.

Draw the ray to intersect cc' in p.

· the points a,b,c and p form a

quadrilateral and all 4 points lie on

the circumference of the circle. hence

known as Bessel's method of

inscribed quadrilateral.

(10 marks)

34 ( b) What i s meant by p lane tab l ing? State the meri t s and

demer i t s o f p lane tabl ing .

i. P lane t ab l in g:

A graph ical method of su rvey ing in

wh ich the fie ld w or k and p lo t t ing are

done simu l taneously . (2 mark s)

ii .

Merits :

Pa g e | 20

· suitable for preparing small scale

maps.

· rapid

· field book not necessary

· comparison of plotted work with

actual features is possible.

· no omission of measurements.

· error in measurement and plotting

detected by check lines readily.

· useful in areas where compass

survey is not possible.

· contours and irregular objects

represented accurately.

· less costly than theodolite survey

· no skill is required.

Demerits:

· a tropical instrument

· not suitable for wet climate

· heavy, cumbersome and awkward

to carry.

· several accessories carried and

therefore tend to be lost.

· not intended for accurate work.

· if survey to be replotted, it is a

great inconvenience in the

absence of survey notes.

(10 marks)

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35 ( a) During const r uct ion , the bo t tom of the slab was taken as a

temporar y BM with RL as 32. 752 . Fo l low ing no tes wer e

reco rded in the f ie ld book :

Read ing of inverted s taff on tempor ar y BM = 2. 630

Read ing on a staf f held on peg A on the gr ound = 1 . 725

The ins tr ument i s now s hi f ted and the r eading taken again

RL of B = 33. 907

(12 marks)

Pa g e | 21

on the staff held on peg A is 1.840 and the reading on

inverted staff at B is 3.670.

Calculate RL of B and enter the readings in level book form.

35(b) The following consecutive readings were taken with a

level and 4m staff on continuously sloping ground at a

common interval of 30m.

0.780, 1.535, 1.955, 2.430, 2.985, 3.480, 1.155, 1.960,

2.365, 3.640, 0.935, 1.045, 1.630 and 2.545.

The reduced level of the first point was 180.750. Rule out a

page of a level field book and enter the above readings.

Calculate the reduced levels of the points by the rise and

fall method, and also the gradient of the line joining the

first and last points.

179.995, 179.575, 179.100, 179.545,

178.050, 177.245, 176.840, 175.565,

175.455, 174.870, 173.955

(8 marks)

1 in 48.7 falling

(4 marks)

36(a) i. What is reciprocal leveling?

ii. Two points P and Q are situated on the opposite banks

of a river. When the instrument was near P, the

readings observed were 1.365 and 2.550 respectively.

When the instrument was near Q, the readings observed

on P and Q were 1.055 and 1.960 respectively.

Calculate a.) the true difference in level between P and

Q b) true RL of Q, if RL of P is 112.695 and c) the

total error due to curvature, refraction and imperfect

collimation adjustment.

i.When it is necessary to carry leveling

across a river, ravine or any obstacle

requiring a long sight betweentwo points

so situated that no place for the level can

be found from which the lengths of

foresight and backsight will be even

approximately equal, special method i.e,

reciprocal leveling must be used.

(3 marks)

ii.

a) 1.045m

b)111.65m

c)0.28m

(9 marks)

36 (b) Discuss various methods of interpolating the contours. Methods:

i. By estimation

Position of contour points

between guide points are located

by estimation.

ii. By arithmetic calculations

Time consuming.

iii. By graphical method

Done with the help of a tracing

P a g e | 22

paper or tracing cloth.

2 methods for graphical

interpolation.

(12 marks)

UNIT - IV


37(a) Describe in brief the permanent adjustments of a theodolite. i. To adjust the plate level

ii. To adjust the line of

collimation

iii. To adjust the horizontal axis

iv. To adjust the axis of the

altitude bubble

v. To adjust the vertical circle

vi. To adjust the striding level.

(12 marks)

37 ( b) How wil l you set ou t ho rizon tal angle by repet i t ion method?

State w hat err o rs are el iminated by r epeti t ion method .

To measu re ang le P QR:

· set the instrument at Q. set 00

reading on vernier A. note vernier B

reading.

· loose the telescope and direct

telescope towards P. Clamp and

bisect point P.

· unclamp upper and turn instrument

clockwise towards R.

· note the readings in both verniers A

and B to get angle PQR.

· unclamp lower and turn telescope

clockwise to sight P.

· unclamp upper, turn clockwise and

sight R.

· repeat until the angle is repeated for

3 times.

· the average angle with face left will

be equal to final reading divided by

3.

P a g e | 23

· change face and make three more

repetitions. find the average angle.

· average horizontal angle = average

of the angles taken with face left and

face right.

(8 marks)

Elimination of errors:

· due to eccentricity of verniers and

centers

· due to inadjustments of line of

collimation and trunnion axis

· due to inaccurate graduations

· due to inaccurate bisection of the

object, eccentric centering etc.

(4 marks)

38 ( a) Fo llow ing ar e the la t i tudes and depar tu res o f l ines AB, BC, CD and D A in a theodol i t e t r aver se:

Line

Lat i tude

D epartu re

AB

123 .35

35 .68

BC

93 .82

205 .86

CD

-177. 44

Pa g e | 24

70.11

DA

-39.21

-312.25

Adjust the traverse by applying the transit rule.

Line

Latitude

Correctio

n(-ve)

Correcte

d latitude

Departur

e

Correctio

n(+ve)

Correcte

d

departure

AB

123.35

0.15

123.20

35.68

0.03

35.71

BC

93.82

0.11

93.71

205.86

0.20

206.06

CD

-177.44

0.21

-177.65

Pa g e | 25

70.11

0.07

70.18

DA

-39.21

0.05

-39.26

-312.25

0.30

-311.95

(12 marks)

38(b) A closed traverse was conducted round an obstacle and the

following observations were made. Work out the missing

quantities.

Side

Length(m)

Azimuth

AB

500

98 30’

BC

620

30 20’

CD

468

298 30’

DE

?

230 0’

EA

?

150 10’

DE = 695.27m

EA = 273.99m

(12 marks)

Pa g e | 26

UNIT –V


39(a) Describe any six methods of location of the soundings. By cross rope

i. By intersecting ranges

ii. By one angle from the shore and

one from the boat

iii. By range and one angle from the

boat.

iv. By range and one angle from the

shore.

v. By range and time intervals.

vi. By tacheometry

vii. By two angles from the boat.

viii. By twor angles from the

shore.

(12 marks)

39(b) What is ground tracing? Explain in detail the setting out of

foundation trenches for buildings.

Ground tracing is the process of laying

down the excavation lines and center

lines etc on the ground, before

excavation is started.

(2 marks)

Setting out foundation using pegs:

· longest outer wall of the building is

first marked on ground with a string

between wooden pegs driven.

· this is reference line.

· two pegs each on either side of the

central pegs are driven at each end of

line.

· the distance between outer pegs

correspond to the width of foundation

trench to be excavated.

· Peg projects 25 to 50m above GL and

may be driven at a distance 5m from

the edge of excavation.

· The boundary is marked on the

P a g e | 27

ground with dry lime powder.

· A right angle can be set out forming a

triangle with 3, 4 and 5 units long

sides.

· A theodolite or prismatic compass

may be used for setting out right

angles.

Setting out foundation using masonry

pillars:

· reference pillars of masonry are

constructed of 20cm thick, 15cm

wider than the width of the

foundation trench.

· pillars are plastered and set at

plinth level.

· pegs are embedded in pillars to

represent center line and outer

lines.

· additional nails are provided to

represent plinth lines.

(10 marks)

40(a) Where is serpentine curve? Derive an expression for the

tangent of a serpentine curve between parallel straights.

Serpentine or reverse curve:

A compound curve having two circular

arcs of same or different radii, but

curving in opposite directions with a

common tangent.

(2 marks)

Expression:

T1T2 = 2(R1 +R2) sin(α/2)-------------(i)

X = (R1 +R2)versinα-----------(ii)

γ= (R1 +R2)sinα--------(iii)

Pa g e | 28

sin (α/2) = (X/( T1T2))-----(iv)

T1T2 = √(2X(R1+R2)----(v)

γ= 2Rsinα--------(vi)

T1T2 = 2√(RX)

(10 marks)

40(b) Derive the intrinsic equation of an ideal transition curve. Equation of a clothoid or Euler spiral

or True spiral:

Inclination of the tangent to the

transition curve α= L12 / 2RL radians

Spiral angle of transition curve α1=

L/(2R)

(12 marks)

Pa g e | 29

surveying sample questions and answers

Education