Roll No. ..~................... ,[Total No. of Pages: 03Total No. of Questions: 9]

I'

B. Tech. (Sem. - 6th)

DESIGN OF CONCRETE STRUCTURES -nSUBJECTCODE: CE-310

Paper'ID : [A0622](Note: Please fill subject code and paper.!D on OMR]

Maximum Marks: 60Time: 03 Hours

Instruction to Candidates:

1) Section -A is Compulsory.2) Attempt any Four questions from Section - B.3) Attempt any Two questions from Section - c.

Ql)

.a)

Section - A

(10 x 2 = 20)

When can a foundation be considered rigid? What will be the differencein action if the footing is flexible? ..

b) What is meant by eccentric loading on a footing and list the circumstancesunder which eccentric. load acts.

c)

d)

Where are beams curved in plan used?

With the aid of sketches, discuss in brief behaviour of cantilever retainingwall.

e) On a frustrum ofa spherical dome, show.linesoflongitudes and parallelsoflatitudes.

t)

g)

h)

Show plan and elevation of counterfort retaining wall.

What are the requirements for cover in water tanks?

Between smooth walls and ribbed steel, which would you prefer forwater tank construction?

i)

j)

What is a shear key?

Enumerate structural elements of an Intz type water tank.

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Section -'B

. (4 x 5 =20)Q2) A square footing 3.5 m x 3.5 m is used for a square column 300 x 300 mm

carrying a total ultimate load of 1500 kN. Safe bearing capacity/of soil is 100kN/m2. Using Grade M 20 &,Fe 415 steel, design the footing. .

. (a) as a pad footing of constant depth.. -

(b) as a sloped footing.

Q3) Design a strap footing for following data:

Column A 400 mm square carries 800 kN

Column B 600 mm square carries 1200 kN

Column A is on property line. c/c distance between columns is 8 m. SBC =150 kN/m2.Use M 20 & Fe 415 steel. .

Q4) Design a spherical dome for a circular room 10m in diameter with 200 mmthick side wall. Assume LL due to wind and accidental loading as 2600 N/m2on surface area. Take allowable stresses in tension in concrete = 2 MPa andcompression in concrete = 5 MPa, and tension and compressionin steel =120 MPa.Take rise of dome = 20m.

Q5) A 5 m square water tank is 3 m high. Th.etank is open atthe top and wallsrigidly fixed to the base which rests on firm ground. Use appro)\imateanalysis.AdoptM 30 & Fe 415.Assumereleyantstresses. .

Q6) For the following data, determine the preliminary dimensions of various. components & check the stabilityfor T shaped cantilever retaining wall :

Total height of earth to be retained is 6 m above bottom of base with level topand surcharge 1800 kg/m2

Unit weight of soil = 1500 kg/m3

Angle of repose of soil = 30°

SBC = 150 kN/m2

Coefficientof frictionbetweensoil andbase slab= 0.50 .

UseM 20 & HYSD Fe 415. ...

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Section -C(2 x 10 =20)

Q7) Design a counterfort retaining wall for the following data :

Spacing of cOUnterfort3 m.Surcharge angle = 15°

Angle of repose =28°

Unit weig4t of soil = 15kN/m3 . .Overall height = 7.~m ..Adopt M 20 concrete and Fe 415 steel.

Q8) What is a conical dome. Derive expression for meridional thrust and HoopForce. Design conical dome for the following data:Inside diameter of circular room = 18 m uniformly distributed load =2 kN/m2M 20 & Fe 415 to be used.

Q9) An underground water tank has an internal dimension of 4.5m x 4.5m x 3m.The top of tank is flush with the ground. Tank is supported by RCC slabresting on walls of the tank. The backfill around the tank has unit weight of16 kN/m3 and angle of repose = 30°. The water level during monsoons maygo up to a level of OAmbelow GL. .

....

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