B.Arch-B.Arch Architecture 8th Sem THEORY OF STRUCTURES - III(University of Pune, Pune-2013)

THEORY OF STRUCTURES - III

(2003 Pattern)

Time : 3 Hours]                                                                                         [Max. Marks : 100

Instructions to the candidates :

Answer any three questions from each section.

Answers should be written in separate answer books. Neat diagrams must be drawn wherever necessary. Figures to the right indicate full marks.

Use of non programmable calculators and steel tables allowed. Assume suitable data if necessary.

Use Fe 415 steel and M20 grade concrete.

SECTION - I

Trial Pits and Bore Holes.

Counterfort Type Retaining Wall.

Reinforcement Detailing of a Folded Plate Staircase. Raft Foundations.

Rankine’s Theory of Earth Pressures - Basic Assumoptions, Active and

Passive Earth Pressure.

Piles - Need and their structural Action.

Q2) A rectangular column of size 230 × 450 is subjected to a factored load of

1100 kN and rests on a soil of S.B.C of 300 kN/m2.

a) Design the base of the isolated footing and draw a diagram showing the

geometry.                                                                                                             [4]

b) Find depth for B.M. considerations and find steel required for same.[4]

c) Draw a plan and section showing the reinforcement.                           [3]

d) If the said footing is near another column of same size and load with a

centre to centre distance of 1.8 m, would it be necessary to provide a combined footing. If so design the size of the rectangular combined

footing in plan only.                                                                                            [6]

P.T.O.

Q3) Design a R.C.C doglegged staircase for an office building for the following

data :                                                                                                                          [17]

Width of the flight - 1500 mm

Floor to floor height - 3200 mm Tread - 275 mm Riser - 160 mm

The staircase is supported on 230 mm wide beams on outer edges of

landings.

Q4) A retaining wall is of the following data.

Retained earth is on the vertical face of the stem.

Density of retained earth 18 kN/m3

Angle of repose - 30 degrees

Coefficient of friction - 0.6

S.B.C of soil - 250 kN/Sq. m

Density of Concrete - 25 kN/m3

Top Width of stem - 400 mm

Bottom width of stem - 850 mm

Height of stem - 5500 mm Width of base - 3200 mm Toe Projection - 900 mm Depth of Base - 600 mm

a) Check the stability of the above wall with regards to Overturning and

Sliding.                                                                                                               [11]

b) Find the Maximum and Minimum Pressure at the base and comment on

the same.                                                                                                              [6]

SECTION - II

Q5) a) What are the advantages of Prestressed R.C.C construction over

conventional R.C.C construction.                                                             [8]

OR

a) Explain Pretensioning and Post Tensioning.                                           [8]

b) A prestressed concrete beam of overall size 300 × 600 is simply supported

over a span of 6.5 m. The beam carries an udl of 18 kN/m over its entire span inclusive of its self weight. The prestressing tendons are located at a distance of 200 mm from the neutral axis and provide a prestressing force of 1100 kN.

Calculate the extreme fibre stresses at mid span.                                [9]

[4367]-33                                                         2

Q6) a) Design a purlin for a factory building for the following data :

i) Span of the truss - 16 m

ii) Spacing of the trusses - 4.5 m

iii) Slope of roof 25º

iv) Spacing of purlins - 2.2 m

v) Take dead load as 200 n/M2

Use angle section.

b) Write short notes on any two :

i) Castellated Girders - Need and Advantages.

ii) Plate Girder - Need and Different Parts.

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