Bengal Engineering and Science University 2007 B.E Civil Engineering Design of Structure-II - Question Paper

the ques. paper is with the attachment.

Ex/BESUS/ CE-602/07 B.E. (CE) Part-Ill 6th Semester Examination, 2007

Design of Structure-II

(CE-602)

Time : 3 hours    Full Marks : 100

Use separate answerscript for each half. Answer SIX questions, taking THREE from each half. Two marks are reserved for neatness in each half. Assume any data, suitably, if reguired.

FIRST HALF

Calculate the stresses developed at the section of a gantry girder made with ISMB450 and ISMC250 for crane capacity = lOOkN, crab weight = 20kN and maximum static wheel load = 200 kN, span of Gantry Girder = 6 m. Assume wt of Gantry girder = 1.5 kN/m. Assume wheel base = 2 m.

Sectional properties ISMB 450

w = 72.4 kg/m, Zyy = 111.2 cm3, tw = 9.4 mm Yxx = 73.3 mm ISMC 250 Yyy w = 30.4 kg/m, Zyy = 38.4 cm3, tw = 7.1 mm = 23.8 mm Yyy

a = 9227 mm1, bf = 150 mm, Ixx = 30390.8 cm4 = 25.9 mm a = 3867 mm2, bf = 80 mm, Ixx = 3816.8 cm4 Cyy = 23 mm

Zxx = 1350.7 cm3 tf = 17.4 mm Iyy = 834 cm4 305.3 cm3 Jxx tf= 14.1 mm Iyy = 219.1 cm4 [161

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3.    Design a combined footing for supporting two columns of size 300 x 300 mm each, carrying axial loads of 900kN and HOOkN. The columns are spaced at 3.5m centre to centre. The bearing capacity of soil is 120kN/m². Use M20 & Fe415 grades of concrete and steel. Design for flexure only.    |16|

4.    a) Design and detail the longitudinal beam (as singly reinforced rectangular beam)

of a slab-beam type combined footing for the two columns A (400 mm square, carrying 240 kN axial load), B (300 mm square, carrying 150kN axial load), situated at a centre line distance of 1.56 m apart in a building. Due to property line restriction, the foundation can not be extended 640 mm beyond the centre line of column B. The safe bearing of soil is 70 kN/m². Take permissible shear stress as 0.4 MPa. Use M20 grade concrete and Fe415 grade steel.

b) Prepare suitable layout of a trapezoidal footing for the two columns of Question 4(a). Given, the property line are 640 mm and 700 mm beyond the face of B and A, respectively.    |10+6|

5.    Design a suitable pile cap to support column of size 500 mm x 500 mm, carrying an axial load of 600 kN. The maximum capacity of 400 mm & 500 mm diameter piles are 150kN and 200kN respectively. Use M25 grade concrete and Fe415 grade steel. Take permissible shear stress as 0.35 MPa.    [161

SECOND HALF

6.    Design a column base of a column having section as ISHB 300 @ 0.588 kN/m and carrying an axial load of 350kN with a moment of 45 kN-m in the plane of web. The allowable pressure on the footing is 4 MPa. For ISHB 300, given that a = 74.8 cm², b = 250 mm, tf = 10.6 mm, t_w = 7.6 mm.    [16]

7.    A simply supported welded plate girder of span 24 m is made up of 2200 mm x 12 mm web plate and 500 x 50 mm flange plates. The girder carries a u.d.l. of 40 kN/m, inclusive of self-weight. Design the end bearing stiffener.    |16]

8.    Design the mid-span section of a simply supported welded plate girder, carrying a uniformly distributed load of 80 kN/m, exclusive of self-weight, on an effective span of 25 m. Check both the flexural stresses and shear stresses, considering permissible stress as arc = 145 MPa.    (16]

9.    Design a suitable rivetted web splice at one third span of the plate girder with span and loading as mentioned in (Q.8), with the following components of the plate girder : (i) Flange plate = 2 nos. 500 x 10 mm; (ii) Web plate = 2200 x 8 mm,

(iii) Flange angles : 2 nos. ISA 125x95x 12 at each flange plate, (iv) 18mm power driven rivets.    [ 16]

10.    An ISHB 300 @ 58.8 kg/m column carries an axial load of 500 kN. The column has to be spliced at a section, which is subjected to a moment of 15 kN-m, about the X-X axis of the section. Design the splice. Use 20 mm diameter rivets. |16]

1

A bracket supporting a gantry girder is connected to a steel column of ISHB 450 @ 92.5 kg/m at the height of 3.5 m from base of the column, maximum vertical forces from gantry girder = 150kN, which is acting at a distance of 175 mm from column face. Axial load on column = 200 kN. Effective length = 4.5 m. Check the adequacy of the given section.

26 5 x 10⁵

Assume C_xx = C_my = 0.85 & f_cb = -- MPa

For ISHB 450 @ 92.5 kg/m

a = 11789 mm²,    Z_xx = 1743.1 cm³    Z_yy = 242.1 cm³,

b_f = 250 mm,    t_f = 13.7 mm    t_w = 11.3 mm

I_xx = 40349.9 cm³, Iyy = 3045 cm⁴    y_xx = 18.5 mm [16|

Attachment: bengal-engineering-and-science-university-2007-b-e-civil-engineering-1092-1.pdf

Earning:   Approval pending.