Load factor is
Always equal to factor of safety
Always less than factor of safety
Always greater than factor of safety
Sometimes greater than factor of safety
Correct Answer :
C. Always greater than factor of safety
Related Questions
When the upper column does not provide full bearing area over lower column, the column splice is provided with the following assumption
Bearing plate is assumed as a short beam to transmit the axial load to the lower column section
Axial load is assumed to be taken by flanges
Load transmitted from the flanges of upper column and reactions from the flanges of lower columns are equal and form a couple
All the above
The use of tie plates in laced columns is
Prohibited
Not prohibited
Permitted at start and end of lacing system only
Permitted between two parts of the lacing
The critical load for a column of length I hinged at both ends and having flexural rigidity El, is given by
Pc = π²EI/l²
Pc = πEI/l²
Pc = πEI/I²
None of these
In a grillage footing, the maximum shear force occurs at the
Edge of grillage beam
Centre of base plate
Centre of grillage beam
Centre of base plate
The maximum axial load which is just sufficient to keep a column in a small deflected shape, is called
Crippling load
Buckling load
Critical load
All the above
The thickness of the web of a mild steel plate girder is less than d/200. If only one horizontal stiffener is used, it is placed at
The neutral axis of the section
2/3rd of the depth of the neutral axis from the compression flange
2/5th of the depth of the neutral axis from the compression flange
2/5th of the height of the neutral axis from tension flange
Rolled steel beams are:
Mainly used to resist bending stress
Used as independent sections to resist compressive stress
Used as independent sections to resist tensile stress
All the above
Long column is one
Which is more than 3 m long
Whose lateral dimension is less than 25 cm
Which is free at its top
Which has a ratio of effective length and least lateral dimension more than 15
Pick up the correct statement from the following:
Vertical stiffeners may be placed in pairs one on each side of the web
Single vertical stiffeners may be placed alternately on opposite sides of the web
Horizontal stiffeners may be placed alternately on opposite sides of the web
All the above
The least permissible clear dimension of the web of thickness t in the panel of a plate girder, is restricted to
150 t
160 t
170 t
180 t
Pitch of tacking rivets, when double angles connected back to back and acting as tension members should not be more than
500 mm
600 mm
1000 mm
300 mm
The ratio of hydrostatic stress to the volumetric strain within the elastic range, is called
Modulus of elasticity
Shear modulus of elasticity
Bulk modulus of elasticity
All the above
A compression member consisting of angle sections may be a
Continuous member
Discontinuous single angle strut
Discontinuous double angle strut
All the above
For the buildings having a low permeability, the internal wind pressure acting normal to the wall and roof surfaces is taken as
Zero
±0.2 p
± 0.5 p
±0.7 p Where p is basic wind pressure
The beams supporting the steps of a stair are generally known as
Headers
Trimmers
Stringers
Spandrel beams
In case of plastic design, the calculated maximum shear capacity of a beam as per IS: 800 shall be
0.55 Aw.fy
0.65 Aw.fy
0.75 Aw.fy
0.85 Aw.fy Where, Aw = effective cross-sectional area resisting shear fy = yield stress of the steel
The statical method of plastic analysis satisfies
Equilibrium and mechanism conditions
Equilibrium and plastic moment conditions
Mechanism and plastic moment conditions
Equilibrium condition only
With usual notations of the letters, the shear stress fs at any point of the cross-section is given by
fs =FQ/It
fs =Ft/IQ
fs =It/FQ
fs =IF/Qt
For a single section used as a tension member, the given area is assumed
20% to 30% in excess of the net area
30% to 40% in excess of the net area
40% to 50% in excess of the net area
50% to 60% in excess of the net area
A riveted joint may experience
Shear failure
Shear failure of plates
Bearing failure
All the above
The greatest permissible clear dimension of the web of thickness t in the panel of a plate girder, is restricted to
180 t
220 t
230 t
270 t
The effective length L of a simply supported beam with ends restrained against torsion, and also the ends of compression flange partially restrained against lateral bending, is given by
L = span
L = 0.85 span
L = 0.75 span
L = 0.7 span
A second horizontal stiffener is always placed at the neutral axis of the girder if the thickness of the web is less than
d/250 for structural steel
d/225 for high tensile steel
Both (c) and (b)
Neither (a) nor (b)
Lug angles
Are used to reduce the length of connection
Are unequal angles
Increases shear lag
All the above
When a tension member is made of four angles with a plate as a web, the allowance for holes is made as
Two holes for each angle and one hole for the web
One hole for each angle and one hole for the web
One hole for each angle and two holes for the web
Two holes for each angle and two holes for the web
Study the following statements. (i) Top lateral bracing prevents the sides-way buckling of the chord. (ii) Sway bracing keeps the rectangular shape of the bridge crosssection. (iii) Sway bracing transfers the load from top of end posts to bearings. The correct answer is
Only (i)
Both (i) and (ii)
Both (i) and (iii)
All (i), (ii) and (iii)
The allowable stress in axial tension is generally kept less if thickness of the member is more than
10 mm
12 mm
15 mm
20 mm
Strengths of a rivet in single shearing, in bearing and in tearing are 3425 kg, 4575 kg and 5025 kg respectively. If the load in the member is 35 tonnes, the number of rivets required, is
10
11
12
13
If d is the distance between the flange angles, the vertical stiffeners in plate girders are spaced not greater than
d
1.25 d
1.5 d
1.75 d
The critical stress on a column for elastic buckling given by Euler's formula, is
fc = π²E/(I/r)²
fc = (I/r)²/ πE
fc = (I/r)/ πE
fc = π²E/(I/r)