Your Answer : (Not Answered)

Correct Answer : B

Intermediate vertical stiffeners safeguard the web against shear buckling stress.

The web of a plate girder is thin and deep, and diagonal compression from shear can make it buckle. Intermediate transverse (vertical) stiffeners divide the web into panels, raising its shear buckling resistance and allowing tension field action.

Concentrated loads are transferred to the web by bearing stiffeners at supports and load points. Buckling of the web under bending compression is prevented by longitudinal (horizontal) stiffeners. No stiffener is provided to increase self-weight.

Your Answer : (Not Answered)

Correct Answer : B

The slenderness ratio of lacing bars should not exceed 145.

IS 800 limits the slenderness ratio of lacing bars in laced compression members to 145, so that the lacing, which acts as a small strut carrying the transverse shear, does not buckle before the main member.

180 is the general limit for members carrying compression due to dead and imposed loads, so it is the trap; 120 and 100 are not the code's limit for lacing.

Your Answer : (Not Answered)

Correct Answer : A

The minimum pitch of rivets under IS 800: 2007 is 2.5d.

Clause 10.2.2 of IS 800: 2007 says the distance between centres of fasteners shall not be less than 2.5 times the nominal diameter of the fastener, to leave enough plate between holes and room to drive the rivets or tighten the bolts.

3.0d is a commonly used practical pitch, not the minimum, and 2.0d and 1.5d are below the code limit.

Your Answer : (Not Answered)

Correct Answer : C

The matching in the key is 1-C, 2-A, 3-D, 4-B. The triangle is the symbol of a fillet weld, the V-shaped line (a slanting line from a vertical one) is the symbol of a bevel weld, the circle is the symbol of a spot weld, and the open square bracket is used for the plug weld. The other options swap two or more of these, for example by calling the triangle a bevel weld or the circle a fillet weld.

Your Answer : (Not Answered)

Correct Answer : A

IS 800:2007 classifies steel cross-sections by their moment-rotation behaviour into four classes: plastic (class 1), compact (class 2), semi-compact (class 3) and slender (class 4). A rigid section is not one of these classes, so it is the odd one out. The plastic section can form a plastic hinge with the rotation needed for redistribution, the compact section can reach the plastic moment but with limited rotation, and the slender section buckles locally before the yield stress is reached.

Your Answer : (Not Answered)

Correct Answer : C

IS 800:2007 sets limits on the slenderness ratio of tension members. Where a member that normally carries tension can also undergo reversal of stress from loads other than wind or earthquake, the limits are 180 or 250 or 350 depending on the member. For the compression flange of a beam against lateral torsional buckling the limit is 300, which the key shows. The values of 180 and 250 are the limits for members that carry compression or are subject to stress reversal, and 400 is the limit for a tension member that is only a tie in a roof.

Your Answer : (Not Answered)

Correct Answer : D

For an angle connected through one leg, the net effective area (the older IS 800 formulation) is \(A_e = A_1 + kA_2\), where \(A_1\) is the net area of the connected leg, \(A_2\) the gross area of the outstanding leg, and \(k = 3A_1/(3A_1 + A_2)\). With \(A_1 = 200\) and \(A_2 = 160\):

The options with 160 as the first term use the outstanding leg as the connected one, and those with 25/29 use a wrong value of k.

Your Answer : (Not Answered)

Correct Answer : A

Under IS 800:2007 the distance between the centres of two consecutive fasteners in a line adjacent and parallel to an edge of an outside plate must not exceed 100 mm plus 4t or 200 mm, whichever is less, where t is the thickness of the thinner outside plate. In corrosive surroundings the limit is tighter. The other options give limits that are not those of the code: the expressions with 2t, or the 500 mm and 50 mm starting values, do not occur in it.

Your Answer : (Not Answered)

Correct Answer : B

IS 800:2007 gives the effective length of a compression member from its end conditions. For a member effectively held in position and restrained against rotation at one end, and restrained against rotation but not held in position at the other end (a sway, or translation allowed, with rotation fixed), the effective length is 1.2 L. The factor 0.65 L is for both ends held in position and fixed against rotation, 1.5 L is for one end held in position and restrained against rotation with the other held but not restrained, and 2.0 L is for the case of one end fixed and the other free.

Your Answer : (Not Answered)

Correct Answer : C

According to IS 800:2007, the thickness of flat lacing bars should not be less than one-fortieth of the effective length (the length between the inner end rivets or welds) for single lacing, and one-sixtieth for double lacing, where the bars are riveted at their crossing. The fractions of one-twentieth and one-thirtieth are thicker than the code requires, and one-sixtieth belongs to double lacing.

Your Answer : (Not Answered)

Correct Answer : B

A tie is not a compression member. A tie is a member that carries axial tension, such as the bottom chord of a roof truss or a hanger. A strut (a member in a truss or frame carrying compression), a rafter (the inclined roof member that is under compression and bending) and a boom (the long arm of a crane, which is compressed along its length when it lifts a load) are all compression members.

Your Answer : (Not Answered)

Correct Answer : D

The effective length of a compression member is \(l_e = k\,l\), where l is the unsupported length and k is the effective length ratio (the factor that depends on the end restraints). For example k = 2 for a column fixed at one end and free at the other and k = 1 for pin-ended. It is not a clear distance or the unsupported length itself, which is l, and calling it just a constant ignores the meaning in the code, which is the ratio of effective to actual length.

Your Answer : (Not Answered)

Correct Answer : D

In Euler's column theory the equivalent (effective) length of a column depends on its end conditions. A column fixed at one end and free at the other behaves like half of a column of twice the length which is pinned at both ends, so its effective length is \(2L\):

An effective length equal to L (10 m) applies to a column hinged at both ends, L/2 (5 m) to a column fixed at both ends, and \(L/\sqrt{2}\) (about 7.07 m) to a column fixed at one end and hinged at the other. These are the other options.