IRC 24-2010-1

AMENDMENT TO IRC:24-2010 Amendment No. 1 / IRC:24-2010/ January 2014 To IRC:24-2010 “Standard Specifications and Code of Practice for Road Bridges, Section V Steel Road Bridges (Limit State Method) (Third Revision) Sl.No.

Clause No. & Page No.

1.

504.3

2.

For

(Page 36)

The distance between centres of the main Replace “main girders” by “main outermost girders shall be sufficient to resist overturning girders” or over stressing due to lateral forces and loading conditions

504.4(b)

For rolled steel joists and plate girders

(Page 36)

(Page 37)

Beams and plate girders upto and including Substitute the following for the existing: 35 m span need not be cambered “It is not mandatory to camber beams and plate girders upto and including 35 m span”

507.5.1.2

Loaded through one Leg –

(Page 63)

The flexural torsional buckling strength of “in place of λ in clause 507.1.2.1 and using single angle loaded in compression through curve ‘C’ (α = 0.49) of Fig. 5” one of its legs may be evaluated using the equivalent slenderness ratio λe as given below:

IR

4.

504.6.2(a)

5.

Replace “plate girders” by “uniform depth plate girders”

C

3.

Read

509.3.1

Both flanges fully restrained

Table 12

Add the following at after the word ‘below’:

Substitute the following for the existing: “Both flanges partially restrained”.

(Page 86)

Second Column “Warping Restraint” Line 1

6.

509.3.1

In simply supported beams with intermediate lateral restraints against lateral torsional Para 2 buckling the effective length for lateral (Pages 86 & 87) torsional buckling to be used in Clause 509.2.2.1, LLT, shall be taken as the length of the relevant segment in between the lateral restraints. The effective length shall be equal to 1.2 times the length of the relevant segment in between the lateral restraints.

INDIAN HIGHWAYS, FEBRUARY 2014

Substitute the following for the existing: “In simply supported beams with intermediate lateral restraints against lateral torsional buckling, the effective length for lateral torsional buckling, LLT to be used in Clause 509.2.2.1 shall be taken as the length of the relevant segment in between the lateral restraints. In case of intermediate partial lateral restraints, the effective length LLT shall be taken as equal to 1.2 times the length of the relevant segment in between the partial lateral restraints.

101

AMENDMENT TO IRC:24-2010 Sl.No.

Clause No. & Page No.

7.

509.4.2.2(b)

For

tan-1(d/c)

Substitute the following for the existing:

⎛d ⎞ ⎜ ⎟ -1 ⎝ c ⎠ “nearly tan ” 1.5

(Page 94)

509.5.1 Fig.7 Note 2 (Page 95)

9.

514.4.5 (Page 170)

10.

514.5.9

Erection scheme of the bridge shall be checked to ensure the adequacy of the affected components of the bridge structure and safety of the bridge at all stages of erection.

Substitute the following for the existing: “All components of the bridge structure shall be checked against temporary forces, to which these will be subjected to during various stages of erection, to ensure safety during erection”.

The method of erection, as also the drawing Substitute the following for the existing: of the temporary work and the use of erection “The Engineer shall approve the procedure of equipment, shall be subject to the approval erection, drawings of temporary works and use by the Engineer. of erection equipment, prior to commencement of erection”.

IR

(Page 171)

Panel B is designed without utilizing tension Substitute the following for the existing: filed action as given in Clause 509.4.2.2(a) “Panel B is designed using simple post-critical method as given in Clause 509.4.2.2(a)”

C

8.

Read

102

INDIAN HIGHWAYS, FEBRUARY 2014