AMENDMENT NOTIFICATION NO. 9
Amendment No. 6/IRC:112/May, 2018 (Effective from the 30 th June, 2018) To
IRC:112-2011 – “Code of Practice for Concrete Road bridges” S. No. No.
1
Clau Clause se No. No. Page No.
For
11.3.2.3 (1) Curvature (Page 116)
Re a d Curvature
(1) For members with constant The curvature of any member may be calculated by symmetrical cross – sections (including using reinforcement), the following may be Eq.11.7 used: Eq.11.7 Where,
For simplication it can be assumed that the strain in k r is a correction factor depending on axial extreme compression ber εc reaches failure strain and can be taken as εcu2 and in the tension steel strain ε y load, cu2 reaches the yield strain ε yd k φ is a factor for taking account of creep. Where,
d = is the effective depth given in (2)
d is the effective depth in the plane of bending k r is a correction factor depending upon axial load as given in (3) k φ is a factor for taking account of creep as given in (4).
2
11.3.2.3(2) (Page 117)
(2) If all reinforcement is not concentrated on opposite sides, but part of it is distributed parallel to the plane of bending, d is dened as: Eq. 11.8
(2) For members with constant symmetrical cross section (including reinforcement) having reinforcement on both faces which reach the yield strains and are separated by lever arm, z = 0.9d, the curvature is given by as dened earlier. ε and d as yd
If all reinforcement is not concentrated on opposite Where i s is the radius of gyration of the sides, but part of it is distributed parallel to the plane total reinforcement area. of bending, d is dened as: Eq. 11.8 Where i s is the radius gyration of the total reinforcement area 3
11.3.2.3 (3) (3) K r in Expression (11.7) should be (3) As a simplication k r in expression (11.7) may be taken as: taken as 1.0 on the conservative side. Alternatively k r (Page 117) can be calculated as shown below: K r = (n ( nu – n) / (n ( nu – nbal ) ≤ 1 k r = (n ( nu – n) / (n ( nu – nbal ) ≤ 1 Eq. 11.9 Where Eq. 11.9 Where relative axial force. N ED = is the design value of axial force. nu = 1 +
ω
N ED = design value of axial force
nbal is the value of n at maximum moment nu = 1 + resistance; the value 0.4 may be used.
ω
AMENDMENT
S. No. No.
Clau Clausse No No. Page No.
F or
Read
nbal is the value of n calculated using the balanced axial force corresponding to the maximum moment of resistance of section which shall be obtained by A s = is the total area of reinforcement. constructing the Axial Load-Moment interaction Ac = is the area of concrete cross – section. diagram. For symmetrically reinforced rectangular sections nbal can be taken as 0.4.
Where A s = is the total area of reinforcement, and, Ac = is the area of concrete cross – section. 4
12.3.4 (2) Aceff is the effective area of concrete in (Page 126) tension surrounding the reinforcement of depth hcef where hcef is the lesser of 2.5 (h-d);(h-x)/3; or or h/2 (refer g 12.2)
Aceff For rectangular section it is the effective area of concrete in tension surrounding the reinforcement of depth hcef , where hcef is the lesser of 2.5 (h-d); (h-x)/3; or or h/2 (refer g 12.2) For circular section a thin slice in the plane of bending through diameter having width equal to spacing of reinforcement bars may be taken and analyzed. Ac,eff , hcef and ρ p.eff shall be calculated for this slice taking d as the effective depth of reinforcement in this width
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6
12.3.6
New Note
Add Note below table tabl e 12.3:
(Page 130)
“Table “Table 12.2 and 12.3 are applicable for circular section also.”
Clause 16.11.2 (3)
In order to avoid edge sliding, uniformly distributed reinforcement parallel to the loaded face should be provided to the point at which local compressive compress ive stresses are dispersed. This point is determined as follows:
In order to avoid edge sliding, uniformly distributed reinforcement parallel to the (Page 189) loaded face should be provided to the point at which local compressive compress ive stresses stress es are dispersed. This point is determined as follows: A line inclined at an angle θ (30º) to the direction of load application is drawn from the edge of the section to intersect with the opposite edge of the loaded surface, as shown in Fig. 16.10. The reinforcement provided to avoid edge sliding shall be adequately anchored.
A line inclined at an angle θ (30º) to the direction of load application is drawn from the edge of the section to intersect with the opposite edge of the loaded surface, as shown in Fig. 16.10. The reinforcement provided to avoid edge sliding (At) shall be calculated using the expression At f yd ≥ FRdu/2 and shall be adequately anchored on both sides of the failure plane. Reinforcement provided for other purposes may also be utilized for this requirement.
AMENDMENT/ERRATA NOTIFICATION NO. 10
Amendment No. 3/IRC:6/May, 2018 (Effective from the 30 th June, 2018) To
IRC:6-2017 “Standard “Standard Specications and Code of Practice for Road bridges, Section; II Loads and Load Cominations” (Seventh Revision) S. No.
Clause No.
F or
Re a d
Page No.
1
Clause 219
Seismic Force
Refer IRC:SP:114 IRC:SP:114 “Guidelines for Seismic Design of Road Bridges”
(Page 61 to 74)
NOTIFICATION NO. 11 Errata No. 1/2018 To
1.
IRC:SP:64-2016 “Guidelines for the Analysis and Design of Cast-in-Place Cast-in-Place Voided Sla Sla Superstructure (First Revision)” IRC:SP:66-2016 “Guidelines for Design of Continuous bridges (First Revision)” and IRC:SP:70-2016 “Guidelines for the use of High Performance Concrete (Including Self Compacting Concrete in Bridges) (First Revision)”.
2. 3.
S. No.
Clause No.
For
R e ad
2.0
Cl No.2.1
Deleted
(Page 2)
Cl No. 2.2
Deleted
Cl. No.2.3
2.1
Page No.
1
SEMINAR ON “INTRODUCTION “ INTRODUCTION TO NEw SEISMIC SEIS MIC GUIDELINES ON HIGHwAY HIGHwAY bRIDGES RD (IRC:SP:114-2018)” ON 23 JUNE 2018 AT PHD HOUSE, NEW DELHI Indian Association of Structural Engineers (IAStructE), national apex body of s tructural engineers in India is planned to organize half-day Seminar on topic “Introduction to Ne Seismic Guidelines on Highay bridges (IRC:SP:114-2018)” on 23rd June 2018 between 2:30 PM to 05:30 PM at PHD Chamber of Commerce & Industry, PHD House, 4/2 Shri Institutional Area, August Kranti Marg, New Delhi 110 016. The participation fee is Rs 1,000/- for non IAStructE members. Hoever, for IRC memers 25 % discount is available. For IAStructE members, there is no participation fee. The Seminar will be followed by high tea. The aim of seminar is to sensitize the bridge designers, proof checkers, authority engineers and client engineers about provisions/adoptability of recently published/released IRC’s) new document IRC:SP:114-2018 “Guidelines for Seismic Design for Road bridges”, (i,e. on May 4 th 2018 during IRC council meeting held at Aizawl) which is replacing existing seismic provisions of IRC:6-2017. The invited speakers in this seminar are the code makers themselves who were involved in making of this new guideline. In view of limited available seats, you are requested to quickly send your nomination along with the requisite fee, as applicable or nominate engineers from your organization/department latest by 5 th June, 2018. For further details and enquiry, you may contact the IAStructE Secretariat: Mr. Vikas Verma, Verma, Manager IAStructE, Tel: 011-45794829, 011-45794829, Email:
[email protected].
