IS 12891:1990 is the Indian Standard (BIS) for elastomeric bearings for bridges - specification. This standard specifies the material, design criteria, manufacturing, and acceptance testing requirements for elastomeric bearings used in road bridges. It covers plain and laminated bearings, designed to accommodate loads, translations, and rotations between bridge superstructures and substructures.
Earlier specification for material, design, manufacturing, testing, and acceptance requirements for elastomeric bearings in bridges.
Overview
- Status
- Superseded — superseded by IS 12891:2018
- Usage level
- Specialized
- Domain
- Structural Engineering — Bridges and Bridge Engineering
- Type
- Specification
- Amendments
- Reaffirmed 2003
Also on InfraLens for IS 12891
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! This code has been largely superseded in practice by IRC: 83 Part II for highway bridge projects governed by MoRTH/NHAI.
! The 'Shape Factor' is a critical parameter governing the bearing's load capacity and performance; it must be calculated correctly.
! Ensure bearings are sourced from a reputable manufacturer with proper test certificates as the acceptance testing (Clause 7) is rigorous.
Frequently referenced clauses
Updates & Amendments1 amendment
Consolidated list per BIS. For the text of each amendment, refer to the BIS portal link above.
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International Equivalents
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International Comparison — Coming Soon
We're adding equivalent international standards for this code.
Key Values7
Quick Reference Values
Minimum ultimate tensile strength of elastomer17 MPa
Minimum elongation at break of elastomer400%
Hardness of elastomer50-70 IRHD or Shore A
Typical shear modulus (G)0.8 to 1.2 MPa
Maximum average compressive stress10 MPa
Maximum shear strain due to permanent loads0.5
Maximum shear strain due to total loads0.7
Key Formulas
S = (Length x Width) / [2 x (Length + Width) x Thickness] — Shape factor for a rectangular pad
Ec = 5 G S^2 — Apparent Young's modulus of elastomer in compression
σc = P / A ≤ 10 MPa — Permissible compressive stress
Tables & Referenced Sections
Key Tables
Table 1 - Physical Properties of Elastomer
Table 2 - Tolerances
Key Clauses
Clause 4 - Materials
Clause 5 - Design
Clause 6 - Fabrication and Tolerances
Clause 7 - Testing and Acceptance Criteria
Frequently Asked Questions4
What is the main function of an elastomeric bearing?+
To safely transmit vertical loads from the superstructure to the substructure while accommodating translational and rotational movements caused by thermal changes, creep, shrinkage, and traffic.
What is the difference between a plain and a laminated bearing?+
A plain bearing is a simple elastomer block. A laminated bearing has internal steel plates bonded between elastomer layers, which constrains bulging and significantly increases its vertical load-carrying capacity.
What are the key material tests for the elastomer?+
Key tests include tensile strength, elongation at break, hardness, compression set, and accelerated ageing as specified in Clause 4 and Table 1.
Is this code still relevant for bridge design in India?+
While technically an active standard, for most national highway and major bridge projects, engineers must follow IRC: 83 (Part II) as mandated by the Ministry of Road Transport and Highways (MoRTH).
QA/QC Inspection Templates
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QA/QC templates coming soon for this code.