IS 1893:2014 Part 3 is the Indian Standard (BIS) for criteria for earthquake resistant design of structures - bridges and retaining walls. This standard covers the requirements for earthquake-resistant design of bridges, retaining walls, and earth-retaining structures. It provides guidelines on calculating seismic design forces, dynamic earth pressures, and hydrodynamic forces.
Lays down criteria for the earthquake resistant design of bridges and retaining walls.
Quick Reference — IS 1893 Part 3:2014 Bridges (Legacy)
Bridge importance factor, R-values per pier type, damping and seat-width references — legacy edition.
| Reference | Value | Clause |
|---|
| Scope | Bridges (legacy edition before Part 6:2022) | Cl. 1 |
| Status (April 2026) | Largely superseded by IS 1893 Part 6:2022 for new design | Foreword (2022 Pt 6) |
| Importance factor I — bridge classification | 1.0 (normal), 1.2 (important), 1.5 (large/critical) | Cl. 5 (Table 1) |
| Response reduction R — RC pier (ductile detailed) | 3.0 | Cl. 6 (Table 2) |
| Response reduction R — RC pier (ordinary) | 2.0 | Cl. 6 (Table 2) |
| Response reduction R — Steel pier | 2.5 | Cl. 6 (Table 2) |
| Response reduction R — Wall-type pier | 1.0 (transverse) / 3.0 (longitudinal) | Cl. 6 (Table 2) |
| Damping — RC bridges | 5 % | Cl. 5.3 |
| Time history — required for | Special bridges (cable-stayed, suspension, irregular) | Cl. 8 |
| Min seat width — superstructure | Per Cl. 11 (function of span and zone) | Cl. 11 |
| Vertical seismic component | (2/3) × horizontal | Cl. 7.4 |
| Liquefaction check — Zone III to V | Recommended for cohesionless saturated soils | Cl. 12 |
⚠ Largely superseded by IS 1893 Part 6:2022; included here for projects under earlier sanction. For new design, use Part 6 plus IRC 6.
Overview
- Status
- Current
- Usage level
- Essential
- Domain
- Structural Engineering — Disaster Resilience and Retrofitting
- Type
- Code of Practice
Also on InfraLens for IS 1893
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! Ensure hydrodynamic forces are included for bridge piers submerged in water bodies.
! Dynamic active and passive earth pressures for retaining walls must be evaluated considering horizontal and vertical seismic coefficients using the Mononobe-Okabe method.
! Response reduction factors (R) are highly dependent on the type of substructure, bearings, and ductility detailing.
Frequently referenced clauses
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International Equivalents
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International Comparison — Coming Soon
We're adding equivalent international standards for this code.
Key Values6
Quick Reference Values
Importance Factor (I) for important bridges1.5
Importance Factor (I) for normal bridges1.2
Zone Factor (Z) for Seismic Zone V0.36
Zone Factor (Z) for Seismic Zone IV0.24
Damping ratio for reinforced concrete bridges5%
Damping ratio for steel bridges2%
Key Formulas
Ah = (Z/2) * (I/R) * (Sa/g) — Design horizontal seismic coefficient
T = 2.0 * √(D/F) — Fundamental natural period of bridge
Tables & Referenced Sections
Key Tables
Table 1 - Zone Factor (Z)
Table 2 - Importance Factor (I) for Bridges
Table 3 - Response Reduction Factor (R) for Bridges
Key Clauses
Clause 5 - Seismic Design Force
Clause 6 - Design Response Spectrum
Clause 7 - Bridges
Clause 8 - Retaining Walls
Frequently Asked Questions3
What is the importance factor for bridges on major highways?+
1.5 for important bridges like those on National Highways (Table 2).
When must vertical seismic forces be considered?+
For bridges in Seismic Zones IV and V, bridges with large spans, or prestressed concrete bridges.
How is the horizontal seismic coefficient calculated?+
Using the formula Ah = (Z/2) * (I/R) * (Sa/g) as per Clause 5.1.
QA/QC Inspection Templates
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QA/QC templates coming soon for this code.