IS 1893:2022 Part 6 is the Indian Standard (BIS) for criteria for earthquake resistant design of structures - bridges. This code provides criteria for the earthquake-resistant design and analysis of bridges, viaducts, flyovers, and aqueducts, including the determination of seismic base shear, hydrodynamic forces on submerged piers, and ductile detailing requirements.
Establishes criteria for earthquake resistant design of bridges, covering seismic forces, analysis methods, and detailing requirements.
Importance factor, R-values, time-history triggers, vertical seismic, SSI and seat-width requirements for bridges.
| Reference | Value | Clause |
|---|---|---|
| Scope | Earthquake-resistant design of bridges (cable-stayed, suspension, arch, special) | Cl. 1 |
| Status | Replaces / supersedes IS 1893 Part 3:2014 for advanced bridges | Foreword |
| Cross-reference (regular bridges) | IRC 6 + IRC 112 + IRC 78 (with seismic clauses) | Cl. 1.2 |
| Importance factor I — strategic bridges | 1.5–1.75 | Cl. 6 (Table) |
| Importance factor I — important bridges | 1.2 | Cl. 6 (Table) |
| Importance factor I — normal bridges | 1.0 | Cl. 6 (Table) |
| Response reduction R — substructure types | 1.0 (elastomeric isolation) to 5.0 (ductile RC pier) | Cl. 7 (Table) |
| Damping — RC bridge superstructure | 5 % | Cl. 5.4 |
| Damping — cable-stayed (cables) | 1–2 % | Cl. 5.4 |
| Time history analysis — required for | Special / irregular / >150 m span / Zone IV–V critical | Cl. 8.2 |
| Vertical seismic component — when included | Long span / cantilever / Zone IV–V | Cl. 6.4 |
| Soil-structure interaction — required for | Soft soil / deep foundations / well foundations | Cl. 9 |
| Liquefaction screening — Zone III–V | Mandatory for sites with loose saturated cohesionless soils | Cl. 10 |
| Min seat width — superstructure (no isolators) | Per Cl. 11 / IRC 6 (function of L, span, zone) | Cl. 11.1 |
| Capacity-design ratio — pier/foundation | Foundation must remain elastic at pier overstrength | Cl. 12 |
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.