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 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
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.