This code specifies the criteria and methodology for the earthquake-resistant design of concrete, masonry, earth, and rockfill dams and embankments. It provides guidelines for evaluating design seismic coefficients, hydrodynamic pressures, and performing both pseudo-static and dynamic analyses.
Specifies criteria for earthquake resistant design of various types of dams and embankments.
Quick Reference Values
Importance Factor (I) for dams1.5
Damping ratio for concrete/masonry dams (DBE)5%
Damping ratio for concrete/masonry dams (MCE)7%
Damping ratio for earth/rockfill dams (DBE)10%
Damping ratio for earth/rockfill dams (MCE)15%
Key Formulas
p = C * αh * w * h — Hydrodynamic pressure at depth y using Zangar's method
T = 2.9 * H / Vs — Fundamental natural period of vibration of an earth or rockfill dam
αh = (Z/2) * (I/R) * (Sa/g) — Design horizontal seismic coefficient
Practical Notes
Dynamic analysis is mandatory for dams exceeding 15m in height in Seismic Zones IV and V, and for dams exceeding 30m in Zones II and III.
Hydrodynamic pressure computations must account for both horizontal and vertical earthquake forces, often utilizing Zangar's method.
Site-specific seismic studies (yielding site-specific spectra) are highly recommended for large or critical dams rather than relying solely on the generalized codal spectra.