IS 6120:1971 is the Indian Standard (BIS) for criteria for wave loads on maritime structures. This standard provides criteria and methods for calculating wave loads on various types of maritime structures. It covers the classification of waves and details procedures for determining wave pressure and forces on vertical walls, breakwaters, and cylindrical piles.
Lays down the criteria for calculating wave loads on various types of maritime structures.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Wave Theory Application | Simple criteria based on water depth, likely suggesting Airy or Stokes' second order theory. | Prescribes specific theories (Stream Function, Cnoidal, etc.) based on dimensionless parameters d/L and H/L (or a Le Méhauté diagram). | USACE CEM |
| Inertia Coefficient (Cm) for circular pile | Typically a single recommended value, e.g., 2.0. | Varies with Keulegan-Carpenter (KC) number and roughness; typically in the range of 1.2 to 2.0. | DNV-RP-C205 |
| Drag Coefficient (Cd) for circular pile | Typically a single recommended value, e.g., 1.2 for rough piles. | Varies with KC number, Reynolds number, and roughness; typically in the range of 0.6 to 1.2. | DNV-RP-C205 |
| Design Sea State | Deterministic regular wave of a specific height (H) and period (T). | Stochastic approach using a wave energy spectrum (e.g., JONSWAP) defined by significant wave height (Hs) and peak period (Tp) for a given storm duration. | DNV-RP-C205 |
| Force on Vertical Breakwater | Likely based on older empirical methods like the Sainflou or Minikin formula. | Recommends Goda's formula for non-breaking and breaking wave pressures, which provides a more detailed pressure distribution. | BS 6349-1-1 |
| Dynamic Analysis | Not explicitly covered; analysis is static. | Required if the structure's natural period is close to the wave period. Methods for calculating Dynamic Amplification Factor (DAF) are provided. | DNV-RP-C205 |