What kind of structures does this code apply to?

It applies to maritime structures such as breakwaters, seawalls, jetties, piers, and piles exposed to wave action.

What methods are given for calculating pressure on a vertical wall?

The code provides Sainflou's formula for non-breaking waves and Minikin's method for the impact pressure of breaking waves (Clause 5).

How are forces on piles or slender cylinders calculated?

Forces on piles are calculated based on the principles of the Morison equation, which combines drag and inertia force components (Clause 7).

Does this code consider wave overtopping?

Yes, Clause 8 provides guidance and formulae for estimating the quantity of wave overtopping for different types of coastal structures.

IS 6120

: 1971

Criteria for Wave Loads on Maritime Structures

CurrentSpecializedGuidelinesWater Resources · Coastal and Marine Engineering

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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.

Key Formulas

Sainflou's formula — For wave pressure from non-breaking or reflected waves on a vertical wall

Minikin's method — For shock pressure from breaking waves on a vertical wall

Morison's equation principle — For calculating drag and inertia forces on cylindrical piles

Practical Notes

This is a foundational but dated code. Modern designs often supplement these empirical formulas with advanced numerical modeling (e.g., Boussinesq, CFD) for complex cases.

The selection of the appropriate formula (e.g., Sainflou vs. Minikin) is critical and depends on the wave conditions (breaking or non-breaking) at the structure's location.

The code requires detailed site-specific hydrographic data (bathymetry, design wave height, period, and direction) as primary input for the calculations.