1.

Preliminary Scour Risk Assessment

1. Site Characterization

Bathymetric Survey: Conduct a detailed bathymetric survey to understand seabed topography.

Seabed Sediment Analysis: Analyze sediment composition (e.g., grain size, cohesiveness) to assess its susceptibility to erosion.

Metocean Data Collection: Collect data on currents, wave heights, and tidal ranges that affect sediment transport and scour potential.

2. Review of Historical Scour Data

Existing Studies: Review existing literature, similar projects, and historical scour data in the region.

Scour Case Studies: Analyze scour cases from similar marine environments to anticipate potential scour depths and patterns.

3. Initial Scour Depth Estimation

Empirical Scour Models: Use empirical or semi-empirical models, such as Sumer and Fredsøe’s equations, to estimate potential scour depth around the structure.

Sediment Transport Models: Assess sediment transport dynamics and erosion potential, factoring in wave and current effects on sediment motion around foundations.

Preliminary Numerical Modeling: Apply preliminary 2D or 3D computational fluid dynamics (CFD) models if needed, especially in complex environments, to understand flow and potential scour zones.

2.

Scour Protection System Design

1. Selection of Scour Protection Type

Rock Armor Layer: Commonly used for monopiles and jacket structures.

Concrete Mats or Blocks: Pre-fabricated concrete blocks or mats placed over the seabed.

Geotextile Sandbags or Mattresses: Geotextile bags filled with sand.

Hybrid or Customized Solutions: For complex sites, a combination of protection types may be used.

2. Dimensioning and Design of Protection Layers

Thickness and Layering:Design the thickness and layering of protection material based on anticipated hydraulic loads and scour depth predictions.

Filter Layer Design: Add a filter layer between the foundation and the main protection material to prevent sediment washout and ensure stability.

Material Sizing and Grading: Size and grade materials based on hydrodynamic conditions. 

3.Numerical Verification of Scour Protection Design.

Scour Protection Modeling: Use numerical models to test and verify the performance of the scour protection design

Impact of Protection on Sediment Transport: Model potential changes in local sediment transport patterns that may result from scour protection.

4. Physical Verification Testing (if necessary).

Scaled Model Testing in Laboratory: Test the design at a reduced scale in a controlled environment to assess stability.

3.

Monitoring and Maintenance

1. Post-Installation Monitoring

Scour Protection Monitoring: Perform bathymetric and sonar surveys to verify the effectiveness of the scour protection system immediately after installation and over time.

Sediment Movement and Scour Re-evaluation: Regularly monitor sediment movement and any scouring around the protected area, especially after extreme weather events.

2. Maintenance Planning

Inspection and Repair Schedule: Develop a schedule for regular inspections, based on the site’s exposure to dynamic environmental conditions.

Adaptive Maintenance Strategy: Plan for adaptive maintenance if monitoring reveals unexpected scour or material displacement, allowing for quick response and reinforcement if needed.