Rock dump stability study

Surveys had shown several spans on a pipeline in the southern North Sea and rockdumping had been proposed to rectify them. Rockdumping is a recognised method of span rectification, providing protection and support for the spanning section of pipeline.

The purpose of this study was to consider the stability of these rockdumps in order to prevent further pipeline exposure and spanning, considering 1-year, 50-year and 100-year storm events.

This study determined:

• A suitable rock size range to ensure stability of the rock dumps
• The need for monitoring of the rockdump
• Repair methods should the rockdump show signs of movement

This enabled the rapid rectification of the spanning sections and provided confidence in their durability.