Seabed Stability Near Floating Structures

Abstract

A simple methodology is presented to examine the effects of fixed and floating structures on seabed stability. Liquefaction potential is estimated using Biot consolidation theory to model the dynamic soil response. Scour potential and stable grain sizes are determined from a simple incipient motion model. For a fixed structure, the potential for liquefaction and scour may be estimated from the incident wave conditions and the reflection coefficient. In general, the floating‐structure soil responses are smaller than those for the fixed case, except when the wave frequency is near the natural frequency of the structure. At the natural frequency, the liquefaction potential may be twice that of the fixed case and the stable grain size, an order of magnitude larger.