The authors present a novel procedure for the automated rectification of side-scan sonar images. The traditional assumption of a flat seabed for the computation of the ground projection from the slant-range sonar data can later result in difficult geo-referencing and registration problems. Accurate rectification using actual seabed topography is required for precise integration of side-scan ima...

Long gravity waves or swell dominating the sea surface is known to be very useful to estimate seabed morphology in coastal areas. The paper reviews the main phenomena related to swell waves propagation that allow seabed morphology to be sensed. The linear dispersion is analysed and an error budget model is developed to assess the achievable depth accuracy when Synthetic Aperture Radar (SAR) dat...

Several factors can affect the response of steel catenary risers (SCR) around its touch down zone (TDZ). These include stiffness soil, soil suction force on riser TDZ, degradation with cyclic TDZ loading, etc. Riser strength and fatigue computation are usually performed considering flat seabed use rigid or linear (spring) interaction model. However, bathymetric information obtained for SCR lay ...

Except in the deep ocean, the seabed has a major influence on low-frequency acoustic propagation. The formulation of an adequate geoacoustic model of the seabed is therefore one of the most important tasks facing anyone carrying out acoustic propagation modelling to predict underwater sound levels in coastal and continental shelf waters. It is often assumed that seabed layering on scales signif...

In this study, a three-dimensional (3D) model is adopted to investigate the problem of fluid-seabed-structure interactions (FSSI) around offshore detached breakwaters. The Volume-Averaged Reynolds-Averaged Navier-Stokes (VARANS) equations are used simulate 3D fluid motion in vicinity breakwaters, including reflected, diffracted waves and non-linear turbulence. partially dynamic Biot’s (i.e., u−...

This paper presents a comparison study on the application of two electromagnetic inverse scattering algorithms, SEABED [1] and the synthetic aperture method, to experimental multi-static UWB (Ultra Wide-Band) radar data. A linear UWB antenna array with a wideband frequency (1.5-8 GHz) was used for the multi-static radar measurement in a realistic environment. The results clearly show the advant...

To investigate the wave- and current-induced seabed response near a fully buried subsea pipeline, two-dimensional coupled model for fluid-seabed-pipeline interaction (FSPI-2D) is developed within framework of COMSOL multiphysics. Different from previous studies, both wave-current nonlinear pipeline-soil contacts are considered in present model. In this paper, Biot’s consolidation mode used to g...

In this study, the hydrodynamic forces acting on the seabed around the pipeline in unidirectional ocean currents have been investigated numerically. Two types of seabed are considered, i.e., plane and distorted seabed. The influences of gap between pipeline and seabed on the distribution of forces along the seabed are studied in detail. Computational results show that the pressure at the upstre...

Scour is a phenomenon that occurs as a result of natural erosion by ground water flow and transport of seabed material. In this research, scour around the legs of marine structures is simulated using the FLOW3D.V.9.3™ commercial software. The general scour model consists of two components, namely, the lift and thrust forces. The drag force, that is inserted to the structure, is a combination of...

Propagation and reverberation of acoustic fields in shallow waters depend strongly on the spatial variability of seabed geoacoustic parameters, and lack of knowledge of seabed variability is often a limiting factor in acoustic modeling applications. However, direct sampling (e.g., coring) of vertical and lateral variability is expensive and laborious, and matched-field and other long-range inve...