The pathogenicity of seven strains of Fusarium equiseti isolated from seabed soil was evaluated on different host plants showing pre and post emergence damage. Radial growth of 27 strains was measured on culture media previously adjusted to different osmotic potentials with either KCl or NaCl (-1.50 to -144.54 bars) at 15°, 25° and 35° C. Significant differences and interactive effects were obs...

Nature conservation and fisheries management often focus on particular seabed features that are considered vulnerable or important to commercial species. As a result, individual seabed types are protected in isolation, without any understanding of what effect the mixture of seabed types within the landscape has on ecosystem functions. Here we undertook predictive seabed modelling within a coast...

Free-span occurs normally in a pipeline at uneven seabed, dynamic seabed and pipeline crossing. Free spanning in pipeline causes Vortex Induced Vibration (VIV) fatigue, fracture and bursting. In this paper, a pipeline located in South Pars Gas Field is assessed against local buckling and VIV fatigue using probability of failure theory based on the recommended methodology by Det Norske Veritas (...

A frequency-wavenumber-domain formulation is presented in this paper for calculation of the Green's functions and wave propagation modes in a stratified fluid body underlain by a layered viscoelastic soil medium. The Green's functions define the solid and fluid displacements and fluid pressures due to uniform disk loads acting in either the soil or fluid media. The solution is in the frequency ...

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...

The traditional bucket foundation use vertical wall, which like a cup is buried upside down in seabed. A new bucket foundation with partial inclined wall has been proposed in this article. Based on limit equilibrium analysis of threedimensional stress state of foundation, the calculation method of the horizontal bearing capacity of the new bucket foundation has been deduced, which has been veri...

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 ...

We create a ’virtual-seabed’ platform to realize the 3D visual analysis of seabed on smartphone. The 3D seabed platform is based on a ’section-drilling’ model, implementing visualization and analysis of the integrated data of seabed on the 3D browser on smartphone. Some 3D visual analysis functions are developed. This work presents a thorough and interesting way of presenting seabed data on sma...

Uncertainty in seabed properties can lead to substantial uncertainties in acoustic propagation, of order tens of dBs. During this project, substantial progress was made in 1) quantifying seabed uncertainties, by developing an advanced seabed measurement technique and powerful commensurate methods to estimate the uncertainties and 2) predicting the effect of those effects on propagation by devel...

Acoustic seabed characterisation is known to make available very useful information for various marine related applications. Most existing single-beam echo sounder (SBES) classifications require ground truthing in order to have confidence in the final results and sometimes to relate labels to geological features. A statistical feature extraction approach, with an emphasis on quality control, is...