Univ., Diss.--Bremen, 2006.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 122-136).

Thesis (Ph.D.)--Memorial University of Newfoundland. / Typescript. Bibliography: leaves 166-172. Also available online.

Thesis (Ph. D.), Memorial University of Newfoundland, 1998. / Restricted until November 1999. Bibliography: leaves 194-199. Also available online.

Thesis (M.S.)--Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.

Thesis (Ph.D.)--Aberdeen University, 2008. / "Oceanlab" Includes bibliographical references.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980. / Supervised by Richard P. Von Herzen. Vita. Includes bibliographical references (leaves 223-226).

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980. / Supervised by Tanya Atwater. Vita. Includes bibliographical references (leaves 206-213).

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017. / In South Africa, squid fishing vessels need to find and then anchor above benthic squid egg beds to effect viable catches. However, waves acting on the vessel produce a dynamic response on the anchor line. These oscillatory motions produce impact forces of the chain striking the seabed. It is hypothesised that this causes damage to the squid egg bed beneath the vessels. Different mooring systems may cause more or less damage and this is what is investigated in this research. The effect of vessel mooring lines impact on the seabed during squid fishing is investigated using a specialised hydrodynamic tool commercial package ANSYS AQWA models. This study analysed the single-point versus the two-point mooring system’s impact on the seabed. The ANSYS AQWA models were developed for both mooring systems under the influence of the wave and current loads using the 14 and 22 m vessels anchored with various chain sizes. The effect of various wave conditions was investigated as well as the analysis of three mooring line configurations. The mooring chain contact pressure on the seabed is investigated beyond what is output from ANSYS AQWA using ABAQUS finite element analysis. The real-world velocity of the mooring chain underwater was obtained using video analysis. The ABAQUS model was built by varying chain sizes at different impact velocities. The impact pressure and force due to this velocity was related to mooring line impact velocity on the seabed in ANSYS AQWA. Results show the maximum impact pressure of 191 MPa when the 20 mm diameter chain impacts the seabed at the velocity of 8 m/s from video analysis. It was found that the mooring chain impact pressure on the seabed increased with an increase in the velocity of impact and chain size. The ANSYS AQWA impact pressure on the seabed was found to be 170.86 MPa at the impact velocity of 6.4 m/s. The two-point mooring system was found to double the seabed mooring chain contact length compared to the single-point mooring system. Both mooring systems showed that the 14 m vessel mooring line causes the least seabed footprint compared to the 22 m vessel.

Seabed stability in the vicinity of those offshore structure, which has been one of the particular concerns in engineering practice, can be compromised by the action of energetic waves. This project investigates the mechanisms of wave-induced soil response and liquefaction in a porous seabed near offshore structures. For this purpose both 2-Dimensional (2-D) and 3-Dimensional (3-D) integrated Wave-Seabed-Structure Interaction (WSSI) models have been developed within the project. They were used to simulate the effect of nonlinear wave-structure interaction on dynamic soil response in the neighbourhood of offshore pipelines, mono-pile structures, and multi-cylinder structures. Prior to applying the proposed WSSI models to practical engineering cases, several validations, mainly including wave and soil validations, were conducted. Excellent agreements between numerical and experimental results indicate the capacity of proposed WSSI models to simulate nonlinear wave-induced seabed response around offshore structures. Hereafter, the verified WSSI models are adopted to explore the mechanism of storm wave-induced soil response near offshore structures. The study of the offshore pipeline partially or fully buried in the seabed has shown that the leewake vortex can be sufficiently avoided with enough embedment, which also leads to lower possibility of the onset of scour in adjacent area of pipeline and the reduction of possible momentary liquefaction depth under pipeline bottom. Nonlinear wave-induced seabed response around a mono-pile structure, was investigated using the 3-D WSSI model developed in OpenFOAM, which allows to run numerical WSSI simulations in parallel. It was shown that, for waves propagating in a given longitudinal direction, the liquefaction occurs with greater depth at the lateral sides of mono-pile structure than at the front and back sides of mono-pile structure. Increasing penetration depth of the mono-pile structure slightly reduces the adjacent liquefaction depth. By adopting the same 3-D WSSI model, the numerical investigation of wave-induced soil response in the proximity of a multi-cylinder structure has been conducted. As found in the analysis by using same wave parameters in the case of a mono-pile structure, the nonlinear interaction between waves and multi-cylinder structure may significantly alter the distribution of liquefaction depth around each cylinder, compared to that for a single cylinder. Moreover, considering the effect of incident wave angles, such as 0° and 45° wave headings, it can be noted that the downstream cylinders are better protected from liquefaction threat due to the presence of upstream cylinders.