In this thesis a simplified method for dynamic response of jacket type offshore structures to extreme environmental load is investigated using existing experience and the procedures available within the industry. Fixed Jacket type offshore platforms may, under extreme wave loading conditions, exhibit significant nonlinear behavior. This must be accounted for in the design of such platforms, in order to ensure satisfactory structural safety. The complicated and nonlinear dynamic platform behavior implies that a wide number of significant uncertainties are introduced to the design process through the included mathematical models, analysis methods and the practical use of these methods. The major sources of nonlinear behavior are the wave loading, the damping mechanisms and the soil structure interaction. The inclusion of nonlinear dynamic platform behavior in the design process implies that nonlinear stochastic dynamic response based on time domain simulation methods must be applied. Time domain stochastic dynamic response analysis is an analysis method which will be a central element of the procedure. However, it seems not to be clear so far how this method should be integrated in a practical design procedure. Initially an overview of the different sources of nonlinear platform behavior is clarified with the underlying mechanism. Furthermore, it is outlined how those nonlinear effects may be accounted for with a special focus on estimation of extreme response and dynamic amplification factors. The discussion and outlines are illustrated by an example of fixed offshore platform. Finally the practical use of the method in the design of fixed jacket type offshore platforms is recommended.

In the second part of the study, the response of a jacket offshore platform is investigated accounting for foundation flexibility and the nonlinear behaviour of the supporting piles. The soil resistance to the pile movement is modeled using dynamic p-y curves, dynamic t-z curves and q-z curves to account for soil nonlinearity and energy dissipation through radiation damping. The response of fixed offshore structures to transient loading due to a range of wave loadings is presented. (Abstract shortened by UMI.).

A guide to the analysis and design of compliant offshore structures that highlights a new generation of platforms Offshore Compliant Platforms provides an authoritative guideto the analysis and design of compliant offshore structures and puts the focus on a new generation of platforms such as: triceratops, Buoyant Leg Storage and Regasification platforms. Whilst the authors – noted experts on the topic – include basic information on the conceptual development of conventional platforms, the book presents detailed descriptions of the design and development of new deep-water platforms. The book describes the preliminary design of triceratops in ultra-deep waters and presents a detailed analysis of environmental loads that are inherent in offshore locations such as wave, wind and current. The new methodology for the dynamic analysis of triceratops under ice loads, predominantly in ice-covered regions, is also examined with detailed parametric studies. In addition, the book covers the structural geometry and the various methods of analysis for assessing the performance of any other similar offshore platform under the special loads. A discussion of the fatigue analysis and service life prediction is also included. This important book: • Includes the analysis and design of compliant offshore structures with a focus on a new generation of platforms • Examines the preliminary design of triceratops in ultra-deep waters • Covers an analysis of environmental loads that are inherent in offshore locations such as wave, wind and current • Reviews the structural geometry and various methods of analysis for assessing the performance of any other similar offshore platform under special loads • Discusses fatigue analysis and service life prediction Written for engineers and researchers across engineering including civil, mechanical, structural, offshore, ocean and naval architecture, Offshore Compliant Platforms fills the need for a guide to new offshore platforms that provides an understanding of the behaviour of these structures under different loading conditions.

In historical background of oil and gas exploration industry, over years, fixed offshore platforms are widely used. In the design of fixed offshore structures, as known, they are always attacked by severe environmental loads especially dynamic wave loads which govern the design factor of the platform. In addition, they are found sufficiently rigid to withstand environmental loads in the open sea. However, if soil stiffness under seabed is taken into account, we know that soil layers are not acting as perfectly stiff foundation. Nonlinearity of soil stiffness with its property may affect the global structural stiffness and it is a time-dependent function of total forces at pile head. Therefore, natural frequency of structure becomes nonlinear and it may increase structural response or induce resonance. For design purpose, this book will give distinctively useful ideas to professional design engineers or students who are interested in methodology for modeling of non-linear foundation system of offshore structure. It is also recommended to researchers who would like to extend the scope beyond this book as recommended in the last section.

This book introduces readers to various types of offshore platform geometries. It addresses the various environmental loads encountered by these structures, and provides detailed descriptions of the fundamentals of structural dynamics in a classroom style, helping readers estimate damping in offshore structures and grasp these aspects’ applications in preliminary analysis and design. Basic concepts of structural dynamics are emphasized through simple illustrative examples and exercises. Design methodologies and guidelines, which are FORM based concepts, are explained through a selection of applied sample structures. Each chapter also features tutorials and exercises for self-learning. A dedicated chapter on stochastic dynamics helps students to extend the basic concepts of structural dynamics to this advanced domain of research. Hydrodynamic response of offshore structures with perforated members is one of the most recent research applications, and has proven to be one of the most effective means of retrofitting offshore structures. In addition, the book integrates the concepts of structural dynamics with the FORM-evolved design of offshore structures, offering a unique approach. This new edition is divided into seven chapters, each of which has been updated. Each chapter also includes a section on frequently asked Questions and Answers (Q&A), which enhances understanding of this complex subject through easy and self-explanatory text. Furthermore, the book presents valuable content with respect to new and recent research carried out by the author in structural dynamics. All numeric examples have been re-checked with more additional explanations. New exercises have been added to improve understanding of the subject matter. Computer coding is also included (wherever possible) to aid computer-based learning of the contents of the book. The book can serve as a textbook for senior undergraduate and graduate courses in civil, structural, applied mechanics, mechanical, aerospace, naval architecture and ocean engineering programs. The book can also serve as a text for professional learning and development programs or as a guide for practicing and consulting offshore structural engineers. The contents of this book will be useful to graduate students, researchers, and professionals alike.

This book provides detailed analysis methods and design guidelines for fire resistance, a vital consideration for offshore processing and production platforms. Recent advancements in the selection of various geometric structural forms for deep-water oil exploration and production require a detailed understanding of the design of offshore structures under special loads. Focusing on a relatively new aspect of offshore engineering, the book offers essential teaching material, illustrating and explaining the concepts discussed through many tutorials. It creates a basis for designing new courses for students of ocean engineering and naval architecture, civil engineering, and applied mechanics at both undergraduate and graduate levels. As such, its content can be used for self-study or as a text in structured courses and professional development programs.