EA50JG: OFFSHORE STRUCTURAL DESIGN (2015-2016)

Course Aims

To introduce the student to some specialised fields of conceptual structural engineering design in an offshore context, and to develop confidence in these areas.

Main Learning Outcomes

By the end of the course students should:

A) have knowledge and understanding of:
• Environmental and transportation loads relevant to initial design of topsides modules
• the design of structural steelwork in offshore structures, and the requirements of relevant Codes of Practice
• Appropriate hand analysis techniques
• The requirements and techniques of site investigation offshore
• Shallow foundations
• Piled foundations
• Installation Methods
• The legislative framework applicable to decommissioning in the UKCS
• Techniques and equipment available for dismantling and removal of offshore structures
• Codified guidance for integrity calculations for decommissioned structures
B) have gained intellectual skills so that they are able to:
• visualise structural response and load paths
• understand the issues covered by Structural Codes of Practice
• approach the design problem logically and confidently
• understand the suitability of different foundation concepts with respect to soil conditions
• conceive a staged dismantling of offshore structures
C) have gained practical skills so that they are able to:
• perform quick initial analysis of module frameworks
• perform the necessary strength and stability checks according to Codes of Practice
• identify suitable geotechnical and geophysical tests required for the specific design
• identify different design methods used in shallow and piled foundations
• identify by hand analysis key integrity issues during piecemeal dismantling and removal
D) have gained or improved transferable skills so that they are able to:
• move between different Codes of Practice for structural engineering, by recognising the common issues underlying their different approaches
• Apply their knowledge of structural steel framing systems to other types of structures than Topsides Modules

Course Content

The course divides into three main topics.  The first topic will introduce the conceptual design of topside modules.  The second topic will introduce some key principles involved in the analysis and design of subsea foundations.  The third topic is a brief  introduction to key aspects of  structural decommissioning of offshore structures. The order of topic delivery may vary according to the availability of the lecturers.

Topsides Modules
This part of the course introduces the assessment and design of real-world topsides modules for offshore installations. It begins with the loading regime from load out to lift, and then describes the approximate hand calculation approaches required in the  initial conceptual analysis and design.  The use of the American Standard, AISC, will be briefly described, as will the use of pad-eye details for lifting points; and the issue of weight control. 

Offshore Geotechnics
Offshore site investigation - appreciation of geophysical and geotechnical site investigations and information obtained by each survey. Interpretation of CPT results relevant to offshore structures

Piled foundation – piled foundation is introduced and methods of different offshore pile types are explained. Depending on the soil type and behaviour during installation design methods for predicting axial capacity are introduced.

Shallow foundation – A brief overview of offshore shallow foundations types and applications of shallow foundations are introduced which are then followed by general design considerations for installations and in service ultimate limit state and serviceability limit state.

Structural De-commissioning
This part of the course begins with the legislative background to decommissioning in the UK Continental Shelf, before discussing the techniques available for the dismantling and removal of offshore structures.  The use of Appropriate Codes of Practice for Structural Integrity calculations  necessary to ensure that this process can be safely carried out forms the remainder of this part of the course.

Information on contact teaching time is available from the course guide.

More Information about Week Numbers

1st Attempt

1 three hour examination paper (100%)

Resit

1 three hour examination paper (100%)

Informal formative assessment is available to students during the weekly tutorial sessions.

Students will be able to request feedback on their exam performance within three weeks of the results being posted. 

The informal formative assessment is via the weekly tutorial sessions where students will be able to ask for feedback on their performance on the tutorial assignments.