88283 - OFFSHORE GEOTECHNICAL ENGINEERING

Conoscenze e abilità da conseguire

Aim of the course is to provide students with the ability to apply their knowledge and experience of soil mechanics and geotechnical engineering to offshore developments. In particular, the course covers the geotechnical properties of seabed sediments, the offshore site investigation procedures together with the traditional and advanced approaches for the design of a wide range of offshore foundations.

Contenuti

The course builds on student's previous knowledge of soil mechanics and addresses the geotechnical engineering aspects of the design of offshore structures with application to oil and gas and wind turbine developments. The course is organised in three modules as follows.

Module I (from 19/09 to 24/10)

Introduction. Short history of offshore developments in Italy and worldwide. Overview of offshore structure and foundation types. Features of the offshore environment: met-ocean data, sediments and hydrodynamic regimes.

Behaviour of a soil element. Summary of fundamentals: compression and shear. Cyclic loading: essential features, laboratory modelling of cyclic loading, cyclic resistance curves, failure and deformations under cyclic loading.

Site investigation. Overview on investigation systems. Sampling. Penetration tests: cone (CPT), T-bar and ball penetrometers: equipment, procedures and data interpretation.

Module II (from 31/10 to 12/12)

Design of piles. Overview. Essential features of driven steel piles: plugging, friction fatigue. Resistance to driving. Axial and lateral capacity of driven piles in clay and sand. Axial and lateral response of driven piles: load transfer curves in clay and sand.

Module III (from 02/03 to 05/06)

Design of shallow foundations. Overview. Shallow foundations types. Features of installation methods. Classical bearing capacity theory: uniaxial and general loading conditions. Interaction diagrams. Shallow foundations load-displacement response under general loading conditions.

Design of anchor foundations. Overview. Anchor and mooring types. Installation features. Estimate of anchors capacity under combined loading.

Design principles according to American Petroleum Institute (API), International Standard Organisation (ISO) and Det Norske Veritas (DNV).

Testi/Bibliografia

Mark Randolph and Susan Gourvenec, Offshore geotechnical engineering, Spon, 2011

Subhamoy Bhattacharya, Design of foundations for offshore wind turbines, Wiley, 2017

William Powrie, Soil Mechanics: Concepts and Applications, Spon, 2004

Metodi didattici

Lectures are organised as follows.

Theory: through slides, videos and at the board;

Worked examples: direct application of theory, typically at the board, with students active involvment.

A workshop is delivered on the design of piled foundations for wind turbines by Aligi Foglia of Fraunhofer IWES. 

Modalità di verifica e valutazione dell'apprendimento

The assessment is in two parts (written and oral) as follows. Students should pass the written part to be admitted to the oral part.

Written. Three worked examples (one for each module) are given with free access to books and notes for the solution. Mark weight = 3/4.

Oral. Discussion on the written part and questions on the main topics of the course. Mark weight = 1/4.

The exam dates are set a the end of the course, from 08/06/2020.

Note: half of the the exam (written, two worked example, for module I and for module II) can be also taken at the end of the first cycle (Mark weight = 2/4). Dates are set within the winter exam period, that is from 18/12/2019 to 19/02/2020.

The exam evaluation will be registered not before the end of the course, that is 08/06/2020.

Strumenti a supporto della didattica

slides and blackboard

Orario di ricevimento

Consulta il sito web di Laura Govoni