Environmental Engineering Reference
In-Depth Information
Chapter 7
Structural Analysis of Oil-Spill Booms
Frédéric Muttin
Abstract
Floating barriers, often named booms, are used to contain oil. They are
a main device installed during pollution response and their efficient positioning is
a critical question for both effective oil containment and structural material resis-
tance. A 3D non-linear finite element model for static moored booms is forced by
sea current hydrodynamic pressure. To improve the numerical convergence of the
membrane equilibrium during the Newton-Raphson scheme we initialize the 3D
solution by using a 2D non-linear cable model. The membrane stretched surface rep-
resenting the boom permits to define the material stress and the boom subsea skirt
angulation. Full-scale experiments are performed on the European Atlantic coast to
measure boom mooring tension and boom skirt geometry. In this chapter,
in-situ
experimental method at coastal sea is given. Validation protocol of numerical results
by experimental ones is described. Threshold values on boom tension, to avoid struc-
tural break, and skirt angle to evaluate the oil containment efficiency are discussed.
Finally, methodological aspect to combat oil pollution by using contingency planning
based on such numerical modelling of booming structure is addressed.
7.1 Introduction
Oil-spills at large medium or small scales are a main challenge for response
preparedness. First challenge for intervention is to contain the oil on the sea sur-
face so that the pollutant can be recovered. When oil containment fails, the risk is
that the pollutant enters in contact with the shore giving a polluted material weight
multiplied by a ratio generally known to be 10. This ratio was observed during Erika
tanker crisis [
16
].
The purpose of this chapter is to study a mechanical device named boom which
constitutes a floating barrier against oil drift. Such response material can be used to
contain the oil when the sea current is small and under 0.35m/s. When the current
Search WWH ::
Custom Search