Numéro : 2242 - Year : 1994
Requalification of damaged offshore platforms
P. BESSE, Direction Technologie Océanique, BUREAU VERITAS
A. MAROINI, Direction Technologie Océanique, BUREAU VERITAS
The aim of this contribution is to propose a methodology which allows to numerically quantify the necessary decision elements for a requalification strategy of damaged platforms. This methodology involves bath deterministic and probabilistic analysis of structural redundancy under extreme environmental conditions.
For the deterministic approach, a computer program which performs non-linear analysis of a structure under push-over loads, and which evaluates its reserve strength, is used The probabilistic approach implements a reliability computer program which calculates the probability of global failure of a structure (modelled as a serial system of paritialallel subsystems) and allows its redundancy analysis. This reliability computer program also includes a pre-processor the propose of which is the calculation of a stochastic modelling of environmental Loads.
The adopted criterion for requalification is based on the (probabilistic) redundancy levels of the structure in its initial
and modified states. The decision-making should also take into consideration the deterministic redundancy level
This requalification technique is illustrated by its application on a real structure ; several damage states are simulated for which the decisions for requalification or not are discussed