RSM was initiated in 2013 to optimize operational cost efficiency and minimize potential incidents during jack-up emplacement, particularly due to punch-through failure. In the later stage of RSM, a study was carried out to assess punch-through failure using probabilistic method. This paper presents a probabilistic assessment of punch-through failure in strong overlying weak clay for a Keppel FELS B Class jack-up rig. Using probability density functions, a model was created to calculate the probability of punch-through by comparing the ultimate bearing capacity of strong overlying weak clay with the maximum preload using a limit state function. Monte Carlo simulations were also defined and executed. The probabilities of punchthrough at 100 locations in Malaysian Waters were studied using this approach. The probabilistic approach enables the probability of punch-through in strong overlying weak clay to be quantitatively computed. The resulted probability of punch-through was analyzed using a geostatistical tool and used to predict the risk associated to jack-up emplacement spatially throughout the area of interest. A regional map of probability of punch-through and the associated standard errors is presented in this paper.
Christian H. Girsang, Muhammad J. Rohani, Noorizal N. Huang, Norhayati Yusoff and Azam A. Rahman
Keywords: predictive, jack-up, probability, punch-through, Monte Carlo
Publisher: DFI