Bearing capacity of spudcan foundations in a spatially varying clayey seabed

Abstract

A B S T R A C TSpudcan foundations are often pushed into a spatially varying non-homogeneous seabed to provide bearing capacity for a mobile jack-up platform. The natural variability of soil properties coupled with the complexity of loading conditions make determining the bearing capacity of spudcan foundations a challenging problem. A random finite element method is established to investigate the bearing capacity of a spudcan foundation embedded in a spatially varying clayey seabed when subjected to vertical, horizontal and moment loadings. A criterion is proposed for determining the characteristic value of the shear strength for the random seabed. Results indicate that the spatial variability in the clayey seabed significantly reduces the bearing capacity of a spudcan foundation. This reduction is more significant in the vertical bearing capacity than in the horizontal and moment bearing capacities. The mean bearing capacity is smaller for the clay with larger coefficient of variation of undrained shear strength. A characteristic value of mean minus a standard deviation of the undrained shear strength is capable to ensure the probability of failure is not greater than 5%. This study provide an evaluation method for the spatial variability effect of a clayey seabed, paving the way for a costeffective design of spudcan foundations.

Reliability-based evaluation of ultimate embedment depths of torpedo anchors in spatially variable clay

“…It has been reported that the horizontal autocorrelation length of marine soil is two orders of magnitude larger than its vertical corresponding length; among which and are between 0.05~14m and 7~9000m [14], respectively, which may be caused by the geological deposition process. The horizontal and vertical correlation lengths for this paper are taken as 50.7m and 3.8m [6,13,14]. However, the diameter of the torpedo anchor is very small relative to the and the range of the mobilized soil during the installation of the anchor is extremely limited in the horizontal direction.…”

“…The coefficient of variation (COV)su and the autocorrelation length (θ) are two statistical metrics that quantify the random heterogeneity that is reflected in the random residual. According to research [7,14], the COVsu of clayey soil typically ranges from 0.02 to 0.7. It has been reported that the horizontal autocorrelation length of marine soil is two orders of magnitude larger than its vertical corresponding length; among which and are between 0.05~14m and 7~9000m [14], respectively, which may be caused by the geological deposition process.…”

“…According to research [7,14], the COVsu of clayey soil typically ranges from 0.02 to 0.7. It has been reported that the horizontal autocorrelation length of marine soil is two orders of magnitude larger than its vertical corresponding length; among which and are between 0.05~14m and 7~9000m [14], respectively, which may be caused by the geological deposition process. The horizontal and vertical correlation lengths for this paper are taken as 50.7m and 3.8m [6,13,14].…”

Optimization for the Assessment of Spudcan Peak Resistance in Clay–Sand–Clay Deposits

“…Probabilistic methods provide a feasible way to perform real-time optimization for the prediction based on the monitored data. The percentile curves or probabilistic contours of the spudcan load-penetration response can be predicted through Monte Carlo simulations by account-ing for the uncertainties and probabilistic distribution of the inputs in the predictive model [11,[13][14][15]. Bayes' theorem can then be adopted to update these predictions according to the measured load-penetration data [16,17].…”

Wind Turbine Airfoil Boundary Layer Optimization Using Genetic Algorithm with 3D Rotational Augmentation

“…The wind farm layout optimization is reviewed by Serrano González [5]. Mostly objective functions are the minimization of cost of energy, maximization of the power production, minimization of the blade mass, and so on [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The geometrical, aerodynamic, and physical aspects are to be researched when the constraints are in the field of turbine design.…”