Summary
Objective
The original project objectives are to: (1) determine the currently available best practices for analysis and design of suction caisson anchors (SCA’s) and vertically loaded anchors (VLA’s) including drag embedment anchors, and (2) effect improvements in the installation and capacity predictions for SCA’s and VLA’s.
Approach
Analytical and numerical methods are being developed to predict: (1) the load capacity of suction caissons under general conditions of inclined loading, and (2) the installation trajectory and load capacity of vertically loaded drag embedment anchors. The techniques being developed are based on plastic limit analyses, with finite element analyses being used in the development and validation of the plastic limit formulations. The rationale for using the plastic limit formulation is that it can be implemented in a relatively simple spreadsheet or personal computer format, while maintaining a fairly high degree of theoretical rigor. Thus, plastic limit formulations provide a convenient framework for developing design tools accessible to practitioners
Deployment of Results
The formulation, validation, and parametric studies associated with the analytical and numerical models developed in this project will be presented in offshore technology conferences and peer-reviewed journals. Spreadsheet programs for predicting load capacity of suction caisson and vertically loaded plate anchors are being made available to practicing engineers.
Related Publications
Andersen, K.H., Murff, J.D. Randolph, M.F., Clukey, E., Jostad, H.P., Hansen, B. Aubeny, C., Sharma, P., Erbich, C., and Supachawarote, C. (2005) “Suction anchors for deepwater applications,” Keynote lecture International Symposium on Frontiers in Offshore Geotechnics, Perth, Australia, September 2005, pp. 3-30.
Anderson, K.H., Murff, J.D., and Randolph, M. (2004) Deepwater Anchor Design Practice, Final Year Report submitted to the American Petroleum Institute and the Deepstar JIP.
Aubeny, C.P, Kim, B.M, and Murff, J.D. (2005) “Proposed upper bound analysis for drag embedment anchors, International Symposium on Frontiers in Offshore Geotechnics, Perth, Australia, pp. 179-184.
Aubeny, C.P. and Murff, J.D. (2004) “Simplified limit solutions for undrained capacity of suction anchors,” to be published in Journal of Ocean Engineering.
Aubeny, C.P., Han, S.W.*, and Murff, J.D. (2003a) “Inclined load capacity of suction caisson anchors,” Intl. J. for Numerical and Analytical Methods in Geomechanics, Vol. 27, pp. 1235-1254.
Aubeny, C.P., Han, S.W. and Murff, J.D. (2003b) “Refined model for inclined load capacity of suction caissons,” 22nd International Conference on Offshore and Arctic Engineering, June 8-13, Cancun, Mexico, OMAE2003-37502.
Aubeny C.P. Han S.W.*,and Murff, J.D. (2003c) “Suction caisson capacity in anisotropic soil,” Intl. J. of Geomechanics, Vol. 3, No. 4, pp. 225-235.
Aubeny, C.P., Moon, S.K.*, and Murff, J.D. (2001) “Lateral undrained resistance of suction caisson anchors,” Intl. J. Offshore and Polar Engineering, Volume 11, No. 3, pp. 211-219.
Clukey, E.C., Aubeny, C.P. and Murff, J.D. (2003) “Comparison of analytical and centrifuge model tests for suction caissons subjected to combined loads,” 22nd International Conference on Offshore and Arctic Engineering, June 8-13, Cancun, Mexico, OMAE2003-37503.
Kim, B.Y. (2005) Upper Bound Analysis for Drag Anchors in Soft Clay, PhD Dissertation, Texas A&M University, College Station, Texas.
Murff, J.D., Randolph, M.F., Elkhatib, S., Kolk, H.J., Ruinen, R., Strom, P.J., and Thorne, C. (2005) “Vertically loaded plate anchors for deepwater applications,” Keynote lecture International Symposium on Frontiers in Offshore Geotechnics, Perth, Australia, pp. 31-48.
