Effect of water jetting on soil properties and spud-can penetration/extraction in various soil conditions: numerical simulation vs. physical model test

Abstract

ABSTRACTSpud-cans are used for fixing jack-up rigs on seabed. The spud-can needs to be inserted up to the required depth during the installation process in sand to secure enough soil resistance and prevent overturning accidents. In the clay case, its penetration depth is much larger and it typically takes long time to extract it from the large burial depth. In both cases, water jetting is needed to make it possible or expedite the process. To achieve such goals, spud-can may be equipped with water-jetting system including monitoring and control. In this regard, authors developed a numerical simulation tool by using a commercial FE (finite element) program ANSYS and the extended Drucker–Prager (EDP) equation involving water-jetting effect. Authors also conducted small-scale (1/100) physical model tests to validate the developed analytical/numerical model. By comparing the numerical model against experiment, essential physics are drawn with calibrated soil properties including the effects of water jetting. Then, by using the tuned soil properties, the numerical simulations reproduced the essential characteristics and behaviours of the model tests with sand and K(kaolin)-clay. Finally, for further verification, the cases of sand/K-clay multi-layer with and without water jetting are cross-checked against experimental results to show reasonably good agreement.