Abstract: In the pile foundation construction for offshore oil platform, pile drilling becomes difficult after hammer stops and even repelling of hammering occurs. To explore efficient approach of pile construction, we present a technical proposal of driving pile by high-pressure water jet, and design apparatus for model test. Forces generated by jets with six different nozzles acting on the soil plug are tested, and the stress distributions in the soil are numerically simulated. The maximum and minimum stresses in the soil plug under jet forces are obtained, and model test results are verified. Results showed that it is feasible to improve pile construction efficiency by employing high pressure water jet. Among the six different nozzles, nozzle with iso-variable velocity could generate the longest limited jet distance and in the meantime the largest force on the soil plug surface center. This research provides basis for the preparation of model machine.

Key words: offshore platform, high pressure water jet, assistant pile driving, model test, numerical simulation