Research on the Influence of Spudcan Penetration and Extraction on Adjacent Platform Piles in Sand

Abstract Jack-up rigs are important equipment for drilling and workover in offshore oil and gas fields. Their operation site is often close to long-running jacket platforms. Spudcan penetration and extraction may have a significant influence on the lateral bearing capacity of adjacent piles of platforms. In this study, centrifuge model tests for the lateral bearing capacity of piles in sand were performed, in which model piles included an isolated pile and two spudcan-affected adjacent piles. Based on the test results of the isolated pile, the lateral soil resistance–displacement (p–y) curve for an isolated pile in sand was modified. By making a comparison of the test results of the three piles, the influence of spudcan penetration and extraction on lateral bearing capacities, bending moments, and the soil resistance of adjacent piles was analyzed. The analysis showed that the lateral bearing capacity of an adjacent pile had 8.9% reduction compared with that of an isolated pile. According to the modified p–y curve of isolated piles, a p–y curve model for a pile affected by spudcan penetration and extraction was proposed by introducing the attenuation coefficient of the sand strength. It provides an option for calculating the lateral bearing capacity of adjacent piles affected by spudcan penetration and extraction in the field of engineering.