筒型桩靴在饱和砂土中的贯入阻力研究

桩靴贯入阻力的准确预测是自升式钻井平台安全作业的前提。通过小比尺模型试验,研究饱和砂土中桩靴贯入速度对筒型桩靴插桩性能的影响,并基于地基承载力理论提出筒型桩靴贯入阻力的计算方法,进而采用CEL有限元方法模拟筒型桩靴的贯入过程,并与试验结果进行比较。研究发现:当模型试验中桩靴贯入速度在0.1～0.3mm/s时,桩靴的贯入可看作是准静态过程,此时贯入阻力变化不大,采用基于地基承载力理论中的Hansen公式和Vesic公式可较为准确地计算出对应某一深度的贯入阻力;CEL有限元方法可有效模拟筒型桩靴的贯入过程,当桩靴的贯入速度为0.1～0.3mm/s时,数值模拟结果与试验结果吻合较好。

Bucket Spudcan Penetration Resistance in Saturated Sand

The accurate prediction of spudcan penetration resistance plays an important role in the safety of work on Jack-up drilling platforms. In this work, by carrying out small-scale model tests, the influence of penetration speed on the pile-penetration performance of bucket spudcans in saturated sand was studied, and a computational formula for calculating the bucket spudcan penetration resistance was developed based on the bearing capacity of the ground. Subsequently, the penetration process of the bucket spudcan was simulated by the coupled Eulerian-Lagrangian (CEL) finite element method, and the results were compared with test results. The investigation results showed that, when the penetration speed of the spudcan is 0.1~0.3 mm/s in the model test, the penetration process of the bucket spudcan can be regarded as a quasi-static process, and the penetration resistance varies little. The penetration resistance of the bucket spudcan at a certain depth can be calculated accurately by using the Hansen and Vesic formulas. The CEL finite element method can simulate the bucket spudcan penetration process exactly, and the simulation results were in good agreement with the test results when the penetration speed of the spudcan was 0.1~0.3 mm/s.