基于弗雷歇距离的海上沉桩土阻力推荐方法

Method for calculating the soil resistance during offshore pile driving based on Fréchet distance

摘要:

随着海洋平台以及海上风电规模的扩大,桩基可打入性分析的精度越来越受到关注。打桩过程中土阻力的合理评估是提高可打入性分析准确性的前提,而土阻力分析中最重要的是端阻和侧阻折减系数的取值。以11个海上平台的99个打桩记录为数据库,首先,通过打桩记录数据证明弗雷歇距离算法在海上平台桩基打桩记录之间相似度计算的适用性,确定该海域弗雷歇距离的阈值,并对阈值结果的合理性进行验证;其次,通过计算现场打桩记录反算的土阻力与不同折减系数下计算得到的土阻力之间的弗雷歇距离,对该海域的折减系数进行探讨,并给出有土塞和无土塞工况下折减系数的推荐值。研究结果可为桩基可打入性分析中的土阻力的计算提供借鉴。

Abstract:

With the development of offshore platforms and offshore wind power, the accuracy of pile foundation drivability analysis, which is greatly impacted by soil resistance to driving (SRD), has attracted more and more attention. In SRD analysis, the key is determining the reduction coefficients for end-bearing resistance and shaft resistance. Based on a database that includes 99 pile driving records from 11 offshore platforms, the applicability of the Fréchet distance algorithm in evaluating the similarity between pile driving records was verified, and the threshold of Fréchet distance in the sea area was determined and verified. Then, the Fréchet distance between the calculated SRDs under different reduction coefficients and SRD from the back analysis of pile driving records was calculated, and the recommended values of reduction coefficient were proposed in the cases of soil plug and no soil plug. The results of this study could be helpful for the calculation of SRD in pile drivability analysis.