基于GRLWEAP的桩基可打性分析方法评价及参数优化

Analysis on the Method of Evaluation and Parameter Optimization of Pile Foundation Drivability Based on GRLWEAP

桩基础在海上风电工程中得到广泛应用,在地质条件复杂的福建海域,沉桩作业面临着沉桩不到位及卷边等风险,桩基可打性分析在沉桩施工及桩长设计中具有重要的指导与参考意义。GRLWEAP软件在可打性分析计算中提供了多种土层分析方法。本文结合福建地区海上风电工程实际沉桩情况,针对国内常用的美国石油协会标准(American Petroleum Institute,API)与标准贯入试验N值(Standard Penetration Test N-Values,SA)分析方法进行计算验证。计算结果表明,API相较于SA分析方法在该地区更接近实际情况。进一步对API分析方法中土层侧阻参数进行优化,在覆盖层与基岩层侧阻值中分别引入折减系数0.8和扩大系数1.5,并对优化后的模型进行验证。验证结果表明,参数优化后的模型在福建地区特殊地质条件下桩基可打性分析中更具参考意义。

Pile foundation is widely used in offshore wind engineering. In the sea area off Fujian Province with complex geological conditions, pile sinking is faced with risks such as inadequate pile sinking and curling. The analysis of pile drivability has important guidance and reference significance in pile sinking construction and pile length design. GRLWEAP provides a variety of soil layer analyzing methods in the analysis and calculation of drivability. Combined with the actual pile sinking situation of offshore wind projects in the Fujian area, the calculation and verification are carried out according to the commonly used API(American Petroleum Institute) and SA(Standard Penetration Test N-Values) analysis methods in China. The results show that the API method is closer to the actual situation in this area compared with SA. Furthermore, the parameters of soil layer side resistance in API analysis method are optimized, and the reduction coefficient 0.8, the expansion coefficient 1.5 are introduced into the side resistance value of overburden layer and bedrock layer respectively, and the optimized model is verified. The verification results show that the model after parameter optimization has more reference significance in the analysis of pile foundation drivability under special geological conditions in the Fujian area.