This paper describes and interprets tests on piles driven through glacial tills and chalk at a Baltic Sea windfarm, covering an advance trial campaign and later production piling. The trials involved six instrumented 1·37 m dia. steel open-ended tubes driven in water depths up to 42 m. Three piles were tested statically, with dynamic re-strike tests on paired piles, at 12–15 week ages. Instrumented dynamic driving and re-strike monitoring followed on up to 3·7 m dia. production piles. During driving, the shaft resistances developed at fixed depths below the seabed fell markedly during driving, with particularly sharp reductions occurring in the chalk. Shaft resistances increased markedly after driving and good agreement was seen between long-term capacities interpreted from parallel static and dynamic tests. Analyses employing the sites’ geotechnical profiles show long-term shaft resistances in the chalk that far exceed those indicated by current design recommendations, while newly proposed procedures offer good predictions. The shaft capacities mobilised in the low-plasticity tills also grew significantly over time, within the broad ranges reported for sandy soils. The value of offshore field testing in improving project outcomes and design rules is demonstrated; the approach described may be applied to other difficult seabed conditions.

中文翻译：

---

粉笔和耕作中的海上桩动，静轴向响应的全尺寸观测

本文描述并解释了波罗的海风电场通过冰川耕作和白垩打入的桩的测试，涵盖了先期试验和后来的生产打桩。该试验涉及六种仪器仪表，直径为1·37 m。钢制开口管，可在高达42 m的水深中驱动。静态测试了三个桩，并在12至15周龄时对成对桩进行了动态重击测试。仪表式动态驾驶和重击监控，最大直径为3·7 m。生产桩。在行驶过程中，在行驶过程中，在海床以下固定深度处产生的轴阻力显着下降，其中白垩的减少特别明显。行驶后的轴阻力显着增加，并且从并行静态和动态测试得出的长期能力之间可以看到很好的一致性。使用站点的岩土剖面的分析表明，粉笔中的长期竖井阻力远远超出了当前设计建议所指示的水平，而新提出的程序可以提供良好的预测。随着时间的推移，在低塑性耕作中动员的竖井能力也显着增加，在报道的沙质土壤的广泛范围内。证明了海上现场测试在改善项目成果和设计规则方面的价值；所描述的方法可以应用于其他困难的海底条件。在沙质土壤的报道范围之内。证明了海上现场测试在改善项目成果和设计规则方面的价值；所描述的方法可以应用于其他困难的海底条件。在沙质土壤的报道范围之内。证明了海上现场测试在改善项目成果和设计规则方面的价值；所描述的方法可以应用于其他困难的海底条件。