Impact-driven pipe piles are commonly used in offshore structures, but vibratory driving is becoming more popular due to advantages regarding noise emissions, material fatigue and installation time. In offshore practice, crane-guided vibratory driving is used for maximum control over the installation process. Regarding the load-bearing behaviour of piles, the influence of the installation method is currently subject to research. To contribute to this question, comparative scale model investigations were carried out on impact-driven, jacked and vibratory-driven piles in dense sand. The tests focused on variations of vibratory installation parameters, including crane-guided and free vibratory driving. Based on measurements at the pile and in the soil, the influence of dynamic pile motions on the soil stress development could be analysed. The well-known increase of radial effective soil stresses due to impact driving could be reproduced. The tests showed that the same effects could be evoked by free vibratory driving if certain vibration parameters were met. Increased soil stresses may be beneficial for the lateral or axial pile behaviour, but can cause problems regarding drivability. A sequential application of crane-guided and free vibratory driving may optimise both the installation process and the bearing behaviour.

中文翻译：

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砂土中管桩不同安装方法的应力影响

冲击驱动管桩通常用于海上结构，但由于噪声排放、材料疲劳和安装时间方面的优势，振动驱动变得越来越流行。在海上实践中，起重机引导振动驱动用于最大限度地控制安装过程。对于桩的承载性能，目前正在研究安装方法的影响。为了解决这个问题，对密砂中的冲击桩、顶压桩和振动桩进行了比例模型研究。测试的重点是振动安装参数的变化，包括起重机引导和自由振动驱动。根据桩和土中的测量，可以分析动态桩运动对土应力发展的影响。可以再现众所周知的由于冲击驱动而导致的径向有效土壤应力的增加。测试表明，如果满足某些振动参数，自由振动驱动也可以产生相同的效果。增加的土壤应力可能有利于桩的横向或轴向行为，但可能会导致驾驶性问题。起重机引导和自由振动驱动的顺序应用可以优化安装过程和轴承性能。