【24h】

SCALE MODEL INVESTIGATIONS ON VIBRO PILE DRIVING

机译:振动桩驱动的规模模型研究

获取原文

摘要

Monopiles installed by impact driving are the preferred system for the foundation of offshore wind turbines in water depths up to 40 m. The vibration technique as alternative installation method has big advantages regarding piling noise and installation time. Much experience exists for the design and installation of impact driven piles. Within the research project ZykLaMP, the lack of experience concerning vibrated monopiles shall be faced by means of large-scaled model investigations regarding the lateral load-bearing behavior. Therefore, open ended steel pipe piles (L = 2.4 m, D_(pile) = 0.6 m) are installed into dense sand by means of impact and vibratory pile driving and then subjected to cyclic lateral loading. This paper focusses on pile driving predictions and measurements during the installation process. Pile driving post-predictions were carried out based on a simple force equilibrium approach. Model piles were installed using two different vibro hammers with different eccentric moments and one impact hammer. Measurements of strains and accelerations were carried out to investigate dynamic movements during pile driving. Earth pressure transducers were used to investigate the development of soil stresses due to the installation process. Measurements show that even at high acceleration amplitudes a refusal to vibratory driving may occur at a certain penetration depth. Soil stresses in the vicinity of the pile decrease to about 50 % due to vibratory driving which is one reason for the friction fatigue phenomenon. Drivability studies using the force equilibrium model give rough predictions about whether or not a pile can be driven to a certain penetration depth but are quite sensitive to input parameters. For the model tests, post-predictions gave reasonable results.
机译:通过冲击驱动安装的单桩是在水深不超过40 m的海上风力发电机组基础的首选系统。作为替代安装方法的振动技术在打桩噪音和安装时间方面具有很大的优势。在冲击打桩的设计和安装方面有很多经验。在ZykLaMP研究项目中,有关振动单桩的经验不足应通过有关侧向承载行为的大规模模型研究来解决。因此,通过冲击和振动打桩将开口钢管桩(L = 2.4 m,D_(桩)= 0.6 m)安装在稠密的沙子中,然后承受周期性的横向载荷。本文重点介绍安装过程中的打桩预测和测量。基于简单的力平衡方法进行了打桩后预测。使用两个具有不同偏心力矩的振动锤和一个冲击锤来安装模型桩。进行了应变和加速度的测量,以研究打桩期间的动态运动。土压力传感器用于研究由于安装过程而引起的土壤应力的发展。测量表明,即使在高加速度振幅下,在一定的穿透深度处也可能会拒绝振动驱动。由于振动驱动,桩附近的土壤应力降低到约50%,这是摩擦疲劳现象的原因之一。使用力平衡模型的可驱动性研究给出了关于是否可以将桩打入一定的穿透深度但对输入参数相当敏感的粗略预测。对于模型测试,后期预测给出了合理的结果。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号