振冲系泊桩基础成桩试验研究

目前海上风电以单桩或群桩基础为主,基础依靠深插桩体满足风机结构竖向抗拔承载力要求,随着大功率海上风电机组的投产与安装,如何提高桩基础抗拔承载能力成为制约海上风电大规模发展的瓶颈。本文以改进的振冲器为施工器械,结合预应力锚杆关键技术,综合振冲加固与高压旋喷桩的施工工艺形成了振冲系泊桩成套施工技术,提出了振冲系泊桩新型桩基础;开展了现场成桩试验和现场载荷试验,结果显示:运用该成套技术形成的振冲系泊桩桩身完整性良好且具有较强的抗拔性能;进行了有限元模拟仿真,分析了振冲系泊桩承载机理和破坏模式,通过仿真计算知3.5 m桩长的振冲系泊桩在一般黏土地基中的单桩极限抗拔承载力可达450 kN,是相同桩长的圆柱桩的7.5倍。

Research on forming experiment of vibrating-mooring pile

At present, the foundation of offshore wind power is dominated by single pile or pile group. This kind of foundation mainly depends on inserting deeply to meet the bearing capacity of pile. With the commissioning and installation of high power offshore wind turbines,how to improve the uplift capacity of pile foundations has become a bottleneck. Improvement of vibrator is construction equipment for vibrating-mooring pile. This kind of pile combines with key technology of prestressed anchor,making use of the construction technology of vibrator reinforcement and the high pressure jet grouting pile to formulate construction technology of vibrating-mooring pile. The pile load test and field experiment results show that the vibrating mooring pile has good integrity and better uplift bearing capacity. The finite element method is used to analyses the bearing mechanism and failure mode of vibrating-mooring pile. The ultimate uplift bearing capacity of single vibrating-mooring when the pile length is 3.5m in clay ground is 450kN which is 7.5 times as lerge as that of cylindrical pile with the same length.