大直径桩身开孔单桩在海上风电中的应用

Application of Large-diameter Hole-opening Pile in Offshore Wind Power Project

海上风电长距离溜桩工况下,桩内气体短时间内急剧压缩将液压锤顶起,使得桩、锤脱离,可能造成船机设备损坏的险情,需要采取有效的溜桩保护措施。通过技术研究和创新,采取桩身开孔和桩帽开孔改造措施,及时排出桩内气体,避免了沉桩船机设备受损;桩内气体与外界大气连通,降低了密闭空间作业风险,条件允许时可免去沉桩完成后需要桩内吸水及撒石灰的施工工序。推导出的桩身开孔尺寸计算公式,适用于不同直径的钢管桩桩身开孔设计,可为其他存在软弱地质夹层的海上风电项目的溜桩保护提供参考。

Under the condition of long-distance pile sliding in offshore wind power project,the air in the pile is compressed rapidly in a short period of time to lift up the hydraulic hammer,separate the hammer from the pile,which may damage the equipment mounted on the ship,thus effective measures are required to avoid pile sliding.Technical research and innovation lead to such measures as hole-opening on pile body and pile cap,which supports the discharge of the gas in the pile in time and protects the equipment on pile-sinking ship.The air in the pile connects to atmosphere,which lowers the risk of operation in a confined space.After the pile is sunk,the construction process of water absorption and lime spreading in the pile can be simplified subject to actual situation.The deduced formula for calculating hole-opening size of pile body can be applied in the hole-opening design of steel pipe piles in different diameters,which will provide a reference for the protection of sliding pile in other offshore wind power projects based on weak geological inter-layers.