海上风电大直径单桩嵌岩施工的溜桩分析及对策

Analysis and countermeasures on pile sliding for large-diameter single-pile rock-socketed construction of offshore wind power

嵌岩施工中溜桩的根本原因是桩侧阻力与端阻力之和小于桩锤体系重量,导致了施工中的溜桩现象。嵌岩施工时桩内钻孔之后使桩的受力状态发生了改变,桩内侧土体掏空使桩内侧阻力消失,桩前端土体掏空使桩端阻力下降,此外钻孔后塌孔还会导致桩外侧土体随之坍落,造成桩外侧阻力降低。从海上风电大直径单桩嵌岩施工的溜桩机理研究出发,分析嵌岩施工的溜桩影响因素,对某海上风电项目的嵌岩施工的溜桩问题进行深入分析研究,提出了嵌岩施工溜桩问题的应对方法。研究成果可为今后海上风电大直径单桩嵌岩施工提供技术支撑。

The direct cause of pile sliding is that the sum of pile side resistance and end resistance is less than the weight of pile hammer system,which leads to the phenomenon of pile sliding during the rock socketed construction.The stress state of the pile will be changed after the drilling in the pile during rock socketed construction,the hollowing of the soil inside the pile makes the inner friction resistance disappear,and the hollowing of the soil below the pile bottom makes the tip resistance of the pile decrease.In addition,the instability of drill hole after drilling will also lead to the collapse of the soil outside the pile,resulting in the reduction of the external friction of the pile.Starting from the research on the pile sliding mechanism of largediameter single-pile rock-socketed construction of offshore wind power,the influencing factors of the pile sliding in the rocksocketed construction were analyzed.The method to deal with the problem of slipping piles in rock-socketed construction was presented.The research results can provide technical support for the construction of large-diameter single pile rock-socketed in offshore wind power in the future.