# A Numerical Analysis on Lateral Resistance of Pile-Bucket Foundation for Offshore Wind Turbines
## 6 Conclusions  
In this paper, the finite element analysis model of P-BF with different pile diameter/bucket diameter combinations was established in ABAQUS to analyze the effect of a tube on the lateral bearing performance of a large-diameter single pile. The results demonstrate that in P-BF, the bucket mainly provides lateral bearing resistance and the pile mainly provides an anti-overturning moment. Compared with the height of the bucket, the diameter of the bucket has a greater effect on the lateral bearing resistance of the pile-bucket foundation. In particular, based on the results of the finite element simulation, the API specification recommends a monopile revised _p-y_ curve, which is obtained and which is suitable for the composite foundation level load performance of the pile _p-y_ curve.  
The conclusions are as follows:  
1. The internal force distribution of P-BF is consistent with the rule of PF. The reinforcement effect of the bucket on the pile body is significant. In order to enhance the bearing capacity of P-BF, it is more effective to increase the diameter of the bucket body at the same magnitude.
2. Within the reinforced range of the bucket, the lateral ultimate soil reaction of the P-BF at the same depth is much larger than that of the PF. The eigenvalue \(y_{50}\) of the pile displacement varies linearly with depth.
3. The height of P-BF with the same diameter has a greater influence on the _p-y_ curve than that of the shallow layer, and increasing the height of the pile-bucket reduces the \(P_{ult}\) value to a certain extent. Due to the fact that the increase in bucket height does not improve the bearing capacity of P-BF, we conclude that when the pile diameter is greater than 6 m, increasing the bucket height can make the reinforced section of the foundation bear more uniform load on the basis of a constant bucket diameter.
4. In the P-BF, the reinforcement section of the bucket is the main contribution to the lateral bearing capacity of the foundation, which provides more than 90% of the bearing capacity. At the same time, the unreinforced section in the pile provides enough anti-overturning capacity for the foundation, which significantly improves the overall lateral bearing capacity of the foundation.
5. The distribution of the _p-y_ curve of the P-BF is similar to that of PF. The _p-y_ curve of PF recommended by API and the _p-y_ curve of the finite element simulation of P-BF are typical power function distributions. However, when it is extended to P-BF, the key parameters need to be revised, and the revised methods and ideas proposed in this paper can be referred to.  
Conceptualization, Z.Y.; methodology, Z.Y. and X.P.; software, X.W. and J.W.; validation, X.P. and J.Z.; formal analysis, Z.Y. and B.H.; investigation, K.Z.; resources, B.H.; data curation, J.W.; writing--original draft preparation, K.Z. and X.W.; writing--review and editing, K.Z., J.Z. and S.X.; visualization, B.H.; supervision, X.P.; project administration, Z.Y.; funding acquisition, X.W. All authors have read and agreed to the published version of the manuscript.  
This research was funded by National Natural Science Foundation of China grant number [51909249].  
The study did not require ethical approval.  
The study did not involve humans.  
No data were used to support this study.  
The authors declare no conflict of interest.