In the ever-evolving world of construction and engineering, understanding the behavior of pile foundations under complex loading conditions is crucial, especially for the energy sector where structures often face dynamic and multi-directional forces. A recent study published in ‘Shanghai Jiaotong Daxue xuebao’ (Journal of Shanghai Jiaotong University) sheds new light on this subject, offering insights that could significantly impact the design and safety of offshore wind farms, oil rigs, and other critical energy infrastructure.
The research, led by JIANG Jie and his team from Guangxi University, focuses on the force and deformation of pile foundations under the combined action of horizontal dynamic loads and torque. This is a complex problem that has long puzzled engineers, particularly those involved in the energy sector where structures are often subjected to harsh environmental conditions.
The team, which includes CHEN Lijun, CHAI Wencheng, AI Yonglin, OU Xiaoduo, and GONG Jian, introduced a novel approach by considering the shear effect of soil on the pile side using the Pasternak foundation model. This model, which accounts for both the vertical and horizontal deformations of the soil, provides a more accurate representation of real-world conditions. “By incorporating the Pasternak foundation model, we were able to capture the intricate interactions between the soil and the pile, which is crucial for understanding the overall behavior of the structure,” explains JIANG Jie.
One of the key findings of the study is the introduction of the H(t)-T coupling factor, which reveals the influence mechanism of multi-directional loads on pile response. This factor is particularly important for energy infrastructure, where structures are often subjected to both horizontal and torsional forces. The researchers used the virtual work principle to derive the comprehensive stiffness matrix of the pile element, and then employed a modified finite beam element method to obtain numerical solutions for the internal forces and displacements of the piles.
The results of the study are promising. The researchers found that the soil shear effect can restrain horizontal displacement of the pile, which is a significant finding for the design of offshore structures. Additionally, the study showed that increasing the dimensionless frequency of the dynamic load can reduce the displacement of the pile top and the maximum bending moment of the pile body. This could lead to more efficient and cost-effective designs for energy infrastructure.
The implications of this research are far-reaching. For the energy sector, where the safety and reliability of structures are paramount, this study provides valuable insights that could shape future developments. “Our findings could lead to more robust and efficient designs for offshore wind farms, oil rigs, and other critical energy infrastructure,” says CHAI Wencheng. “By better understanding the behavior of pile foundations under complex loading conditions, we can design structures that are not only safer but also more cost-effective.”
The study also highlights the potential of the modified finite beam element method, which significantly reduces the number of discrete units and computation time. This could lead to more efficient design processes and faster project completion times, which are always highly valued in the energy sector.
The research, published in the Journal of Shanghai Jiaotong University, represents a significant step forward in the field of geotechnical engineering. As the energy sector continues to evolve, with a growing demand for offshore wind farms and other complex structures, the insights provided by this study will be invaluable. The commercial impacts could be substantial, with potential cost savings and improved safety standards that could benefit both developers and end-users alike.