In the heart of Beijing and Madrid, a groundbreaking study is redefining how we understand the behavior of rock-socketed piles, with implications that could revolutionize the energy sector’s approach to foundation engineering. Xiaolin Zhao, a leading researcher from Beijing Jiaotong University and the Universidad Complutense de Madrid, has developed a novel analytical approach to estimate the influence of rock fragmentation on the shear behavior of concrete-rock interfaces. This work, published in Case Studies in Construction Materials, promises to enhance the design and safety of deep foundations, particularly in the challenging environments often encountered in energy projects.
Rock-socketed piles (RSPs) are critical components in the construction of offshore wind farms, hydroelectric dams, and other energy infrastructure. These piles transfer loads from structures to the bedrock, but their effectiveness depends heavily on the friction between the pile and the rock, known as pile side friction (PSF). Understanding and predicting this friction is crucial for ensuring the stability and longevity of these structures.
Zhao’s research begins by idealizing the pile-rock interface as a regular triangular asperity, a simplification that allows for a detailed analysis of the shear mechanism. “By modeling the interface in this way, we can better understand how the rock’s fragmented state affects the overall shear behavior,” Zhao explains. This approach led to the development of a shear model for concrete-regular triangular rock (CRTR) under constant normal stiffness, a condition that mimics real-world scenarios.
One of the most innovative aspects of Zhao’s work is the use of the Weibull distribution and statistical theory to establish an evolutionary equation for the rock fragmented variable (RFV). This equation describes how the rock’s fragmented state changes over time and under different conditions. “The RFV is a dynamic parameter that evolves with the shear process,” Zhao notes. “By incorporating this into our model, we can more accurately predict the behavior of the concrete-rock interface.”
Building on this, Zhao constructed a shear model for concrete-regular triangular fragmented rock (CRTFR). This model characterizes the variation of the shear stress-shear displacement curve, providing a comprehensive picture of the interface’s behavior from the linear stage to the residual stage. The model’s accuracy was verified through comparisons with experimental results, showing a strong agreement.
The implications of this research for the energy sector are significant. By providing a more accurate model for predicting the shear behavior of concrete-rock interfaces, engineers can design more efficient and safer foundations for energy infrastructure. This could lead to cost savings, improved safety, and increased reliability in projects ranging from offshore wind farms to hydroelectric dams.
Moreover, the model’s parameters have clear physical meanings, making it a practical tool for engineers. “The mathematical expressions for these parameters can be derived theoretically, which means they can be easily applied in real-world scenarios,” Zhao says. Parameter sensitivity analysis further revealed that factors such as initial normal stress, normal stiffness, asperity angle, basic friction angle, residual friction angle, and rock crushing parameters significantly influence the shear response of the concrete-rock interface.
As the energy sector continues to push the boundaries of what’s possible, with projects in increasingly challenging environments, the need for accurate and reliable foundation engineering has never been greater. Zhao’s work, published in Case Studies in Construction Materials, offers a significant step forward in meeting this need. By providing a deeper understanding of the shear behavior of concrete-rock interfaces, this research could shape the future of foundation engineering in the energy sector, leading to more robust, efficient, and safe infrastructure.
