Abstract #
This paper presents a detailed investigation into the behavior of concrete bored piles, focusing on the shear skin transfer mechanism between the pile and surrounding soil. The study involves in situ testing and numerical modeling using a semi-analytical approach. The research was conducted near the town of Chomutov in the Czech Republic, where infrastructure development required the construction of pile foundations for bridges. The paper details the method used to measure vertical strains at various depths in the instrumented piles, and compares the experimental data with results obtained from numerical simulations performed with GEO4 software.
Technical Relevance #
This document is highly relevant for geotechnical engineers and researchers involved in the design and analysis of deep foundations, particularly those working with bored piles in infrastructure projects. The study provides critical insights into the importance of accurately modeling the pile-soil interface to predict pile behavior, emphasizing the role of shear skin transfer in determining settlement and load distribution.
Target Audience #
The document is intended for geotechnical engineers, civil engineers, researchers, and professionals engaged in foundation design and analysis. It is especially useful for those focusing on the performance of bored piles under various load conditions, as well as those involved in large-scale infrastructure projects such as bridges and highways.
Software and Methodology #
The numerical modeling was carried out using the GEO4 software, which employs a semi-analytical approach to compute settlement and normal force distribution along the pile. The pile-soil interface was modeled using nonlinear soil springs, with shear peak forces limited by the vertical earth pressure and the quality of the interface at each point. The study discretized the pile into cylindrical bar elements, concentrating the interface at nodal points, and applied known analytical solutions to simulate the shear response of the soil layers surrounding the pile.
Process Description #
The paper begins with an overview of the infrastructure project in Chomutov, Czech Republic, where the piles were tested. The process description includes the setup of in situ measurements, which involved instrumenting the piles to measure vertical strains at various depths during loading tests. The measured data were used to calculate the normal force distribution along the pile, and the results were compared with predictions from the numerical model. The study also provides a detailed explanation of the semi-analytical method used for modeling the pile-soil interface and the influence of shear skin transfer on pile behavior.
Main Findings #
The study finds that shear skin transfer has a significant impact on the settlement and axial force distribution of bored piles. The numerical model developed using GEO4 software closely matched the experimental results, demonstrating the importance of accurately modeling the pile-soil interface. The research highlights the need for detailed analysis of the shear zone around the pile, as this directly influences the pile’s load-bearing capacity and settlement behavior. The study also underscores the importance of considering the layered nature of the soil when predicting pile performance.
Practical Applications #
The findings from this study are directly applicable to the design and analysis of bored piles in civil infrastructure projects. Engineers can use the insights gained to improve their numerical models, ensuring that the shear skin transfer and pile-soil interface are accurately represented. This approach is particularly valuable for projects where the performance of deep foundations is critical, such as in the construction of bridges, highways, and other large-scale infrastructure.
Limitations and Considerations #
The document acknowledges that while the numerical model provides a good match with experimental data, the accuracy of the predictions depends on the quality of the input data, particularly the soil parameters and interface properties. Engineers should conduct thorough site investigations and consider local geological conditions when applying these findings to their projects. The study also emphasizes the need for ongoing research to refine the modeling techniques and improve the accuracy of predictions under varying load conditions.
Conclusions #
The paper concludes that the shear skin transfer mechanism plays a crucial role in the behavior of bored piles, and that accurate modeling of the pile-soil interface is essential for predicting settlement and load distribution. The study demonstrates the effectiveness of the semi-analytical approach used in GEO4 software for modeling these interactions, providing valuable guidance for geotechnical engineers involved in deep foundation design. The research suggests that further refinement of the numerical model could enhance its applicability to a wider range of geotechnical conditions.
Related Resources #
Further reading includes studies on the application of shear skin transfer models in geotechnical engineering, as well as research on the use of semi-analytical methods for predicting pile behavior. Additional resources on the calibration of pile-soil interface models and their application in large-scale infrastructure projects can provide deeper insights into optimizing foundation design.
📥 Download LINK
