In the high-stakes world of energy infrastructure, the reliability and efficiency of deeply buried pressure pipelines are paramount. A groundbreaking study led by Liu Yijie, published in the journal *Engineering Sciences and Technology* (工程科学与技术), delves into the intricate load-bearing mechanisms of these pipelines under high internal water pressure, offering insights that could revolutionize engineering design and construction practices.
The research focuses on the interplay between the steel lining, concrete layer, and surrounding rock, providing a detailed analysis of how these components interact under varying conditions. “The core of this approach lies in determining the potential functions for the steel lining and surrounding rock layers, as well as the contact stresses between each structural layer,” explains Liu Yijie. This method allows for the accurate calculation of stress and deformation fields, which are crucial for predicting the performance and longevity of these pipelines.
One of the most significant findings is the impact of internal water pressure on the radial expansion of the pipeline. As the pressure increases, the steel lining expands, and the external concrete layer and surrounding rock bear a substantial portion of the load. This insight could lead to more cost-effective designs, as Liu Yijie notes, “If the surrounding rock is structurally sound and stable, and the quality of concrete filling can be assured, the thickness of the steel lining may be appropriately reduced to optimize construction costs.”
However, the study also highlights the critical role of the concrete layer. When cracks develop in the concrete, the load-bearing capacity is compromised, and the internal water pressure is redistributed between the steel lining and the surrounding rock. This redistribution can lead to increased stress and deformation in both components, with the steel lining assuming a larger share of the load. “The extent of this shift depends on the overall structural parameters and the magnitude of the applied internal water pressure,” Liu Yijie explains.
The research also underscores the importance of the interlayer gap between the steel lining and the concrete layer. Even minor gaps can significantly affect the load transfer and distribution within the composite system. For instance, the study found that the surrounding rock’s load-sharing ratio decreased from 71.31% under zero-gap conditions to 44.35% when the gap reached 1 mm. This finding could have profound implications for the design and construction of future pipelines, emphasizing the need for precise engineering and quality control.
Moreover, the classification of the surrounding rock plays a substantial role in the load-sharing ratio. The study found that the difference in circumferential tensile stress in the steel lining between Class II and Class V surrounding rock conditions reached 40.93 MPa, with a corresponding difference of 20.56% in the surrounding rock’s load-sharing ratio. When concrete cracking was considered, these differences became even more pronounced, highlighting the need for reinforcement measures such as grouting to enhance the surrounding rock’s contribution.
The implications of this research for the energy sector are vast. By providing a deeper understanding of the load-bearing mechanisms of deeply buried pressure pipelines, this study offers a framework for more accurate and efficient engineering designs. It also underscores the importance of quality control and precise engineering in the construction of these critical infrastructure components.
As the energy sector continues to evolve, the insights gleaned from this research will be invaluable in shaping future developments. By optimizing the design and construction of deeply buried pressure pipelines, we can enhance the reliability and efficiency of our energy infrastructure, ensuring a more sustainable and secure energy future.