In the vast, arid landscapes of Xinjiang, a critical challenge for construction and energy projects has long been the unpredictable behavior of coarse-grained mixed soils when they encounter water. These soils, common in the diluvial areas at the foot of mountains, can suddenly collapse, leading to costly engineering problems. A recent study published in *Yantu gongcheng xuebao* (translated as “Rock and Soil Engineering”) sheds new light on how the fine particles within these soils influence their mechanical properties, offering valuable insights for the energy sector and infrastructure development.
Led by ZHANG Chong of Southwest Jiaotong University, the research team conducted a series of triaxial tests on typical coarse-grained mixed soils from the Turpan area. Their findings reveal that as the content of fine particles increases, the peak stress of these soils decreases, and their stress-strain behavior shifts from strain softening to strain hardening. “This means that soils with higher fine particle content become more stable under load but lose some of their initial strength,” explains ZHANG Chong, the lead author of the study. This discovery could have significant implications for the design and stability of foundations for wind turbines, solar farms, and other energy infrastructure in the region.
The study also found that both the internal friction angle and cohesion of the mixed soil decrease as the fine particle content increases, with cohesion declining at a faster rate. “This suggests that while the soil may become more compact, it also becomes less resistant to shear forces,” says LIU Xianfeng, a co-author from the same institution. This insight is particularly relevant for the energy sector, where understanding soil behavior is crucial for ensuring the long-term stability of large-scale projects.
One of the most intriguing findings was the evolution of bulk strain in the soil samples. The researchers observed that all samples exhibited shear shrinkage followed by shear expansion, with the extent of shear shrinkage increasing with both fine particle content and confining pressure. “This behavior is critical for predicting how soils will react under different loading conditions, such as those imposed by heavy machinery or foundation structures,” notes YUAN Shengyang, another co-author.
The implications of this research extend beyond immediate engineering applications. By providing a clearer understanding of how fine particle content affects soil mechanics, the study offers a foundation for developing more accurate models and guidelines for construction in regions with similar soil conditions. This could lead to more efficient and cost-effective design practices, ultimately benefiting the energy sector by reducing risks and improving project outcomes.
As the energy sector continues to expand into remote and challenging environments, the insights from this study will be invaluable. By leveraging this new understanding of soil behavior, engineers and developers can make more informed decisions, ensuring the stability and longevity of their projects. The research, published in *Yantu gongcheng xuebao*, represents a significant step forward in the field of geotechnical engineering, with far-reaching implications for the future of construction and energy development in Xinjiang and beyond.