In the heart of underground engineering, where stability is paramount and failure can be catastrophic, a groundbreaking study led by CHEN Yian has shed new light on the behavior of jointed sandstone under shear stress. The research, published in the Journal of Engineering Science and Technology, delves into the mesoscopic failure and acoustic emission characteristics of sandstone, offering insights that could revolutionize how we approach rock stability in the energy sector.
Imagine the intricate dance of forces beneath our feet, where the stability of underground structures hinges on the behavior of rocks under stress. CHEN Yian and his team have developed a novel method to evaluate the fracture mode of rock, using a self-developed rock meso-shear test device and acoustic emission monitoring. This device, equipped with a loading system and a crack meso-observation system, allows for a detailed examination of the shear mechanical behavior and acoustic emission characteristics of jointed sandstone.
The study reveals that the shear stress-displacement curves of sandstone specimens can be divided into five distinct stages, each with unique mechanical properties and acoustic emission characteristics. High-amplitude acoustic emission events, primarily occurring near failure, provide a window into the internal dynamics of the rock. “The morphology of the main crack and the presence of wing cracks are the primary differences in the failure modes of specimens with various joint angles,” CHEN Yian explains. This finding underscores the importance of understanding the joint angle’s influence on rock fracture behavior.
The research also highlights the role of normal stress in altering the fracture mode of sandstone. When normal stress is applied, the main crack morphology becomes vertical, increasing the occurrence of tensile failure. This shift in fracture mode has significant implications for the energy sector, where the stability of underground structures is crucial for the safe extraction of resources.
The study’s findings suggest that as the joint angle increases, the energy distribution between tensile and shear failures changes. When the joint angle aligns with the shear direction, the number of tensile fractures becomes more pronounced, but the rock still undergoes shear fractures. This transition from shear failure to tensile failure provides a theoretical basis for rock stability analysis in underground engineering design.
The implications of this research are vast, particularly for the energy sector. Understanding the fracture mechanisms of jointed rocks can enhance the stability of underground structures, reduce the risk of landslides and pillar instability, and improve the efficiency of resource extraction. As CHEN Yian notes, “By analyzing the shear fracture behavior of jointed rock under different joint angles and normal stresses, the significant influence of these factors on the fracture mode of the rock is revealed.”
This research, published in the Journal of Engineering Science and Technology, marks a significant step forward in the field of rock mechanics. As we continue to explore deeper and more complex underground environments, the insights gained from this study will be invaluable in ensuring the safety and efficiency of our engineering projects. The future of underground engineering lies in our ability to understand and predict the behavior of rocks under stress, and CHEN Yian’s work brings us one step closer to that goal.
