Dynamic properties of deep rocks under different seepage gradients: Experimental investigation and theoretical modeling
Year: 2025
Type: article
Abstract: Deep rock engineering projects are frequently conducted in water-rich regions characterized by elevated geo-stress, differential pore water pressure, and frequent dynamic disturbance. Elucidating the dynamic behavior of rocks under hydraulic-mechanical coupling is critical for evaluating the stability of engineering structures. In this study, a modified triaxial split Hopkinson pressure bar (SHPB) system integrated with hydraulic loading technique was utilized to apply simultaneous differential water pressure and confining pressure. Dynamic loading experiments were performed on white sandstone under varying strain rates and hydraulic pressures to simulate three distinct seepage gradients. The results demonstrated that increasing the water pressure difference between the two ends of the specimen accelerated the development of internal fractures, enhancing intrinsic permeability and exacerbating fragmentation. Both dynamic compressive strength and energy consumption exhibited rate dependency. As the seepage gradient increased, the dynamic compressive strength declined, while energy dissipation capacity remained constant. Building on the principles of element combination theory in rheological modeling, a dynamic constitutive model of rocks was developed under coupled pore and confining pressures by incorporating the hydraulic pressure gradient. Assuming a linear correlation between the hydraulic effects and pore water pressure, the mathematical framework of the model was derived and then validated against experimental results. Finally, the influence of seepage flow, quantified through model parameters, was analyzed in detail.
Authors: Zheng Wang, Tenglong Yue, Geli Zhao, Yachen Xie, Bangbiao Wu, Kaiwen Xia
Institutions: Tianjin University, Yalong Hydro (China), Sichuan University
Language: English
Topic: Rock Mechanics and Modeling
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
Awards: G4748307594, G524235088
OpenAlex ID: W4416890175