Deformation and Fracture Behavior of Argillaceous Weakly Cemented Rock Under Hydromechanical Interaction: Experimental Study and UDEC‐Trigon Simulation

This study investigates innovative methods to address the stability issues of roadways with argillaceous weakly cemented surrounding rock (AWCR) in western China′s coal mining regions. The research focuses on the hydromechanical properties of AWCR, analyzing its mineral composition, pore structure, and microstructure, which reveal high porosity and poor cementation integrity. Under hydromechanical interactions, AWCR exhibits significant strength degradation and deformation, with the peak and residual strengths decreasing as moisture content increases. Laboratory tests quantified the degradation of strength and deformation parameters with increasing moisture content. A constitutive model for AWCR under hydromechanical coupling was developed and implemented in the UDEC. Numerical simulations using this model successfully replicated the triaxial test responses and, more importantly, revealed the progressive failure process of roadways in AWCR strata, which is characterized by initial shear cracking at roof shoulders followed by tensile crack propagation and coalescence. Based on these failure mechanisms, a combined control technology was proposed, comprising full‐section shotcreting for sealing, zonal (deep and shallow) grouting for reinforcement, and a high‐prestress bolting/cabling system for active support. Field application in Dananhu No. 5 Mine demonstrated the effectiveness of this approach, with monitoring data showing controlled deformation and stable support loads. The findings provide a theoretical framework and practical solutions for ensuring roadway stability in weakly cemented formations.