Stability control of roadway surrounding rocks under repeated mining: a case study

Area of Science:

• Mining Engineering
• Geotechnical Engineering
• Rock Mechanics

Background:

• Repeated mining complicates roadway surrounding rock deformation and failure compared to single-seam conditions.
• Large deformation and support failure in roadways pose significant challenges in mining operations.

Purpose of the Study:

• To analyze the evolution of stress, displacement, and plastic failure in roadways under different seam spacings and mining stages.
• To investigate the factors influencing floor failure depth, including geometric and material properties.
• To develop and validate optimized support schemes for roadways experiencing complex stress conditions.

Main Methods:

• Combined theoretical calculations and numerical simulations to model roadway behavior.
• Analyzed the impact of seam spacing, mining stages, and geological parameters (included angle, internal friction angle, elevation) on failure depth.
• Validated simulation results through field verification and implemented optimized support systems.

Main Results:

• Floor failure depth is significantly influenced by the synergistic effects of included angle, internal friction angle, and elevation.
• Reduced interlayer spacing intensifies roadway deformation, leading to increased roof displacement and peak horizontal stress.
• Optimized support schemes ('5-4-5' roof and '3-4-3' side cables; asymmetric support) effectively limited convergence and displacement.

Conclusions:

• The study provides crucial theoretical guidance for stability control and support optimization in roadways subjected to complex mining stresses.
• Effective support strategies are essential for mitigating large deformations and ensuring roadway stability in multi-seam mining environments.
• Understanding the interplay of geological factors and mining-induced stresses is key to designing robust support systems.