Investigating the Mechanism of Continuous–Discrete Coupled Destabilization of Roadway-Surrounding Rocks in Weakly Cemented Strata under Varying Levels of Moisture Content
2023
Lihui Sun | Zhixin Jiang | Yaxin Long | Qingfeng He | Haiyang Zhang
This study examines frequent disasters, including large-scale deformation and collapse, caused by underground mining in weakly cemented strata in Western China. The weakly cemented rock&rsquo:s unique characteristics, including low strength and easy disintegration, demonstrate a different damage pattern than that traditionally seen in the central and eastern regions. Using Fast Lagrangian Analysis of Continua-Particle Flow Code (FLAC2D-PFC2D) coupling, we model the strata, focusing on the 3-1 coal seam roadway at Hongqinghe mine. This study investigates the damage&ndash:rupture&ndash:destabilization progression in the peripheral rock under varying levels of moisture content. Our findings indicate that a water content of &omega: = 5.5% is the threshold for roadway damage, and moisture content <:5.5% yields minimal rock deformation. However, moisture content >:5.5% abruptly increases cracks and shifts the rock&rsquo:s force chain, causing significant deformation and affecting the ceiling the most. Moreover, higher levels of moisture content weaken the anchor solid&rsquo:s performance, with two primary failure modes: anchor interface slippage (comprising five stages: elasticity, elasticity&ndash:shear hardening, elasticity&ndash:shear hardening&ndash:decohesion, shear hardening&ndash:decohesion, and decohesion) and shear damage. These insights are vital for improving numerical simulations of underground mining, obtaining a more accurate understanding of mineral pressure disasters in weakly cemented strata mining regions in Western China, and developing a solid foundation for the better control of such strata.
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