To explore the influence of abandoned roadways on the technology of gob side entry retaining formed by roof cutting and pressure release, theoretical analyses, numerical simulations, and field engineering experiments… Click to show full abstract
To explore the influence of abandoned roadways on the technology of gob side entry retaining formed by roof cutting and pressure release, theoretical analyses, numerical simulations, and field engineering experiments are adopted to study the mining pressure distribution law, plastic zone evolution characteristics and surrounding rock control measures when the working face crosses an abandoned roadway. Mining to the vicinity of the abandoned roadway is equivalent to the process of recovering coal pillars. During the mining process, the width of the coal pillar decreases. Under the influence of mining pressure, the coal pillar will gradually lose its bearing capacity. The overburden rock gravity originally borne by the coal pillar will transfer to the retaining roadway and the coal seam in front of the abandoned roadway. Therefore, it is necessary to strengthen the support of the retaining roadway to prevent large deformations due to the sudden increase in pressure. Within 20 m near the abandoned roadway, based on the original NPR constant resistance large deformation cable (CRLD cable) support scheme, the second row of the CRLD cables is densely arranged, and the cable spacing is encrypted from 2400 to 800 mm. The successful application of these research results in actual engineering applications can provide a useful reference for working faces under similar geological condition.
               
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