The deformation mechanism and zoning control technology of surrounding rocks of the roof-cutting deep well
The service cycle of gob-side entry retaining is extended,characterized by intense mine pres-sure that often leads to significant deformation of the surrounding rocks in the entry post-mining.This de-formation poses challenges for supporting the mining activities of the lower section working face.Based upon the engineering background of the 1452(1)working face of Dingji Coal Mine for the repair and control of gob-side entry retaining after the first mining operation and re-reinforced support,the shrinkage degree of the entry section was tested on-site and divided into three areas to be repaired with different deformation characteristics.Through theoretical analysis,the deformation mechanism of sur-rounding rocks in entry was analyzed,which was founded that the asymmetric roof deformation was caused by roof breaking,rotation,and repeated compaction of collapsed gangue in the goaf area within the roof-cutting height.Deformation on the coal side was primarily due to high support pressure from mining activities.The load of overlying rocks was transmitted to floor through the solid coal side and the gangue side in the goaf area,resulting in deformation and damage to the floor of the roadway.Based on the principle of minimum potential energy,heaving floor was found to increase linearly with stress con-centration increasing.The minimum main stress distribution of roof and floor was analyzed with numeri-cal simulation after a mining operation to reflect the stress concentration of roof and floor.Optimal time and repair process were determined for repairing entry.The deformation of surrounding rocks in entry was analyzed to propose collaborative support for the hierarchical zoning of the surrounding rock struc-ture.The on-site monitoring results showed that the deformation of the surrounding rocks in entry and the force of the constant-resistance anchor cable were stable when the working face of the lower section was mined.The control technology can control the deformation of the surrounding rocks of the roadway,and allow for the reuse of entry retaining.
gob-side entry retainingroof-cutting pressure reliefsurrounding-rock controlrepair and controlreinforcement support
万方数据
维普
