Failure Mechanism and Control of Lower Retracement Channel in Close-Distance Double-Thick Coal Seams

Under the condition of close-distance double-thick coal seams’ mining, serious strata behavior occurred in lower retracement channel, which is affected by double disturbance with upper coal-pillar static load and mining dynamic pressure. Field investigation, laboratory test, numerical simulation were used to study failure characteristics stress distribution N0381 channel. The results show that plastic surrounding rock are obviously asymmetric; specifically, closer roof gob, stronger is. In addition, when pillar critical stable or state ( w / h > 2 ), high concentration transmitted downward through floor so two dangerous areas severe formed view this, a partition control strategy “high-pressure water jet + asymmetric high-strength cable-beam net three-hole anchor cable group grouting” as core proposed ensure stability This provides reference for mines similar production geological conditions.