Experiment of Powerful Anchor Truss Support System Applied to Mining Roof Falling Gateway

The bolt and anchor support effect of the transportation gateway with a large span faling roof by the serious mining pressure role in Xinyuan Mine of Yan gquan Coal Mining Group was poor.Based on the analysis on the site investigation and the anchor measurement information, the paper provided the new support syste m with the powerful anchor and truss as well as the small diameter high pre-stressed anchor combined support.The study showed that under the support role, the partia | strata of the roof in the gateway would form a double arch strong stress zone.The paper analyzed the double arch coupling support mechanism.One section of the Eas t No.4 transportation gateway was taken for a trial and the KZL-300 mode roof bed separation value automatic recorder was applied to record the value of the gateway bed separation.The results showed that with the powerful anchor truss and short anchor combined support system, the bed separation value of the trial section in the g ateway would be only about 6. 12 mm in average.During the gateway services period, the displacement of the roof and the two side wall in the trial section would be red uced by 71.90% and 57.45% individually than other transportation gateway.After twice and more serious mining influences, the gateway would be stabilized and the saf ety construction operations in the underground mine could be ensured.