Application of Concrete-filled Steel Tube Support in the Repairing of 1000m-deep Roadway

Covered 1 010 ～ 1 230 m underground,the second level of Xingdong coal mine is a 1 000 m-deep roadway.Due to the surrounding heavy loads of the rock mass and the low strength of the coal mass,serious deformation had occurred to the roadway.Therefore,even though the roadway had been repaired many times,it remained unstable.To solve the difficult problem of the roadway support,solutions consisting of an oval concrete-filled steel tube support and grouting reinforcement were designed after full analysis was made on the geological conditions of the roadway and on the deformation properties of the original support structure.The concrete-filled steel tube support was divided into two types,i.e.,the φ194 × 8 basic support type and the φ194 × 10 strengthened support type.The supporting reaction forces of the two support types reached 1.1 MPa and 1.23 MPa respectively.Half a year has passed since the support has been adopted,the roadway remains stable and no visible deformation has occurred.The practice shows that the concrete-filled steel tube support possesses high load-bearing capacity and can be used as reliable support for 1 000 m-deep roadways.