Research on Instability Mechanism and Supporting Countermeasures of Weakly Cemented Roadway in Adjacent Chamber Group Engineering

Taking the roadway of a mine in West Mengxi area as the research object, the correlation law between the stress increment of the chamber group and the surrounding rock deformation of the roadway is obtained, and reveals the influence mechanism of adjacent chamber group engineering stress transfer on the deformation of weak cement roadway surrounding rock. The results show that the deformation of the weakly cemented roadway in the adjacent chamber group engineering presents asymmetric and differential characteristics. The properties of surrounding rock, the original rock stress and the chamber group engineering are the main factors of roadway failure; the influence distance of the vertical stress of the surrounding rock in the chamber group engineering area is 7 ~ 12 times the height of the roadway, the stress concentration of the weakly cemented surrounding rock is mainly affected by the vertical stress transmitted from the chamber group engineering area. The vertical stress increment range of the surrounding rock of the adjacent chamber group engineering roadway ranges from 3.2 to 4.8 MPa, compared with the initial in-situ stress which increased by 32–48%, exceeding the critical value of surrounding rock fracture which leading to instability of weak cemented roadways.