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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.

Rock burst is one typical dynamic disaster caused by excavation in deep underground engineering. High-stress unloading test is a common research method for rock bursts. Due to the limitation of laboratory test conditions, it is difficult to monitor the energy release and dissipation information during rock bursts in the unloading test. But the study of energy evolution law is more helpful to reveal the essential characteristics of rock burst. Therefore, the energy evolution process and ejection failure characteristics of granite after unloading were analyzed through the unloading simulation test in this paper, and the influence of unloading velocity, lateral stress, and axial stress were researched. The microstructure numerical model of the granite was established by using digital image processing technology and PFC2D software, aiming to match the real granite. The energy evolution process of unloading granite can be divided into three stages, namely the whole energy rapid release stage, sidewall energy slow-release stage, and rock block ejection stage. The area near the unloading sidewall is the main energy release and rock block ejection area. In the whole energy rapid release stage, the energy release velocity and dissipation velocity show similar law, i.e., a positive power function correlation with unloading velocity, a negative power function correlation with lateral stress, and a positive linear function correlation with axial stress. In the rock block ejection stage, with increasing the unloading velocity and axial stress, the rock block ejection force increases as a power function, while it decreases with increasing lateral stress. This research is an important supplement to the laboratory unloading test. It has theoretical guiding significance for rock burst hazard assessment during excavation in deep underground engineering.

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