Abstract: For rock stability of chamber group in extremely week cementation stratum in central substation of west No.1 mine in Wujianfang, with combination of field tests, numerical simulations and site monitoring, the deformation law of surrounding rocks and the stability control program under several construction disturbances in chamber group and its adjacent roadway are obtained. A composite supporting scheme is proposed, that is, the steel mesh/shotcrete+ arch support is adopted as the first supporting, the concreting supporting scheme with the single layer steel reinforcement is used as the second supporting and advance support or temporary support is at intersection point. The field experiment shows that the stability of chamber group and adjacent roadway is relatively good and such supporting scheme reaches an ideal supporting effect. The scheme provides a certain reference for the construction of chamber groups in the extremely week cementation stratum.

Key words: Extremely weak cementation, Chamber group, Construction disturbance, Numerical simulation, Surrounding rock stability