Deformation mechanism and control technology of roadway in deep mine with high stress and weak surrounding rock

In order to solve the support problems caused by large deformation failure of high-stress soft surrounding rock roadway in deep mine, with a track roadway at working face 3209 in eastern mine as research object, the failure characteristics and deformation mechanism have been studied through field investigation and test, rock mechanics experiment and theoretical analysis. The results have shown that the high-stress weak surrounding rock roadway in deep mine is characterized by fast deformation in early stage, large accumulated deformation in total, long duration deformation and four-side deformation. The main reasons for deformation include combined effect of high ground stress, weak surrounding rock, large section and unreasonable support, and the complex deformation mechanical mechanism behind it is compound type of IIABDIIIBCE. Based on the study above, a new technical control scheme has been proposed, which contains the core key technologies: high prestressed and high strength bolt support, strong support for key parts, full-section coordinated support, and combination of rig id-flexible support. And the key control technology has been analyzed thoroughly. The field-test results have shown that the deformation of surrounding rock tends to be stable after 22-26 d in the new technical scheme. The average two-side convergence and the average roof-to-floor convergence are 372 mm and 344mm respectively, which decreased by 75.2% and 71.3% comparing with the original scheme. The support effect is significant, which can meet the requirements of safe production. © 2020, Editorial Board of Journal of Mining & Safety Engineering. All right reserved.