Analysis of technical measures for controlling instability of surrounding rock in jointed rock masses

The development and utilization of underground space is an inevitable choice for the development of human society, economic construction, and national security strategy. The failure mechanism of the chamber in underground rock mass engineering is extremely complex, and its stability analysis and control have always been the key problems in the field of rock mechanics. In practical engineering, due to the complexity of the structural plane shape, unreasonable layout, increasing buried depth, and great disturbance of underground rock engineering, the stress concentration in the surrounding rock is intensified, the surrounding rock is extremely sensitive to the change of external load, and the stability state is prone to mutation, resulting in the instability and failure of the chamber structure. In this article, based on the previous theoretical research results and engineering practice experience, the instability control theory of surrounding rock of jointed rock masses on the bases of four basic principles of “consolidating surrounding rock joints, improving surrounding rock strength, restoring and improving stress state, and weakening dynamic disturbance source strength” was proposed. On this basis, to maintain the stability of the surrounding rock of the chamber, the chamber support form of “grouting reinforcement + full-face bolt (mesh) shotcrete combined support + local strengthening support + constructing impact buffer structure + reducing engineering blasting disturbance” was put forward. Moreover, the technical measures for controlling the instability of the surrounding rock of the chamber in jointed rock masses were established, and the technical scheme of joint application and step-by-step implementation was suggested. In addition, the principle of considering the safety and economy of support and the necessity of establishing a multi-parameter real-time joint monitoring and early warning system were discussed. The research results can provide a certain reference for the stability control of surrounding rock in jointed rock masses in similar projects.