Analytical Solution of the Grouting Reinforcement Response of a Circular Cavern in Deeply Buried Fractured Surrounding Rock under a Nonuniform Stress Field.

Abstract

Grouting is widely utilized to reinforce fractured surrounding rock. However, presently, the secondary stress distribution of fractured surrounding rock after grouting is not distinct, which hinders the accurate evaluation of the grouting effect. Therefore, a complex variable function solution is provided for the evolution of the stress field and the displacement field around the reinforced fractured surrounding rock subjected to a nonuniform load. By comparing the evolution of the stress and radial displacement fields around the cavern, the reinforcement effect on the fractured surrounding rock is quantitatively confirmed. The results show that grouting has an obvious modification effect on fractured surrounding rock: its radial stress and circumferential stress fields are affected to different degrees, and the circumferential stress is more obvious. Grouting makes the circumferential stress peak transfer from the wall of the cavern to the roof and floor of the cavern, which is beneficial to the stability of the cavern. The radial displacement around the cavern also decreases. The displacement of the wall decreases by approximately 24.0%, and the radial displacement of the roof and floor decreases by approximately 61.8%.