True 3D geomechanical model test for research on rheological deformation and failure characteristics of deep soft rock roadways. (October 2022)

• Record Type: Journal Article
• Authors: Zhu, Qingwen; Li, Tingchun; Zhang, Hao; Ran, Jinlin; Li, Hui; Du, Yiteng; Li, Weiteng
• Is Part Of: Tunnelling and underground space technology. Volume 128(2022)
• Publication Date: 2022-10
• Subjects: Soft rock roadway -- 3D geomechanical model test -- Rheology deformation -- Full section convergence -- Floor heave; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2022.104653
• Languages: English
• ISSNs: 0886-7798

Abstract

Highlights: Study full section convergence rheological deformation law of soft rock roadways. Research the internal key deformation area and migration law of the surrounding rock. Study the temporal evolution characters of the roadway stress and the bolt force. Analyze the mechanisms of ceaseless floor heave of the deep soft rock roadway. Abstract: Deep soft rock roadways generally present large deformation characteristics, and a vast number of workers attempt to repair them to no avail. A true 3D model test was performed based on the engineering background of the transportation roadway of the Huafeng coal mine in China. The selected analogous materials have a significant time similarity relationship with the surrounding rock, and a similar bolt-mesh-shotcrete support structure, according to the engineering background, was applied to the roadway. The test results showed that the evolution process of the rheological deformation of the roadway is two sidewalls → floor → vault → full-section convergence of the roadway. The large deformation zones of the surrounding rock are constantly transferred from the surface to the depth, and the bearing capacity of the bolts decreases rapidly after the deformation of the anchorage zones. The mechanical characteristics of the floor determine that the lower surrounding rock always repeats the failure process of the upper rock stratum, and the floor heave does not stop. The test results revealed the full-section convergence rheological deformation laws and migration laws of the internal key deformation locations of the surrounding rock and clarified the reasons for the floor heave. The model test results are verified through field monitoring, and opportunities and suggestions for secondary support are determined. These results could provide a reference for the failure process and control technology of the same type of deep soft rock roadway.