An Experimental Investigation on the Characteristics of Excavation-Induced Failure of Rocks Surrounding a Shaft
A series of true triaxial compression (TTC) tests was conducted on granite specimens to investigate their fracture behavior. The granite was sampled from a 1500-m-deep exploration borehole located on the Sanshandao gold field in Shandong Province, China, where a 1915-m deep vertical shaft was planne...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2024-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/adce/7363711 |
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| Summary: | A series of true triaxial compression (TTC) tests was conducted on granite specimens to investigate their fracture behavior. The granite was sampled from a 1500-m-deep exploration borehole located on the Sanshandao gold field in Shandong Province, China, where a 1915-m deep vertical shaft was planned. Under true triaxial stress, the fracture of the granite specimen shows anisotropic characteristics, which is manifested as different strains in the three directions of the specimen, and the macroscopic fractures formed are parallel to the direction of maximum principal stress σ1 and intermediate principal stress σ2. In addition, the effects of the intermediate principal stress σ2 and the minimum principal stress σ3 on the fracture of granite specimen are different. A higher σ2 causes the post-peak curve of the granite specimen to develop toward a Class-II type of curve, and the failure mode develops toward splitting failure, while a higher σ3 causes the post-peak curve of the granite specimen to develop toward a Class-I type of curve, and the failure mode develops toward shear failure. In particular, under the stress regime whereby σ3 = 0, σ2 = 40 MPa, it simulates the tangential stress adjustment process when the shaft is excavated to a depth of 1000 m. The fracture mode of the granite specimen and the post-peak curve characteristics both indicate that the shaft excavation to this depth has the risk of inducing a strain burst. |
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| ISSN: | 1687-8094 |