Rock Strength Evaluation during Progressive Failure Process Based on Fractural Characterization |
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| Authors: | Bin Yu Jun Zhao Yunliang Tan Jianguo Ning |
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| Institution: | 1. Datong Coal Mine Group Company, Datong, China;2. State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology, Department of Engineering Mechanics, Shandong University of Science and Technology, Qingdao, China |
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| Abstract: | A series of laboratory tests was performed to study the decrease of the rock strength during its progressive failure process. Hoek–Brown criterion was adopted as the means to estimate rock strength. The parameters m and s of the criterion for different stages of progressive failure process were derived from the results of triaxial tests. To better evaluate the strength changes over a very wide range of length scales, fractals were introduced to describe the fractures of rock for each stage. Based on the test results, liner fitting expressions were used to approximate the relationship between the fractal dimension D of surface crack and parameters m and s to reflect the strength change of the rock with different fracture state for both model and full scales. |
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| Keywords: | fractal dimension Hoek–Brown criterion rock strength triaxial compressive test |
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