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| EXPERIMENTAL STUDY OF THREE-DIMENSIONAL CHARACTERIZATION OF COAL FRACTURES BASED ON STEREOLOGY |
| ZHANG Qingcheng1，ZUO Jianmin2，MAO Lingtao1 |
(1. School of Mechanics and Civil Engineering，China University of Mining and Technology，Beijing 100083，China；
2. Beijing Sai Bosi Architectural Design Co.，Ltd.，Beijing 100044，China) |
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Abstract Scanning experiments under uniaxial loading for coal samples were carried out using the industrial computerized tomography(CT) experiment system based on the principle of stereology. The curves were obtained by calculating the sum of squared eigenvalues of crack tensor with different threshold values for CT images. The inflection point of the curve was taken as the threshold which was verified to be the best threshold value for calculation of the second order tensors. The binary image line and the eigenvalues of regional parameters by the binary stereological image were obtained. The sum of squared eigenvalues was proposed as the parameter of coal specimen damaging. Three orthogonal surfaces of fractures of the reconstructed three-dimensional coal specimen were selected to calculate the relationship between the squared eigenvalues of second order tensor and the porosity，which could provide a reference for describing crack damage in three dimensions.
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Received: 31 July 2013
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2014, Vol. 33 
