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Abstract In order to describe the damage evolution state of sandstone during the uniaxial compression comprehensively and objectively，a joint test method combining electrical resistivity and acoustic emission(AE) has been proposed. And the electrical resistivity and AE response characteristic of 30 sandstone samples during the whole process of uniaxial compression have been studied. The results show that there are strong regularity and complementarity between electrical resistivity and AE information. In the stages of compaction，elastic deformation and plastic deformation，the electrical resistivity is more sensitive to the fissure initiation and development activities；while the AE signal is relatively weak. At the moment of rock samples fracture，electrical resistivity and AE information increase suddenly and the AE information has better synchronicity and sensitivity. Then，after the rock samples fracture，electrical resistivity information still has some changes and tends towards stability；while the AE information restores to a low level. At the same time，the analytic expressions of damage variable based on electrical resistivity have been derived. According to the complementarity between electrical resistivity and AE damage variables，a comprehensive damage variable has been defined；and the damage evolution equations of typical rock samples are obtained. In addition，the precursor characteristic of rock fracture and a status qualitative criterion for rock damage and failure have been proposed. Through comparing the between theoretical stress-strain curve with experimental one during the whole process of uniaxial compression，it is shown that the comprehensive damage variable can reflect and describe the rock samples damage evolution comprehensively and objectively.
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Received: 18 January 2013
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2014, Vol. 33 
