Abstract:By using the mid-low-pressure multi-function CT special seepage experiment equipment,the experimental study on real-time CT observation of sandstone under seepage and 3D stress is carried out. Considering the comparability of test results,the normal triaxial tests on dry specimens and triaxial tests on seepage specimens are observed by X-ray CT scan in real-time,respectively,and the initial results that the seepage affects the sandstone damage evolution are obtained. In accordance with the stress and strain curves,the strength calculation formulas of test specimens and deformation discount rate are introduced,and the relative relations of CT value of dry test specimens and seepage test specimens with stress are analyzed. At the same time,the image measuring method to determine the width of cracks is proposed. The paper also introduces the numerical calculation method with which the width of cracks is determined according to the relative relations between the average CT data and measuring areas