New Progress in Real-time Detecting of Geotechnical Experiment by Use of X-ray Computed Tomography
DING Wei-hua, WU Yan-qing, PU Yi-bin, LIAO Quan-rong (State Key Laboratory of Frozen Soil Engineering, CAREERI, CAS, Lanzhou Gansu 730000, China) (Xi'an University of Technology, Xi'an Shanxi 710048, China)
In this paper the current status of real-time detecting in geotechnical experiment by use of CT is analyzed and a new concept, density damage increment, is proposed. On the basis of X-ray physics and the hypothesis that mineral can not be compressed, a relationship between CT number of a pixel and the density damage increment of a corresponding volume element is deduced. The advantage of the new concept is that it has definite physical senses and can quantitatively describes the damage degree of a rock at any stress state and at any location. The density damage increment image is analyzed with the new concept, and several conclusions can be come. The first conclusion is that in one △Dimage the density variation of every corresponding volume element comparing with the initial one can be read. The second conclusion is that the △Dvalue in one △Dimage varies very much, which is very important in the rock mass engineering analysis that can provide more damage information at most location of the rock. The third conclusion is that the △Dimage can distinguish better than the traditional CT image analysis method. Be- cause the detecting of the density damage increment can be realized, a real meso-damage process of rock can be detected and some good experiment data will be obtained for the relation between the meso- damage process and the macroscopy constitutive law of a rock. A new progress of using CT in geotechnical experiment is made.