Abstract: Moraine soil is a kind of special geotechnical material generated by rapid mixed depositing of boulders, gravel, sand, silt and clay without sorting when quaternary glacier moving and melting. Engineering problems caused by moraine soil have attracted more and more attentions from geotechnical engineering field. Meso-fabric of gravel particles is a reflection of the unique sedimentary history and directly affects the geotechnical properties of moraine soil. However, subjecting to the hardness of obtaining undisturbed moraine soil samples, there is few researches on it. To change this situation, we succeeded in getting undisturbed moraine soil samples from west Yulong Snow Mountain with delicate manual cutting work. Then the 6 pieces of moraine soil samples are scanned by CT instrument and the real meso-fabric images of internal moraine soil are obtained for the first time. After binarization of CT images and de-noising processing with the help of Matlab, section fabric indexes of stone area ratio, grain orientation and particle shape of moraine soil gravel particles are given with conventional statistical methods. The results show that the difference between vertical sections is minor, however the difference between vertical and horizontal sections is significant.

Key words: moraine soil, intact samples, CT scanning, meso-fabric, statistical study, Yulong Snow Mountain