Study on mechanical properties of porous rock by CT technique

摘要

In order to accomplish on-line observation when CT scanning and disclose the evolution rules of microscopic porous structure and cracks propagation of porous rock under loading conditions, a set of CT loading device had been developed by ourselves. Using the CT loading device and CT scanning technology, the Brazil split tests of porous rock were carried out. The evolutionary laws of porous structures of rock were observed and analyzed during a split. The intrinsic mechanisms of split failure in porous rock are revealed. The results show that the macroscopic failure properties of rock feature obvious elastic and brittleness that are independent of the quantity and distribution of pores during a split. On the contrary, the change of inner porous structures and response of stress state tightly depend on the distribution properties and geometric deformations of pores. With the porosity increase, the split cracks deviate from lengthways symmetry axis and the partial pores present visibly irreversible deformation.