Theoretical studying⁽¹⁾ has indicated that the behaviour of surrounding medium of water has a large effect on the stress corrosion process of fracture in rock. So far, experiments made for stress corrosion in rock have been done under the situation of static water. In this experiment, the subcritical develop characteristics of fracture caused by stress corrosion n Yuennan marble samples under the situation of static and flowing distilled water have been studied respectively. The results show that flowing of the medium of water around fracture may accelerate the stress corrosion process of the end of fracture. It is perhaps of great significanse to the study of earthquake source process and the precursor just before earthquake.
The Compact Tensile (CT) samples have been used and the stress intensity of Yuennan marble has been measured. The fracture toughness of Yuennan marble was found to be K_IC=(1.41±0.03)kg·mm^-3/2. The results of man-made narrow cut samples and natural initial fracture samples have been compared. It is therefore supposed that the natural initial fracture sample may be substituted by man-made narrow cut sample for the fracture toughness measurement of Yuennan marble CT samples.