岩石应力腐蚀的实验研究及其与震源过程的关系

理论研究1]表明,环境水介质的动态对岩石中裂缝的应力腐蚀过程有很大的影响。但迄今为止,岩石的应力腐蚀实验都是在水介质静止情况下作的。本实验对比研究了蒸馏水静止和流动情况下云南大理岩试件应力腐蚀引起的亚临界裂缝扩展特征。结果表明,裂缝周围水介质的流动会加速裂缝端部的应力腐蚀过程,这对于震源过程及临震前兆的研究可能有重要意义。样品采用紧凑拉伸试件,同时测量了断裂韧性K_(Ic)=(1.41±0.013)kg·mm~((-3)/2),并对人工狭窄锯口与天然初始裂缝的试件进行了对比测量,认为对于云南大理岩的紧凑拉伸试件可以用人工狭窄锯口代替天然初始裂缝。

EXPERIMENTAL STUDY ON STRESS CORROSION IN ROCK AND THE RELATION WITH EARTHQUAKE SOURCE PROCESS

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.