深部岩石隐性裂纹的电化学检测机制

DETESTABILITY MECHANISM OF DEEP ROCK LATENT CRACK USING ELECTROCHEMICAL METHOD

岩体工程进入深部以后,出现许多不同于浅部工程的力学现象,使得岩石力学进入了一个新的阶段。为了研究处于深部岩石中的微裂纹,在分析亚微观裂纹相对尺寸和稳定状态的基础上,从静态和动态变化两个角度把亚微观裂纹分为隐性裂纹和显性裂纹,根据深部岩体工程的力学环境,从分子力学和断裂力学角度分析岩石微裂纹的成核扩展微观机制。运用电化学的基本原理,分析岩石微裂纹和其间溶液的界面性质,以及其组成的双电层结构的电化学性质,研究岩石微裂纹扩展引起该体系双电层电容和宏观阻抗的变化规律,并以泥岩为例研究岩石的交流阻抗谱特征参数和裂纹成核扩展的关系。结果表明:利用电化学手段可以检测岩石微裂纹的成核扩展,为进一步研究岩石的断裂行为提供新的检测手段。

There are many different mechanical phenomena in deep rock engineering comparing with shallow- buried rock engineering. To research the microcrack of deep rock, the relative size and stable conditions of microcracks are analyzed; and the microcracks can be classified into latent crack and overt crack with the reference of the static and variable states. The mechanical phenomena of nucleation and expansion of deep rock microcracks are studied. Based on the basic theory of electrochemistry, the interface properties of rock microcrack and its solution are analyzed; and the electric double layer structure composed of rock microcrack and solution is studied. The change law of the electric double layer capacitance and its macroscopic impedance due to expansion of rock crack are researched. The relations between the specific parameter of rock AC impedance spectroscopy and the nucleation and expansion of rock microcrack are investigated. The result shows that the electrochemical method is effective to test expansion of rock crack. It is a new method to study rock fracture behavior.