岩石破坏与电阻率变化特征研究

Research on Rock Failure and Resistivity Variation Feature

利用四极法进行了泥岩、灰岩和砂岩破坏过程中的电阻率变化特性测试。试验表明,岩石的孔隙特征和含水量状况是影响电阻率变化的关键因素。在压密阶段,当试样含水量较少,偏干燥时电阻率变化幅度一般不大;在弹性-稳定破裂阶段,电阻率整体上呈现为较平稳的状况;在屈服阶段,岩石电阻率在屈服点附近电阻率值存在陡变现象,且该现象与岩石的裂隙发展及扩容现象密切相关。

The resistivity of specimens of mudstone,limestone and sandstone are measured along loading process by quadrupole method. From the test results,it is shown that the pore characteristic and moisture content are the key factors of resistivity variation. In the compaction stage,when the moisture content in the sample is low, the magnitude of the resistivity change in general is not big. In the elasticstable fracture stage,the resistivity is totally in a more stable situation. In the yield stage, the resistivity is closely related to the development of the fissures and the expansion of the phenomenon when the rock comes to the yield point. Nearby the yield point of stress-strain curve,the resistivity has a mutation phenomenon.