水对岩石变形过程中电阻率变化的影响  

Influence of water on electric resistivity of deforming rock samples

作　　者：张流[1] 黄建国[1] 高平[1] 

机构地区：[1]中国地震局地质研究所,北京100029

出　　处：《地震》2003年第1期8-14,共7页Earthquake

基　　金：九五"地震科技攻关项目(95-04-03-02-01)

摘　　要：实验研究表明:在变形破坏过程中,干燥砂岩电阻率略有下降,变化幅度小;少量含水的砂岩电阻率下降幅度大;含水量多的砂岩电阻率有下降-上升-下降的变化,变化幅度又小;而完全水饱和的砂岩除初期电阻率有所下降外,变化更小。更精确的观察表明:干燥砂岩,破裂前电阻率有升高的迹象;少量含水的样品,破裂前电阻率单调下降;含水量较多和水饱和的样品,破裂前电阻率有先升高后降低的变化。这些有可能给出中短期前兆特征的提示。对电阻率变化的机理给出了解释。Experimental result shows that the electric resistivity of dry sandstone sample decreases slightly during deforming processes. It decreases with huge amplitude during this process for the samples containing rare water and decreases firstly, then increases and decreases again for the samples containing more water. It changes very small except decreasing at the beginning of deformation for the samples saturated with water. The result of more accurate observation show that before fracturing, the electric resistivity rises slightly for dry sample, keeps decreasing for samples containing rare water, and first increases then decreases for sample containing more water or saturated. These results may present some hints to the characteristic of middleand shortterm earthquake precursors. Some explanation is given to the mechanism of the change of electric resistivity.

关 键 词：岩石 电阻率 变形过程 水 地震前兆 

分 类 号：P315.722[天文地球—地震学]