A study on the electrical potential and long term strength of rocks during cyclic deformation

岩石的电势响应一直受到特别的关注，因为在地震发生之前和发生期间会出现一些明显的电势变化，这些变化被用来预测地震。最近的实验研究表明，岩石在变形和破裂过程中表现出明显的电势变化。这意味着它也可以用于评价岩石结构的稳定性。本研究对认识岩石在蠕变和循环加载过程中变形引起的电势有进一步的实验贡献。从本报告所描述的实验结果可以得出以下结论：实验结果清楚地表明，变形、破裂过程在岩土材料中诱发电位。峰状电信号与试样轴向应变的突然增大直接相关，是微破裂的明确指示。破坏前，观察到明显的地震电信号。可以肯定地说，当不稳定断裂过程开始时，将观察到最大的地震电信号。由于这些原因，电势测量技术作为岩石破坏预测技术之一，可以转化为声发射测量，这表明电势测量技术是有效的。

The electrical potential response of rocks has been receiving a particular attention since some distinct electric potential variations occur before and during earthquakes occurs, and they are used for the prediction of earthquakes. Recent experimental studies showed that rocks exhibit distinct electric potential variations during deformation and fracturing processes. This implies that it can be also used in the assessment of the stability of rock structures. This study is a further experimental contribution to the understanding of the electric potential induced by the deformation of rocks during creep and cyclic loading. From the experimental results described in this report, the following conclusions may be drawn :1.The experimental results clearly indicate that the deformation, fracturing processes induce electric potential in geomaterials.2.The spike-like electric signals are directly associated with the sudden increase of axial strain of the sample, which are a clear indication of micro fracturing. Before the failure, distinct seismic electric signals are observed. It can be firmly stated that the largest seismic electric signals will be observed when the unstable fracture process starts.3.As one of the prediction technique of rock failure which could turn into an AE measurement as a result of these more, it became clear that electric potential measurement technique was effective.