2006 Fiscal Year Final Research Report Summary
A study on the electrical potential and long term strength of rocks during cyclic deformation
| Project/Area Number |
15560435
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Geotechnical engineering
|
|---|
| Research Institution | Toyota National College of Technology |
|---|
Principal Investigator |
ITO Takashi Toyota National College of Technology, Civil Engineering, Professor, 環境都市工学科, 教授 (50193496)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
AKAGI Tomoyuki University of the Ryukyus, Engineering, Professor, 工学部, 教授 (90006685)
|
|---|
| Project Period (FY) |
2003 – 2006
|
| Keywords | prediction of failure / electrical potential / cyclic loads / AE measurement / slop |
|---|
| Research Abstract |
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.
|
