Stress measurement with hydraulic fracturing technique in Ekou Mine

In—situ stress measurements with hydaulic fracturing technique at 4 borcholes 140m to 250m deep have been carried out. It was found that horizontal stress is much higher than vertical stress (gravity) which indicates that residual tectonic stress field still exists in Ekou Open—Pit Mine. Large horizontal stress will be a key factor to influence the slope stability of the mine.