Abstract
Reliable estimation of the in situ state of stress for underground mine design purposes is still a difficult problem due to the typically few measurements made, combined with variability in both orientation and magnitude of principal stresses between measurements. For the case of deep seismically active mines, this led to the investigation of seismic stress inversion as another source of stress field information. However, the method only produces partial stress tensor information of principal stress orientations and relative magnitudes. In order to remove this limitation and recover the full stress tensor, the relationships between principal stress components was investigated. Stress measurements from several mines in various locations have been analyzed to determine the relationships between principal stresses and their correspondence relative stress ratio (R value). The results showed that there is a relationship between Sigma1/Sigma2 and Sigma2/Sigma3 versus R. These relationships are site dependent and can be used to recover the full stress tensor using seismic stress inversion.