Characteristics and implications of stress state in a gold mine in Ludong area, China

In this study, we obtained information from twenty-one measurement points on the stress magnitudes and orientations of a gold mine in the Ludong area. We used the overcoring technique with an improved hollow inclusion strain gauge and then analyzed the distribution characteristics of the in situ stress field. The results indicate that the stress field is characterized by σ_H > σ_h > σ_v and σ_H > σ_v > σ_h (where σ_H, σ_h, and σ_v are the maximum horizontal, minimum horizontal, and vertical principal stresses, respectively). The regional stress field is dominated by horizontal principal stress. The σ_H, σ_h, and σ_v values show a gradual increasing trend with depth. The σ_H is predominantly oriented in the NWW-SEE or near-EW direction. We also confirmed the correspondence between the measured stress field and the regional geological structure. In addition, based on the measured stress data, we discuss the implications of the in situ stress with respect to fault activity in the mine area.